• Journal of Positioning, Navigation, and Timing
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• 제9권3호
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• pp.273-284
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• 2020

The performance of Global Navigation Satellite System (GNSS) chipset and Inertial Measurement Unit (IMU) sensors embedded in smartphones for location-based services (LBS) is limited due to the economic reasons for their mass production. Therefore, it is necessary to efficiently process the output data of the smartphone's embedded sensors in order to derive the optimum navigation values and, as a previous step, output performance of smartphone embedded sensors needs to be verified. This paper analyzes the navigation performance of such devices by processing the raw measurements data output from smartphones. For this, up-to-dated versions of smartphones provided by Samsung (Galaxy s10e) and Xiaomi (Mi 8) are used in the test experiment to compare their performances and characteristics. The GNSS and IMU data are extracted and saved by using an open market application software (Geo++ RINEX Logger & Mobile MATLAB), and then analyzed in post-processing manner. For GNSS chipset, data is extracted from static environments and verified the position, Carrier-to-Noise (C/N₀), Radio Frequency Interference (RFI) performance. For IMU sensor, the validity of navigation and various location-based-services is predicted by extracting, storing and analyzing data in static and dynamic environments.

• Journal of the Korean Academy of Child and Adolescent Psychiatry
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• 제29권1호
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• pp.26-30
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• 2018

Objectives: To investigate the association of problematic Internet use with oral health behaviors and oral health status in a nationally representative sample of Korean adolescents. Methods: Data from the 2010 Korea Youth Risk Behavior Web-based Survey (73238 Korean adolescents; mean age $15.06{\pm}1.75years$; age range, 12-18 years) were used. Problematic Internet use was measured using the Korean Internet Addiction Proneness Scale for Youth-Short Form. Self-report questionnaires were used to assess oral health behaviors and oral health status of adolescents. Results: Problematic Internet users were less likely to brush their teeth frequently [adjusted odds ratio (AOR)=0.59; 95% confidence interval (CI)=0.56-0.63] and at school after lunch (AOR=0.89; 95% CI=0.83-0.94) as well as more likely to perceive their oral health to be poorer (AOR=1.63, 95% CI=1.54-1.72) and experience oral symptoms (AOR=1.75, 95% CI=1.65-1.86) compared to usual Internet users. Conclusion: The study results indicate that problematic Internet use may adversely affect the oral health of Korean adolescents. Thus, oral health screening and Internet-based education are needed for adolescents experiencing problematic Internet use.

• Journal of the Korean Academy of Child and Adolescent Psychiatry
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• 제29권1호
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• pp.2-6
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• 2018

Objectives: Experiencing early childhood trauma is related to multiple psychiatric problems in adolescents and adulthood. This study aimed to examine the reliability and validity of the Korean version of the Early Trauma Inventory Self Report-Short Form (ETISR-SF) among Korean adolescents. Methods: A total of 86 adolescents aged 12-17 years (mean age $14.50{\pm}1.35years$, range 12-17) were assessed using the ETISR-SF. Other instruments, including the Children's Depression Inventory (CDI), the revised Children's Manifest Anxiety Scale (RCMAS), and the List of Threatening Experiences Questionnaire (LTE-Q), were used to assess clinical symptoms. After 2 months, 51 of the 86 participants were evaluated using the ETISR-SF to assess test-retest reliability. Results: The Cronbach's coefficient alpha for the ETISR-SF was high (0.803). Adolescents with depressive disorder showed higher ETISR-SF scores compared to healthy controls. The ETISR-SF scores were correlated higher with the scores on the LTE-Q (r=0.485) than with the scores on the CDI or RCMAS (r=0.165 and 0.347, respectively). Conclusion: The ETISR-SF was temporally stable, showing acceptable reliability (r=0.776). These findings suggest that the Korean version of the ETISR-SF appears to be a reliable and valid instrument for the measurement of reported childhood trauma.

• 아동학회지
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• 제38권2호
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• pp.191-204
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• 2017

Objective: The purpose of this study was to explore the structural relationships among duration of media use, behavior problems, and school adjustment, while accounting for gender differences. Methods: The study used 4th-wave panel data from the Korean Children and Youth Panel Study, and 2,119 first graders in elementary school were analyzed. The data were analyzed using Structural Equation Modeling. Results: The results can be summarized as follows. First, the duration of media use had a direct effect on school adjustment. Secondly, the duration of media use had an indirect effect on school adjustment through internalizing and externalizing problems. According to multigroup analysis, gender differences were found in the structural relations among variables. Conclusion: This study emphasizes the needs for media usage education to improve children's school adjustment. Furthermore, it suggests that different intervention strategies for internalizing/externalizing behavior problems are needed depending on gender.

• Journal of the Korean Academy of Child and Adolescent Psychiatry
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• 제28권3호
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• pp.168-173
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• 2017

Objectives: Adolescent depression is a complex disorder influenced by a variety of personal and familial factors. In this study, we compared the familial, cognitive, and behavioral characteristics of adolescents with and without diagnosed depression. Methods: Forty adolescents with depressive disorder were recruited from two psychiatric clinics, along with 46 healthy adolescents from a middle school and a high school. We then compared the participants' cognitive and behavioral characteristics and the child-rearing attitudes of their parents. Results: Compared to the healthy adolescents, the adolescents with depression exhibited lower self-esteem, higher emotional reappraisal, greater disruptive behavior, and lower attention. Furthermore, compared to the mothers of the healthy adolescents, the mothers of those with depression reported less affective, less autonomic, and more rejecting parenting attitudes towards their children. Conclusion: We found that attentional problems, negative parenting attitudes, negative self-cognition, and expressive suppression are all associated with adolescent depression. Parenting education and interventions appear to be needed to correct the negative cognitions of adolescents with depression.

