AN IN-SITU YOUNG'S MODULUS MEASUREMENT TECHNIQUE FOR NUCLEAR POWER PLANTS USING TIME-FREQUENCY ANALYSIS

Choi, Young-Chul,Yoon, Doo-Byung,Park, Jin-Ho,Kwon, Hyun-Sang Korean Nuclear Society 2009 Nuclear Engineering and Technology Vol.41 No.3

Elastic wave is one of the most useful tools for non-destructive tests in nuclear power plants. Since the elastic properties are indispensable for analyzing the behaviors of elastic waves, they should be predetermined within an acceptable accuracy. Nuclear power plants are exposed to harsh environmental conditions and hence the structures are degraded. It means that the Young's modulus becomes unreliable and in-situ measurement of Young's modulus is required from an engineering point of view. Young's modulus is estimated from the group velocity of propagating waves. Because the flexural wave of a plate is inherently dispersive, the group velocity is not clearly evaluated in temporal signal analysis. In order to overcome such ambiguity in estimation of group velocity, Wigner-Ville distribution as the time-frequency analysis technique was proposed and utilized. To verify the proposed method, experiments for steel and acryl plates were performed with accelerometers. The results show good estimation of the Young's modulus of two plates.

Analysis and Evaluation of Capillary Passive Valves in Microfluidic Systems Using a Centrifugal Force

Cho, Han-Sang,Kim, Ho-Young,Kang, Ji-Yoon,Kwak, Seung-Min,Kim, Tae-Song The Korean Institute of Electrical Engineers 2004 KIEE International Transactions on Electrophysics Vol.4C No.4

This work reports the theoretical and experimental investigations of capillary bust valves to regulate liquid flow in microchannels. The theoretical analysis uses the Young-Laplace equation and geometrical considerations to predict the pressure at the edge of the valve opening. Numerical simulations are employed to calculate the meniscus shape evolution while the interface is pinned at the valve edge. Microchannels and valves are fabricated using soft lithography. A wafer-rotating system, which can adjust the driving pressure by rotational speed, induces a liquid flow. Experimentally measured valve-bursting pressure agrees with theoretical predictions.

Contribution of stress and coping strategies to problematic Internet use in patients with schizophrenia spectrum disorders

Lee, Ju-Yeon,Chung, Young-Chul,Song, Je-Heon,Lee, Yo-Han,Kim, Jae-Min,Shin, Il-Seon,Yoon, Jin-Sang,Kim, Sung-Wan Elsevier 2018 Comprehensive psychiatry Vol.87 No.-

<P><B>Abstract</B></P> <P><B>Introduction</B></P> <P>Internet use is already high and increasing rapidly among people with psychotic disorders, but there have been few studies on problematic Internet use (PIU) among patients with schizophrenia spectrum disorders. This study aimed to measure the prevalence of PIU and identify the factors associated with PIU among patients with schizophrenia spectrum disorders.</P> <P><B>Methods</B></P> <P>A cross-sectional survey was performed that included 368 outpatients with schizophrenia spectrum disorders: 317 with schizophrenia, 22 with schizoaffective disorder, 9 with schizophreniform disorder, and 20 with other schizophrenia spectrum and psychotic disorders. The severity of psychotic symptoms and levels of personal and social functioning were assessed by the Clinician-rated Dimensions of Psychosis Symptom Severity (CRDPSS) scale and the Personal and Social Performance (PSP) scale, respectively. PIU was evaluated using Young's Internet Addiction Test (IAT). Additionally, the Hospital Anxiety and Depression Scale (HADS), Perceived Stress Scale (PSS), Rosenberg Selfesteem Scale (RSES), and Brief Coping Orientation to Problems Experienced (COPE) Inventory were administered.</P> <P><B>Results</B></P> <P>PIU was identified in 81 (22.0%) of the 368 patients with schizophrenia spectrum disorders. Subjects with PIU were significantly younger and more likely to be male. Scores on the HADS, PSS, and dysfunctional coping dimension of the Brief COPE Inventory were significantly higher, and RSES scores were significantly lower, in the PIU group. Logistic regression analysis indicated that PIU in patients was significantly associated with scores on the PSS and dysfunctional coping dimension of the Brief COPE Inventory.</P> <P><B>Conclusions</B></P> <P>Patients with schizophrenia spectrum disorders and PIU were significantly more likely to have high levels of perceived stress and dysfunctional coping strategies. Patients with schizophrenia spectrum disorders who also engage in PIU may benefit from interventions that help them to develop appropriate skills for coping with stress.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Patients with schizophrenia spectrum disorders showed a high prevalence (22.0%) of problematic internet use (PIU). </LI> <LI> High levels of perceived stress rather than psychopathology itself contributes to the development of PIU in stabilized patients with schizophrenia. </LI> <LI> Our results indicate that managing stress and developing coping strategies are important for the prevention of PIU among this group of patients. </LI> </UL> </P>

