Background and aimsInternet gaming disorder (IGD) is known to cause various psychological and phy... more Background and aimsInternet gaming disorder (IGD) is known to cause various psychological and physical complications. Through data collected from an adolescent prospective longitudinal cohort, we examined how IGD is related to lifestyle and physical symptoms, as well as the temporal relationship between them.MethodsThis study was conducted as part of iCURE (Internet user Cohort for Unbiased Recognition of gaming disorder in Early Adolescence) in Korea between 2015 and 2019. Sleep and physical activity time, dry eye symptoms, musculoskeletal pain, and near-miss accidents were measured at baseline and followed-up after one year. IGD risk was evaluated using the Internet Game Use – Elicited Symptom Screen (IGUESS). The association between IGD risk and measured variables was analyzed, both at baseline and at follow-up after one year.ResultsAt baseline, the IGD risk group had significantly less physical activity time and sleep time and had more dry eye symptoms, musculoskeletal pain, and...
International Journal of Environmental Research and Public Health, 2019
Individual characteristics, family- and school-related variables, and environmental variables hav... more Individual characteristics, family- and school-related variables, and environmental variables have equal importance in understanding Internet addiction. Most previous studies on Internet addiction have focused on individual factors; those that considered environmental influence typically only examined the proximal environment. Effective prevention and intervention of Internet addiction require a framework that integrates individual- and environmental-level factors. This study examined the relationships between personal factors, family/school factors, perceived Internet characteristics, and environmental variables as they contribute to Internet addiction among adolescents based on the public health model. A representative sample of 1628 junior high school students from 56 regions in Seoul and Gyeonggi-do participated in the study via questionnaires with the cooperation of the Ministry of Health and Welfare and the district office of education. The study analyzed psychological factors...
Journal of Korean Neuropsychiatric Association, 2019
Alcohol is a substance that has a negative impact on public health according to the various drink... more Alcohol is a substance that has a negative impact on public health according to the various drinking patterns and amount consumed. Alcohol epidemiology covers an investigation of the prevalence of alcohol use disorders, high risk drinking behaviors, and level of consumption per capita. The epidemiologic data of alcohol is an important guide to develop evidence-based alcohol policies. The high rate of drinking among middle aged males and young females is the result of recent socioeconomic changes in South Korea and aggressive marketing from the alcohol industry. The high rate of treatment among middle-aged men indicates that the treatment of alcoholism begins later. Regarding alcohol policy, restrictions on alcohol accessibility and advertisement, and brief intervention systems might help reduce alcohol problems. In addition, a continuum of care system needs to be established to provide timely appropriate treatment and rehabilitation services.
Objectives This study evaluated whether parent-child attachment and self-esteem may mediate a rel... more Objectives This study evaluated whether parent-child attachment and self-esteem may mediate a relationship between parental marital conflict and increases in features of internet gaming disorder (IGD) in children at one year. Method Baseline and one-year follow-up data for 268 children from the iCURE study were collected. The students were “non-cases of high risk of IGD” in the initial self-reported assessment, anyone living with both parents, current game users at baseline, and those who completed a 12-month follow-up assessment. The Internet Game Use-Elicited Symptom Screen (IGUESS) was used to identify increases in IGD features at 12 months. To examine a potential mediation effect, structural equation modeling was performed. Results The direct effect was statistically significant, and parental marital conflict at baseline significantly predicted increases in IGD features in children at the 12-month follow-up after adjusting for gender, sex, socioeconomic status, and baseline IGUE...