• 대한불안의학회지
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• 제11권1호
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• pp.26-32
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• 2015

Objective : The objective of this study was to examine the mental health status and its correlates of the marriage-migrant women in Seoul, Korea. Methods : One hundred and seventy marriage-migrant women and one hundred and sixteen married Korean women were recruited from community to complete Symptom Check List-90-Revision (SCL-90-R). Marriage-migrant women were also asked for their socio-demographic factors, acculturative stress, family-relationship stress, and social support. The scores on the SCL-90-R were compared between marriage-migrant women and married Korean women, and the correlates of marriage-migrant women's mental health were investigated. Results : Compared to married Korean women, marriage-migrant women showed lower levels of mental health problems including somatization, obsession-compulsion, interpersonal sensitivity, depression, anxiety, hostility, paranoid ideation, and psychoticism. Longer length of residence in Korea, lower family income, social support, higher acculturation stress, and family relationship stress were all associated with mental health problems of marriage-migrant women Results : Our results suggest that mental health of marriage-migrant women is not necessarily bad, and several factors may affect their mental health. However, further studies are required in a larger representative sample to confirm the study findings.

• 대한불안의학회지
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• 제10권2호
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• pp.103-107
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• 2014

Objective : The objective of this study was to examine the association between childhood adversity and parenting attitude and neuroticism in adulthood. Methods : Forty nine women were recruited from community and completed Early Trauma Inventory-Short Form (ETI-SF). We compared scores on the Maternal Behavior Research Instrument (MBRI), Neuroticism of NEO Personality Inventory (NEO-PI), and Beck Depression Inventory (BDI) between women with and without childhood adversity. Results : Compared to women without childhood adversity, women with childhood adversity showed more rejecting parenting attitude and higher Depression and Self-Consciousness scores on Neuroticism domain of NEO-PI. Total ETI-SF scores and emotional abuse scores were positively correlated with rejecting attitude scores on the MBRI and BDI scores. Physical abuse scores were positively correlated with rejecting attitude scores. There were positive correlations between rejecting attitude scores on the MBRI, Neuroticism scores on the NEO-PI, and BDI scores. Conclusion : Our results suggest that childhood adversity may have a negative impact on parenting attitude and emotional state in adulthood. For girls who experienced traumatic event, early intervention is needed to prevent the development of neurotic temperament and rejecting parenting in adulthood.

• 한국가시화정보학회지
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• 제13권1호
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• pp.35-42
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• 2015

CD4+ T-cell count determines the effectiveness for antiretroviral therapy (ART) in patients with human immunodeficiency virus (HIV). Although ART slows the progression of HIV to AIDS, rapid counting of CD4+ T lymphocytes with a drop of patient's blood sample is urgently needed to ensure timely ART treatment in rural areas. Recently point-of-care CD4 testing devices have been developed by using non-flow based imaging cytometer incorporated with a sample cartridge where CD4+ T cells are reacted with fluorescently tagged specific antibodies. Here we conducted an experimental study using a conventional fluorescence microscope-based imaging system to quantitate the interaction of CD4 antibodies with CD4+ T cells at different reaction conditions. We demonstrated that a fast and affordable point-of-care CD4 test is feasible with a far less amount of antibodies and a shorter incubation time compared with a conventional sample preparation protocol for flow cytometry. We also proposed a general method to evaluate and compare the detection limit across different CD4 counting platforms by using fluorescently labelled microbeads for intensity calibration.

• 상하수도학회지
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• 제29권3호
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• pp.371-380
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• 2015

Particulate matters in a water distribution system are main causes of turbidity and discoloration of tap water. They could be removed by conventional or uni-directional flushing in a water distribution system. The behaviors and required flow velocity of particles are not well known for their flushing. A model water main and hydrant were made from transparent acrylic pipe of 30mm and 16mm in diameter, respectively. We analyzed the effect of flushing velocity, particle density, and particle diameter. We found that the existence of break-though velocities at which particles begin to be removed, and which are affected by their physical properties. The removal efficiencies seemed to be influenced by resuspension capabilities related to their upward movement from the bottom. Heavy particles like scale were hard to remove through upflow hydrant because the falling velocity, calculated using Stokes' law, was higher. Particle removal efficiencies of upward hydrant and downward drain showed minor differences. Additionally, the length between hydrant and control valve affected flushing efficiency because the particulate matters were trapped in this space by inertia and recirculating flow.

• Journal of the Korean Academy of Child and Adolescent Psychiatry
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• 제29권3호
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• pp.122-128
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• 2018

Objectives: This study evaluated the psychometric properties of the Korean version of the attention-deficit/hyperactivity disorder (ADHD) Stigma Questionnaire (ASQ) and the effect of the source of information about mental health on ADHD stigma. Methods: The Korean translation of the ASQ was prepared, and 673 participants, 20-64 years of age, completed the questionnaire using an online panel survey in South Korea. The participants also completed questionnaires detailing sociodemographic variables and the source of their mental health knowledge. Cronbach's alpha coefficient was used to explore the internal consistency of the ASQ. Factor analysis using Varimax rotation was conducted to investigate the structure of the ASQ. Results: The 26-item ASQ demonstrated excellent internal consistency (Cronbach's alpha=0.940). Factor analysis supported a three-factor structure, including Concerns with Public Attitudes, Negative Self-Image, and Disclosure Concerns. There were no significant differences in the total ASQ scores according to sociodemographic characteristics. Participants who reported the internet as their major source of information about mental health showed higher ASQ scores compared to those who used other sources for mental health information. Conclusion: The Korean translation of the ASQ has acceptable psychometric properties among Korean adults. Inaccurate information from the internet could increase the stigma toward ADHD.