Effect of gel spinning accompanied with cross-linking using boric acid on the structure and properties of high-molecular-weight poly(vinyl alcohol) fiber

Jo, Yong Gu,Shin, Eun Joo,Lee, Young Jae,Yoon, Won Sik,Han, Sung Soo,Lee, Yang Hun,Lee, Yong Rok,Noh, Seok Kyun,Gal, Yeong Soon,Lyoo, Won Seok Wiley Subscription Services, Inc., A Wiley Company 2009 Journal of applied polymer science Vol.113 No.3

<P>To enhance the thermal stability of poly(vinyl alcohol) (PVA) fiber, the fiber was prepared from the gel spinning of high molecular weight (HMW) PVA by using dimethyl sulfoxide/water (8/2, v/v) as a solvent, accompanied with the cross-link by boric acid (B-PVA). In addition, the structure and properties of the B-PVA fiber were compared with those of the HMW PVA fiber obtained by using the same spinning system without cross-linking (NB-PVA). Through a series of experiments, it turned out that cross-linking actualized by an optimum amount of boric acid (0.3 wt % based on PVA) and zone drawing caused significant changes in the properties of HMW PVA gel fiber. That is, cross-linking increased thermal degradation temperatures at each degradation step and amounts of final residues, resulting in improving thermal properties of the PVA fiber. On the contrary, it was found that in the case of the B-PVA fiber, some broadening of the original PVA unit cell occurred, which was identified by the peak shift to lower angle in X-ray diffractogram. The tensile strength and Young's modulus of B-PVA fiber with draw ratio of 15 are 23.1 and 308.3 g/d, respectively. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009</P>

Effect of DREAMMO<SUP>®</SUP> Scalp Lotion on Hair Growth Promotion in an Alopecia Model of C57BL/6 Mice

Seung Ho Lee,Hwa Jeung Lee,In Jeoung Baek,Jung Min Yon,Sang Yoon Nam,Beom Jun Lee,Young Won Yun,Yun-Bae Kim,Seock Yeon Hwang,Jin Tae Hong 한국실험동물학회 2006 Laboratory Animal Research Vol.22 No.1

Scalp hair loss has increased recently in young-aged people as well as middle-aged people, and although there are no serious in health problems, scalp hair loss may significantly affect a variety of psychological and social experiences and the individual's quality of life. DREAMMO scalp lotion is composed of several plant extracts which are known to be used as oriental medicine to prevent hair loss or promote hair growth in alopecia. This study was carried out to investigate the effect of DREAMMO scalp lotion on hair growth in an alopecia model of C57BL/6 mice. Mice were divided into three experimental groups including control, DREAMMO scalp lotion and 3% Minoxidil (MXD). The test compounds were topically treated with 0.2 ㎖ per mouse per day for 4 weeks. The hair growth was determined photographically and histologically in an alopecia model of C57BL/6 mice. After 3-4 weeks, DREAMMO scalp lotion significantly increased hair growth compared to the controls in the dorsal skin of C57BL/6 mice. DREAMMO scalp lotion also promoted the elongation of hair follicles than the controls. These results suggest that DREAMMO scalp lotion has a hair growth activity and can be useful for the treatment of alopecia.

마이크로파에 의한 생분해성 β-TCP/PLGA 복합체의 제조시 β-TCP 첨가량에 따른 영향

진형호,민상호,박홍채,윤석영,Jin, Hyeong-Ho,Min, Sang-Ho,Park, Hong-Chae,Yoon, Seog-Young 한국재료학회 2006 한국재료학회지 Vol.16 No.1

Biodegradable $\beta$-tricalcium phosphate ( $\beta$-TCP)/poly(lactide-co-glycolide) (PLGA) composites were synthesized by in-situ polymerization with microwave energy. The influence of the $\beta$-TCP content in $\beta$-TCP/PLGA composites on the molecular weight, crystallinity, microstructure and mechanical properties was investigated. As the molecular weight of composites decreased, the $\beta$-TCP content increased up to 10 wt.%, while the excess addition of the $\beta$-TCP content above 10 wt.% the molecular weight increased with increasing of the $\beta$-TCP content. This behavior would be due to the superheating effect or nonthermal effect induced by microwave energy. It was found that the bending strength and Young's modulus of the $\beta$-TCP/PLGA composites was proportional to the molecular weight of PLGA. The bending strength of the $\beta$-TCP/PLGA composites ranged from 18 to 38 MPa, while Young's modulus was in the range from 2 to 6 GPa.