Purpose of Review With increasing use of the Internet throughout our daily lives, Internet use di... more Purpose of Review With increasing use of the Internet throughout our daily lives, Internet use disorders (IUDs) due to addictive behaviors are gaining recognition. As an umbrella term, IUD covers an array of online behaviors that are potentially addictive. The growing population of Internet and smartphone users also raised public health concerns over IUD in regard to adverse cognitive, developmental, psychosocial, and physical consequences. While scientific literature to date has tended to focus on specific forms of IUD such as gaming or pornography, confining our attention to only these specific areas may impede research on the combined effects of multiple online addictive behaviors-often the clinical reality in maladapted Internet use. Taking this broader approach may also facilitate prioritization in policymaking and more efficient allocation of public health and clinical resources. This paper discusses conceptual application of a public health model at the society level and an integrative model at the individual level in IUD intervention strategies. Current treatment modalities of IUD are also reviewed from a biopsychosocial perspective. Recent Findings We propose that the harms of IUD are mediated by (1) risky/harmful content, (2) excessive/maladaptive use, and (3) financial burden. Prevention strategies that reduce the potential negative effects of these mediators may be useful against IUD. Summary Prevention and intervention efforts against IUD should not only target the "host" (individual vulnerabilities) but also the "agent" (media-related risks) and "environment" risks to better address complexities in the phenomena. The current mainstream therapeutic modality is psychosocial intervention. Further studies on psychopharmacology and neuromodulation are needed to broaden our therapeutic options for IUD.tf
Open and supportive communication between parents and children is known to reduce adolescents'... more Open and supportive communication between parents and children is known to reduce adolescents' delinquent behavior. Recently, the risk of Internet gaming disorder (IGD) has been increasing in adolescents. The purpose of this study was to investigate the mediating effects of parent-child communication styles on the relationship between adolescent aggressiveness and risk of IGD. Participants in this study were 402 first-year students from 4 middle schools in Seoul who enrolled in the Internet user Cohort for Unbiased Recognition of gaming disorder in Early adolescence (iCURE) and completed baseline assessment in 2016. The structural equation model was constructed based on an aggression questionnaire, the Internet game use-elicited symptom screen, a mother-child communication inventory, and a father-child communication inventory. Adolescents' aggressiveness was found to be related to their risk of IGD. The father-child communication style mediated the relationship between aggre...
Background and aims Empirical research into problematic video game playing suggests that overuse ... more Background and aims Empirical research into problematic video game playing suggests that overuse might cause functional and psychological impairments for a minority of gamers. Therefore, the need for regulation in the case of video games (whether governmental or self-imposed) has arisen but has only been implemented in a few countries around the world, and predominantly in Asia. This paper provides a systematic review of current and potential policies addressing problematic gaming. Methods After conducting a systematic search in the areas of prevention, treatment, and policy measures relating to problematic Internet and video game use, papers were selected that targeted problematic gaming policies (N = 12; six in English and six in Korean). These papers served as the basis of this review. Results Policies were classified into three major groups: (i) policy measures limiting availability of video games (e.g., shutdown policy, fatigue system, and parental controls), (ii) measures aimi...
This commentary responds to Aarseth et al.'s (in press) criticisms that the ICD-11 Gaming Dis... more This commentary responds to Aarseth et al.'s (in press) criticisms that the ICD-11 Gaming Disorder proposal would result in "moral panics around the harm of video gaming" and "the treatment of abundant false-positive cases." The ICD-11 Gaming Disorder avoids potential "overpathologizing" with its explicit reference to functional impairment caused by gaming and therefore improves upon a number of flawed previous approaches to identifying cases with suspected gaming-related harms. We contend that moral panics are more likely to occur and be exacerbated by misinformation and lack of understanding, rather than proceed from having a clear diagnostic system.
Objectives：Mental health problems have been found to be more common among juvenile delinquents. T... more Objectives：Mental health problems have been found to be more common among juvenile delinquents. This report assessed the reliability, and validity of the MAYSI-2K(Massachusettes Youth Screening Instrument-2 Korean) in Korean delinquents to examine the utility as a screening measure. Methods：The study consisted of 119 male juvenile youths(mean age 16) who admitted in the probation & detention office. They completed an assessment battery including MAYSI-2K and K-YSR(Korean-Youth Self Report) upon entry. Factor analysis, reliability test, and validity test were conducted. Results：The results of factor analysis represented 14 factors which showed more factor structures in comparison with published factor loadings of 7 in the MAYSI. In factor analysis according to the each subscale of the MAYSI, the internal coefficients of 7 subscales ranged from .142 to .756. Test-retest reliability revealed significant correlations(r= .84). There were significant correlations among subscales of MAYSI-2K and K-YSR. Conclusion：Our findings suggested that MAYSI-2K might be a useful screening measure. But further studies with extended number of subjects and culturally appropriate items are required for clinical utility of the MAYSI-2K in Korean delinquents.
Objectives-The study sets to examine whether the reciprocal effects of physical morbidity and dep... more Objectives-The study sets to examine whether the reciprocal effects of physical morbidity and depression are moderated by subjective age-that is, individuals' perception of themselves as young or old. Method-Data from the two waves of the Midlife in the US study (1995-6, T1; 2004-6, T2) were analyzed using a cross-lagged design. We assessed 3,591 individuals who participated in both waves and provided full data on all the relevant variables (mean age at T1 = 47.4). Depression and the number of chronic illnesses (the indicator of physical morbidity) were measured at both waves and were tested as predictors and outcomes in a cross-lagged model. The moderating role of subjective age was assessed by examining whether T1 variables interacted with subjective age in predicting T2 outcomes. Results-Subjective age moderated the T1 depression-T2 morbidity relationship, so that the relationship was stronger for those with older subjective age. Subjective age did not moderate the T1 morbidity-T2 depression relationship. Conclusion-Older subjective age could be a risk factor for experiencing greater physical morbidity following depression.
Journal of Korean Neuropsychiatric Association, 2015
Mental health is one of the most important issues for disaster survivors, and many studies have r... more Mental health is one of the most important issues for disaster survivors, and many studies have reported higher rates of mental health problems after disasters. Because Japan has experienced frequent earthquakes, tsunami, typhoons, and volcanoes, mental health problems have been a matter of great concern after disasters in Japan. To serve the psychiatric services after the Hanshin-Awaji (Kobe) earthquake, 'Hyogo institute for traumatic stress' was established. And when the disaster caused by the great east Japan earthquake and tsunami occurred, 'National information center of disaster mental health' and 'Disaster psychiatric assistance team' had the important role of reducing mental health problems.
BackgroundAlcohol use disorder (AUD) is a chronic disease with a higher recurrence rate than that... more BackgroundAlcohol use disorder (AUD) is a chronic disease with a higher recurrence rate than that of other mental illnesses. Moreover, it requires continuous outpatient treatment for the patient to maintain abstinence. However, with a low probability of these patients to continue outpatient treatment, predicting and managing patients who might discontinue treatment becomes necessary. Accordingly, we developed a machine learning (ML) algorithm to predict which the risk of patients dropping out of outpatient treatment schemes.MethodsA total of 839 patients were selected out of 2,206 patients admitted for AUD in three hospitals under the Catholic Central Medical Center in Korea. We implemented six ML models—logistic regression, support vector machine, k-nearest neighbor, random forest, neural network, and AdaBoost—and compared the prediction performances thereof.ResultsAmong the six models, AdaBoost was selected as the final model for recommended use owing to its area under the receive...
Biochemical and Biophysical Research Communications, 2008
The dopaminergic neurotransmission system is one of the major factors in development of alcoholis... more The dopaminergic neurotransmission system is one of the major factors in development of alcoholism and also contributes to anxiety and depression. In this study, the associations of the dopamine receptor type 2 (DRD2) polymorphisms with the symptoms of anxiety were analyzed. A total of 573 alcoholics and 273 controls were enrolled in the study from the Korean population. Five DRD2 SNPs, including À32869 A>G, À32768 insdel C, +11890 C>G, +11915 C>T, and +32806 C>T, were genotyped using a TaqMan assay and analyzed with various alcoholic phenotypes. Although no DRD2 polymorphisms were associated with the risk of alcoholism, +32806 C>T and Block2-ht1 showed associations (in dominant models) with both the state anxiety level scale (STAI-S) and the trait anxiety level scale (STAI-T) (P = 0.004 and P = 0.003, and P = 0.01 and P = 0.005, respectively). In addition, the À32768 insdel C also showed positive association with both anxiety level scales in recessive models (P = 0.01 and P = 0.02, respectively).
Rare earth doped BaZrO 3 is one of most promising proton conducting oxides as it has high proton ... more Rare earth doped BaZrO 3 is one of most promising proton conducting oxides as it has high proton conductivity and sound chemical stability. Sintering aids such as ZnO, however, should be incorporated in order to improve poor sinterability. In this study, the effects of adding ZnO on proton conductivity of Ybdoped BaZrO 3 (BZYb) were investigated. From the electrical conductivities measured under various water vapor pressures, concentration and mobility of the proton were obtained. Proton mobility of BZYb with ZnO (BZYb-Zn) was smaller than that of BZYb while hydration enthalpy of BZYb-Zn was more negative than that of BZYb.