Nanogenerators: Fully Rollable Transparent Nanogenerators Based on Graphene Electrodes (Adv. Mater. 19/2010)

Choi, Dukhyun,Choi, Min-Yeol,Choi, Won Mook,Shin, Hyeon-Jin,Park, Hyun-Kyu,Seo, Ju-Seok,Park, Jongbong,Yoon, Seon-Mi,Chae, Seung Jin,Lee, Young Hee,Kim, Sang-Woo,Choi, Jae-Young,Lee, Sang Yoon,Kim, Jo WILEY-VCH Verlag 2010 ADVANCED MATERIALS Vol.22 No.19

<B>Graphic Abstract</B> <P>The cover shows an image of fully rollable transparent nanogenerators synthesized using chemical vapor deposition grown large-scale graphene sheets as transparent electrodes and piezoelectric ZnO nanorod arrays. Sang-Woo Kim, Jae-Young Choi, and co-workers report on p. 2187 the electrical and structural stability of the nanogenerators, with excellent charge scavenging performance under external mechanical loads such as bending and rolling. This study shows that graphene-based nanogenerators are very promising for self-powered rollable transparent device applications. <img src='wiley_img_2010/09359648-2010-22-19-ADMA201090066-content.gif' alt='wiley_img_2010/09359648-2010-22-19-ADMA201090066-content'> </P>

한국인 인슐린 비의존형 당뇨병 및 이차성 당뇨병 환자에서 글루코키나제 유전자 변이

남재현(Jae Hyun Nam),이현철(Hyun Chul Lee),김연의(Youn Euy Kim),권석호(Suk Ho Kwon),윤용석(Yong Suk Yoon),박석원(Suk Won Park),원영준(Young Jun Won),차봉수(Bong Su Cha),송영득(Young Duk Song),이은직(Eun Jig Lee),임승길(Sung Kil Lim) 대한내과학회 1998 대한내과학회지 Vol.54 No.6

N/A Objectives: Mutations in the glucokinase (GCK) gene are considered a possible cause of maturity-onset diabetes of the young. The purpose of this study was to evaluate the contribution of this gene to the development of non insulin dependent diabetes mellitus (NIDDM), gestational diabetes mellitus (GDM) and post-renal transplantation diabetes mellitus (PTDM). Method: Identification of GCK mutation was attempted on 39 NIDDM patients, 2 GDM patients and 58 selected renal allograft recipients with PTDM and 45 normal controls. The exons in the GCK gene were examined by polymerase chain reaction (PCR), followed by analysis of single-stranded DNA conformational polymorphism (SSCP). The abnormal bands were also confirmed by DNA sequencing analysis. The exons of affected family members were also investigated for mutations of the GCK gene. Results: Two of the 58 PTDM patients (3.4%) were found to have CKK mutations. One had the mutation on exon 5 and the other on intron 7. One control subject had the mutation on intmn 9. The mutation of exon 5 was identified as a substitution of CCT (proline) for CTT (leucine) at codon 164, which has not ever reported before. The family members of the PFDM patient with mutation of exon 5 were analyzed by PCR followed by SSCP, and two of them revealed the same mutation. The abnormal band on the SSCP analysis of exon 7 was identified as the insertion of base C/T at the 39th nucleotide in intron 7. Two family members of this patients also had same band on SSCP. The one mutation of 45 normal controls was CT located at the 8th nucleotide in intron 9, which was a common polymorphism. Conclusion: We found GCK mutations in subjects with PTDM and we speculate that these mutations may be one of the contributing cause of PTDM.