Yb-doped BaZrO 3 samples with relative densities higher than 98% were obtained by the addition of... more Yb-doped BaZrO 3 samples with relative densities higher than 98% were obtained by the addition of 4 mol% stoichiometric ZnO, excess ZnO, and excess BaZnO 2 , and sintering at 1300°C for 10 h. The stoichiometric addition of ZnO was most effective in obtaining a homogeneous distribution of Zn throughout the grains and grain boundaries. The Yb-doped BaZrO 3 obtained using a stoichiometric addition of ZnO had the cubic perovskite structure, whereas the others had monoclinic perovskite structures. The highest proton conductivity was obtained when ZnO was added stoichiometrically; the conductivity of Yb-doped BaZrO 3 with stoichiometric ZnO and excess ZnO at 500°C was 0.0012 Scm −1 and 0.0004 Scm −1 , respectively. The results are discussed from the viewpoint of the crystal structure and the defect chemistry.
Dense sintered bodies of the 15–25 mol% Yb-doped BaZrO3 could be obtained at a fairly low sinteri... more Dense sintered bodies of the 15–25 mol% Yb-doped BaZrO3 could be obtained at a fairly low sintering temperature of 1500 °C, by the addition of 1.0 mol% CuO as a sintering aid. The crystal structures changed from orthorhombic (space group: Cmm2) to cubic (space group: Pm3m) by the CuO addition. The proton conductivity of thus-obtained 20 mol% Yb-doped BaZrO3 with the 1.0 mol% of CuO
ABSTRACT In the present study, (La, Sr)CoO3 material was screen-printed as a cathode and as curre... more ABSTRACT In the present study, (La, Sr)CoO3 material was screen-printed as a cathode and as current-collecting layers for planar-type low-temperature solid-oxide fuel cells (SOFCs). The compositional effects of the cathode functional and current-collecting layer on unit-cell performance were investigated using AC and DC polarization experiments. Two different cathode (La, Sr)CoO3 materials, La0.6Sr0.4CoO3 and La0.8Sr0.2CoO3, were examined, and La0.6Sr0.4CoO3 was found to be more effective for increasing the electrocatalytic activation and collection efficiency of the current produced in the cathode reaction. Furthermore, a well-designed architecture for the current-collecting layer was very effective in increasing unit-cell performance by reducing the contact resistance between SOFC cathodes and interconnects.
Background and aimsInternet gaming disorder (IGD) is known to cause various psychological and phy... more Background and aimsInternet gaming disorder (IGD) is known to cause various psychological and physical complications. Through data collected from an adolescent prospective longitudinal cohort, we examined how IGD is related to lifestyle and physical symptoms, as well as the temporal relationship between them.MethodsThis study was conducted as part of iCURE (Internet user Cohort for Unbiased Recognition of gaming disorder in Early Adolescence) in Korea between 2015 and 2019. Sleep and physical activity time, dry eye symptoms, musculoskeletal pain, and near-miss accidents were measured at baseline and followed-up after one year. IGD risk was evaluated using the Internet Game Use – Elicited Symptom Screen (IGUESS). The association between IGD risk and measured variables was analyzed, both at baseline and at follow-up after one year.ResultsAt baseline, the IGD risk group had significantly less physical activity time and sleep time and had more dry eye symptoms, musculoskeletal pain, and...
International Journal of Environmental Research and Public Health, 2019
Individual characteristics, family- and school-related variables, and environmental variables hav... more Individual characteristics, family- and school-related variables, and environmental variables have equal importance in understanding Internet addiction. Most previous studies on Internet addiction have focused on individual factors; those that considered environmental influence typically only examined the proximal environment. Effective prevention and intervention of Internet addiction require a framework that integrates individual- and environmental-level factors. This study examined the relationships between personal factors, family/school factors, perceived Internet characteristics, and environmental variables as they contribute to Internet addiction among adolescents based on the public health model. A representative sample of 1628 junior high school students from 56 regions in Seoul and Gyeonggi-do participated in the study via questionnaires with the cooperation of the Ministry of Health and Welfare and the district office of education. The study analyzed psychological factors...
Journal of Korean Neuropsychiatric Association, 2019
Alcohol is a substance that has a negative impact on public health according to the various drink... more Alcohol is a substance that has a negative impact on public health according to the various drinking patterns and amount consumed. Alcohol epidemiology covers an investigation of the prevalence of alcohol use disorders, high risk drinking behaviors, and level of consumption per capita. The epidemiologic data of alcohol is an important guide to develop evidence-based alcohol policies. The high rate of drinking among middle aged males and young females is the result of recent socioeconomic changes in South Korea and aggressive marketing from the alcohol industry. The high rate of treatment among middle-aged men indicates that the treatment of alcoholism begins later. Regarding alcohol policy, restrictions on alcohol accessibility and advertisement, and brief intervention systems might help reduce alcohol problems. In addition, a continuum of care system needs to be established to provide timely appropriate treatment and rehabilitation services.
Objectives This study evaluated whether parent-child attachment and self-esteem may mediate a rel... more Objectives This study evaluated whether parent-child attachment and self-esteem may mediate a relationship between parental marital conflict and increases in features of internet gaming disorder (IGD) in children at one year. Method Baseline and one-year follow-up data for 268 children from the iCURE study were collected. The students were “non-cases of high risk of IGD” in the initial self-reported assessment, anyone living with both parents, current game users at baseline, and those who completed a 12-month follow-up assessment. The Internet Game Use-Elicited Symptom Screen (IGUESS) was used to identify increases in IGD features at 12 months. To examine a potential mediation effect, structural equation modeling was performed. Results The direct effect was statistically significant, and parental marital conflict at baseline significantly predicted increases in IGD features in children at the 12-month follow-up after adjusting for gender, sex, socioeconomic status, and baseline IGUE...
Purpose of Review With increasing use of the Internet throughout our daily lives, Internet use di... more Purpose of Review With increasing use of the Internet throughout our daily lives, Internet use disorders (IUDs) due to addictive behaviors are gaining recognition. As an umbrella term, IUD covers an array of online behaviors that are potentially addictive. The growing population of Internet and smartphone users also raised public health concerns over IUD in regard to adverse cognitive, developmental, psychosocial, and physical consequences. While scientific literature to date has tended to focus on specific forms of IUD such as gaming or pornography, confining our attention to only these specific areas may impede research on the combined effects of multiple online addictive behaviors-often the clinical reality in maladapted Internet use. Taking this broader approach may also facilitate prioritization in policymaking and more efficient allocation of public health and clinical resources. This paper discusses conceptual application of a public health model at the society level and an integrative model at the individual level in IUD intervention strategies. Current treatment modalities of IUD are also reviewed from a biopsychosocial perspective. Recent Findings We propose that the harms of IUD are mediated by (1) risky/harmful content, (2) excessive/maladaptive use, and (3) financial burden. Prevention strategies that reduce the potential negative effects of these mediators may be useful against IUD. Summary Prevention and intervention efforts against IUD should not only target the "host" (individual vulnerabilities) but also the "agent" (media-related risks) and "environment" risks to better address complexities in the phenomena. The current mainstream therapeutic modality is psychosocial intervention. Further studies on psychopharmacology and neuromodulation are needed to broaden our therapeutic options for IUD.tf
Open and supportive communication between parents and children is known to reduce adolescents'... more Open and supportive communication between parents and children is known to reduce adolescents' delinquent behavior. Recently, the risk of Internet gaming disorder (IGD) has been increasing in adolescents. The purpose of this study was to investigate the mediating effects of parent-child communication styles on the relationship between adolescent aggressiveness and risk of IGD. Participants in this study were 402 first-year students from 4 middle schools in Seoul who enrolled in the Internet user Cohort for Unbiased Recognition of gaming disorder in Early adolescence (iCURE) and completed baseline assessment in 2016. The structural equation model was constructed based on an aggression questionnaire, the Internet game use-elicited symptom screen, a mother-child communication inventory, and a father-child communication inventory. Adolescents' aggressiveness was found to be related to their risk of IGD. The father-child communication style mediated the relationship between aggre...
Background and aims Empirical research into problematic video game playing suggests that overuse ... more Background and aims Empirical research into problematic video game playing suggests that overuse might cause functional and psychological impairments for a minority of gamers. Therefore, the need for regulation in the case of video games (whether governmental or self-imposed) has arisen but has only been implemented in a few countries around the world, and predominantly in Asia. This paper provides a systematic review of current and potential policies addressing problematic gaming. Methods After conducting a systematic search in the areas of prevention, treatment, and policy measures relating to problematic Internet and video game use, papers were selected that targeted problematic gaming policies (N = 12; six in English and six in Korean). These papers served as the basis of this review. Results Policies were classified into three major groups: (i) policy measures limiting availability of video games (e.g., shutdown policy, fatigue system, and parental controls), (ii) measures aimi...