유아음악교육에 대한 유아교사의 인식 및 운영실태

김성윤(Sung Yoon Kim),김권일(Kwon Il Kim),김영옥(Young Ok Kim) 한국열린유아교육학회 2015 열린유아교육연구 Vol.20 No.1

본 연구는 유아교육기관에서 이루어지는 유아음악교육에 대한 유아교사의 인식과 운영실태를 분석하고자 실시하였다. 선행연구를 통해 연구도구인 설문지를 구성하였 으며 유아교사 190명을 무선 표집 하여 연구자료를 수집하였다. 수집된 자료는 SPSS 18.0을 이용하여 빈도와 백분율, 독립표본 t-검증, 일원변량분석(One-way ANOVA)을 통하여 분석하였고, 집단 간의 차이 분석은 Duncan 검증을 통해 사후 분석 하였다. 연구결과는 첫째, 유아교사들은 유아음악교육에 대하여 전반적으로 높 은 인식을 가지고 있었다. 둘째, 유아음악교육에 대한 교사변인 간 인식은 차이가 있 는 것으로 나타났다. 셋째, 교사용 지도서를 많이 참고하였고, 음악교육에서는 신체 표현을 가장 많이 활용하였으며, 주 2~3회 음악활동을 진행하는 것으로 나타났다. 넷째, 유아음악교육에 대한 교사변인 간 운영실태는 차이가 있는 것으로 나타났으며 실태의 개선을 위한 다각적 접근을 논하였다. This study was to examines the actual situations and recognition of teachers of music education for young children in children education institutes. It sheds light on young children``s music education as well as provides effective operating information. Based on advanced research, a questionnaire is designed as a measure to examine actual situations and recognition of 190 teachers, Chosen by random sampling, on music education for young children. The questionnaire survey is carried out and data collected on the recognition of teachers of music education for young children by the teacher``s background and on actual situations of operating music education. The data are analyzed by frequency and percentage, t-test using SPSS 18.0 and one-way ANOVA. Duncan test is used as a post test when analyzing differences between groups. The results of this study are as follows. First, recognition of teachers on music education for young children was statistically significant and it was statistically meaningful between teacher variables. Second, recognition of teachers of music education for young children was statistically significant and it was statistically meaningful between teacher variables. Third, in actual situations of music education, music is most often used in physical expression activities: teachers usually refer to guidebooks, and music education occurs two to three times a week. Fourth, the actual situations of teachers of music education for young children was statistically significant and they were statistically meaningful between teacher variables.

A Phase 3 Study of TAF Compared with TDF in Patients with HBeAg-Positive CHB: Week48 Efficacy Results of Korea Patients

( Young-Suk Lim ),( Hyung Joon Kim ),( Ki Tae Yoon ),( Won Young Tak ),( Jae-Seok Hwang ),( Sang Hoon Ahn ),( Kwan Soo Byun ),( Seung Woon Paik ),( Sook-Hyang Jeong ),( Yoon Jun Kim ),( So Young Kwon 대한간학회 2017 춘·추계 학술대회 (KASL) Vol.2017 No.1

Aims: In this randomized, double-blind study in HBeAg-positive patients, the efficacy of TAF was demonstrated to be non-inferior to that of TDF at Week48 in the proportion with HBV DNA<29 IU/mL with improved bone and renal effects. Here we present the subgroup efficacy analysis of Korean patients in the study. Methods: In this study, patients with HBeAg-positive CHB were randomized 2:1 to TAF 25mg or TDF 30mg, with matching placebo, and treated for 96weeks. The primary efficacy analysis was the percent of patients with HBV DNA<29 IU/mL at Week48. The results of primary efficacy analysis of Korean patients were separately analyzed. Results: 873 patients were randomized and treated, including 173 subjects(20%) in the Korea population (TAF 120 subjects; TDF 53 subjects). Comparison across the 3 subject populations (Korea, nonKorea, and overall) showed that Korea subjects were older, a higher proportion were female and ≥ 50 years of age at baseline, a lower mean baseline HBV DNA level, and similar portion of treatment-experienced subjects. Nearly all were genotype C. Key efficacy end points are summarized in the Table. The percentages of Korean subjects with HBV DNA levels <29 IU/mL at Week48 were higher than the non-Korea population (74% with TAF and 76% with TDF). Smaller percentage of Korean patients treated with TAF achieved normalization of serum ALT values and HBeAg seroconversion rates were similar(TAF 10%; TDF 9%). The rates of treatment discontinuations and serious AEs were low and similar, consistent with overall population. Korea subjects treated with TAF showed smaller declines in hip and spine BMD and smaller changes in CrCl at Week48 compare with TDF arm. No viral resistance was observed. Conclusions: Compared to TDF 300mg, the efficacy of TAF 25mg in patients with HBeAg-positive CHB was non-inferior. Week48 efficacy results of Korean population were consistent with those of the nonKorea and overall populations.