This commentary responds to Aarseth et al.'s (in press) criticisms that the ICD-11 Gaming Dis... more This commentary responds to Aarseth et al.'s (in press) criticisms that the ICD-11 Gaming Disorder proposal would result in "moral panics around the harm of video gaming" and "the treatment of abundant false-positive cases." The ICD-11 Gaming Disorder avoids potential "overpathologizing" with its explicit reference to functional impairment caused by gaming and therefore improves upon a number of flawed previous approaches to identifying cases with suspected gaming-related harms. We contend that moral panics are more likely to occur and be exacerbated by misinformation and lack of understanding, rather than proceed from having a clear diagnostic system.
Objectives：Mental health problems have been found to be more common among juvenile delinquents. T... more Objectives：Mental health problems have been found to be more common among juvenile delinquents. This report assessed the reliability, and validity of the MAYSI-2K(Massachusettes Youth Screening Instrument-2 Korean) in Korean delinquents to examine the utility as a screening measure. Methods：The study consisted of 119 male juvenile youths(mean age 16) who admitted in the probation & detention office. They completed an assessment battery including MAYSI-2K and K-YSR(Korean-Youth Self Report) upon entry. Factor analysis, reliability test, and validity test were conducted. Results：The results of factor analysis represented 14 factors which showed more factor structures in comparison with published factor loadings of 7 in the MAYSI. In factor analysis according to the each subscale of the MAYSI, the internal coefficients of 7 subscales ranged from .142 to .756. Test-retest reliability revealed significant correlations(r= .84). There were significant correlations among subscales of MAYSI-2K and K-YSR. Conclusion：Our findings suggested that MAYSI-2K might be a useful screening measure. But further studies with extended number of subjects and culturally appropriate items are required for clinical utility of the MAYSI-2K in Korean delinquents.
Objectives-The study sets to examine whether the reciprocal effects of physical morbidity and dep... more Objectives-The study sets to examine whether the reciprocal effects of physical morbidity and depression are moderated by subjective age-that is, individuals' perception of themselves as young or old. Method-Data from the two waves of the Midlife in the US study (1995-6, T1; 2004-6, T2) were analyzed using a cross-lagged design. We assessed 3,591 individuals who participated in both waves and provided full data on all the relevant variables (mean age at T1 = 47.4). Depression and the number of chronic illnesses (the indicator of physical morbidity) were measured at both waves and were tested as predictors and outcomes in a cross-lagged model. The moderating role of subjective age was assessed by examining whether T1 variables interacted with subjective age in predicting T2 outcomes. Results-Subjective age moderated the T1 depression-T2 morbidity relationship, so that the relationship was stronger for those with older subjective age. Subjective age did not moderate the T1 morbidity-T2 depression relationship. Conclusion-Older subjective age could be a risk factor for experiencing greater physical morbidity following depression.
Journal of Korean Neuropsychiatric Association, 2015
Mental health is one of the most important issues for disaster survivors, and many studies have r... more Mental health is one of the most important issues for disaster survivors, and many studies have reported higher rates of mental health problems after disasters. Because Japan has experienced frequent earthquakes, tsunami, typhoons, and volcanoes, mental health problems have been a matter of great concern after disasters in Japan. To serve the psychiatric services after the Hanshin-Awaji (Kobe) earthquake, 'Hyogo institute for traumatic stress' was established. And when the disaster caused by the great east Japan earthquake and tsunami occurred, 'National information center of disaster mental health' and 'Disaster psychiatric assistance team' had the important role of reducing mental health problems.
BackgroundAlcohol use disorder (AUD) is a chronic disease with a higher recurrence rate than that... more BackgroundAlcohol use disorder (AUD) is a chronic disease with a higher recurrence rate than that of other mental illnesses. Moreover, it requires continuous outpatient treatment for the patient to maintain abstinence. However, with a low probability of these patients to continue outpatient treatment, predicting and managing patients who might discontinue treatment becomes necessary. Accordingly, we developed a machine learning (ML) algorithm to predict which the risk of patients dropping out of outpatient treatment schemes.MethodsA total of 839 patients were selected out of 2,206 patients admitted for AUD in three hospitals under the Catholic Central Medical Center in Korea. We implemented six ML models—logistic regression, support vector machine, k-nearest neighbor, random forest, neural network, and AdaBoost—and compared the prediction performances thereof.ResultsAmong the six models, AdaBoost was selected as the final model for recommended use owing to its area under the receive...
Biochemical and Biophysical Research Communications, 2008
The dopaminergic neurotransmission system is one of the major factors in development of alcoholis... more The dopaminergic neurotransmission system is one of the major factors in development of alcoholism and also contributes to anxiety and depression. In this study, the associations of the dopamine receptor type 2 (DRD2) polymorphisms with the symptoms of anxiety were analyzed. A total of 573 alcoholics and 273 controls were enrolled in the study from the Korean population. Five DRD2 SNPs, including À32869 A>G, À32768 insdel C, +11890 C>G, +11915 C>T, and +32806 C>T, were genotyped using a TaqMan assay and analyzed with various alcoholic phenotypes. Although no DRD2 polymorphisms were associated with the risk of alcoholism, +32806 C>T and Block2-ht1 showed associations (in dominant models) with both the state anxiety level scale (STAI-S) and the trait anxiety level scale (STAI-T) (P = 0.004 and P = 0.003, and P = 0.01 and P = 0.005, respectively). In addition, the À32768 insdel C also showed positive association with both anxiety level scales in recessive models (P = 0.01 and P = 0.02, respectively).
Rare earth doped BaZrO 3 is one of most promising proton conducting oxides as it has high proton ... more Rare earth doped BaZrO 3 is one of most promising proton conducting oxides as it has high proton conductivity and sound chemical stability. Sintering aids such as ZnO, however, should be incorporated in order to improve poor sinterability. In this study, the effects of adding ZnO on proton conductivity of Ybdoped BaZrO 3 (BZYb) were investigated. From the electrical conductivities measured under various water vapor pressures, concentration and mobility of the proton were obtained. Proton mobility of BZYb with ZnO (BZYb-Zn) was smaller than that of BZYb while hydration enthalpy of BZYb-Zn was more negative than that of BZYb.
Yb-doped BaZrO 3 samples with relative densities higher than 98% were obtained by the addition of... more Yb-doped BaZrO 3 samples with relative densities higher than 98% were obtained by the addition of 4 mol% stoichiometric ZnO, excess ZnO, and excess BaZnO 2 , and sintering at 1300°C for 10 h. The stoichiometric addition of ZnO was most effective in obtaining a homogeneous distribution of Zn throughout the grains and grain boundaries. The Yb-doped BaZrO 3 obtained using a stoichiometric addition of ZnO had the cubic perovskite structure, whereas the others had monoclinic perovskite structures. The highest proton conductivity was obtained when ZnO was added stoichiometrically; the conductivity of Yb-doped BaZrO 3 with stoichiometric ZnO and excess ZnO at 500°C was 0.0012 Scm −1 and 0.0004 Scm −1 , respectively. The results are discussed from the viewpoint of the crystal structure and the defect chemistry.
Dense sintered bodies of the 15–25 mol% Yb-doped BaZrO3 could be obtained at a fairly low sinteri... more Dense sintered bodies of the 15–25 mol% Yb-doped BaZrO3 could be obtained at a fairly low sintering temperature of 1500 °C, by the addition of 1.0 mol% CuO as a sintering aid. The crystal structures changed from orthorhombic (space group: Cmm2) to cubic (space group: Pm3m) by the CuO addition. The proton conductivity of thus-obtained 20 mol% Yb-doped BaZrO3 with the 1.0 mol% of CuO
ABSTRACT In the present study, (La, Sr)CoO3 material was screen-printed as a cathode and as curre... more ABSTRACT In the present study, (La, Sr)CoO3 material was screen-printed as a cathode and as current-collecting layers for planar-type low-temperature solid-oxide fuel cells (SOFCs). The compositional effects of the cathode functional and current-collecting layer on unit-cell performance were investigated using AC and DC polarization experiments. Two different cathode (La, Sr)CoO3 materials, La0.6Sr0.4CoO3 and La0.8Sr0.2CoO3, were examined, and La0.6Sr0.4CoO3 was found to be more effective for increasing the electrocatalytic activation and collection efficiency of the current produced in the cathode reaction. Furthermore, a well-designed architecture for the current-collecting layer was very effective in increasing unit-cell performance by reducing the contact resistance between SOFC cathodes and interconnects.
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Papers by HAE KOOK LEE