• Sleep Medicine and Psychophysiology
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• v.21 no.1
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• pp.5-13
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• 2014

Objectives: Depression, sleep complaints and cognitive impairments are commonly observed in the elderly. Elderly subjects with depressive symptoms have been found to show both poor cognitive performances and sleep disturbances. However, the relationship between sleep complaints and cognitive dysfunction in elderly depression is not clear. The aim of this study is to identify the association between sleep disturbances and cognitive decline in late-life depression. Methods: A total of 282 elderly people who underwent nocturnal polysomnography in a sleep laboratory were enrolled in the study. The Korean version of the Neuropsychological Assessment Battery developed by the Consortium to Establish a Registry for Alzheimer's Disease (CERAD-K) was applied to evaluate cognitive function. Depressive symptoms were assessed with the geriatric depression scale (GDS) and subjective sleep quality was measured using the Pittsburg sleep quality index (PSQI). Results: The control group ($GDS{\leq}9$) when compared with mild ($10{\leq}GDS{\leq}16$) and severe ($17{\leq}GDS$) depression groups, had significantly different scores in the Trail making test part B (TMT-B), Benton visual retention test part A (BVRT-A), and Stroop color and word test (SCWT)(all tests p<0.05). The PSQI score, REM sleep duration, apnea-hypopnea index and oxygen desaturation index were significantly different across the three groups (all indices, p<0.05). A stepwise multiple regression model showed that educational level, age and GDS score were predictive for both TMT-B time (adjusted $R^2$=35.6%, p<0.001) and BVRT-A score (adjusted $R^2$=28.3%, p<0.001). SCWT score was predicted by educational level, age, apnea-hypopnea index (AHI) and GDS score (adjusted $R^2$=20.6%, p<0.001). Poor sleep quality and sleep structure alterations observed in depression did not have any significant effects on cognitive deterioration. Conclusion: Older adults with depressive symptoms showed mild sleep alterations and poor cognitive performances. However, we found no association between sleep disturbances (except sleep apnea) and cognitive difficulties in elderly subjects with depressive symptoms. It is possible that the impact of sleep disruptions on cognitive abilities was hindered by the confounding effect of age, education and depressive symptoms.

• Sleep Medicine and Psychophysiology
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• v.15 no.2
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• pp.82-86
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• 2008

Objectives: Obstructive sleep apnea syndrome (OSAS) not only causes respiratory disturbances during sleep but also decreases the quality of nocturnal sleep through sleep fragmentation and sleep structure change. We aimed at comparing the changes in sleep fragmentation and structure between baseline (diagnostic) nocturnal polysomnography (NPSG) and nCPAP (nasal continuous positive airway pressure) titration trial. Methods: One hundred and three patients with a baseline night of respiratory disturbance index (RDI) of 5 or greater and reduced RDI score during nCPAP titration night were retrospectively selected for the study. Sleep fragementation and sleep structure between baseline NPSG and the NPSG during nCPAP titration were compared. Sleep fragmentation index (SFI) was defined as the total number of awakenings and shifts to stage 1 sleep divided by the total sleep time in hour. SFI and other polysomnographic parameters were statistically compared between the two nights. Results: SFI during baseline NPSG and nCPAP titration nights were $29.0{\pm}13.8$ and $15.2{\pm}8.8$, respectively, indicating a significant SFI decrease during nCPAP titration (t=9.7, p<0.01). SFI showed significant negative correlations with sleep efficiency (r=-0.60, p<0.01) and total sleep time (r=-0.45, p<0.01) and a positive correlation with RDI (r=0.28, p<0.01). Conclusion: Use of nCPAP, even during the titration, significantly decreases sleep fragmentation and improves sleep structure in OSAS patients. We suggest that SFI may be utilized as a measure of assessing OSAS severity and nCPAP efficacy.

• Proceedings of the Korean Vacuum Society Conference
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• 2012.08a
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• pp.208-208
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• 2012

최근 환경문제가 많이 제기되면서 친환경적 운송수단인 자전거 개발과 관련하여 다양한 기술개발이 이루어지고 있다. 그 중 고부가가치의 서스펜션 포크의 프레임에 고기능성 표면처리로 Arc ion plating deposition system (AIPDS)을 이용하여 부식, 내마모 특성이 뛰어난 TiN 박막을 증착시켰다. AIPDS는 기존의 arc system과 달리 다원계 소재 코팅 공정조건 확립을 위하여 chamber wall에 2개의 rectangular type sputter source를 장착하고 소재의 pre-treatment 용 linear type ion source를 설치하였다. 장비의 Chamber 중앙에는 pipe형 arc cathode를 설치하였으며, 그 주위를 anode 역할을 하는 copper 코일로 감아 이는 발생한 arc를 target인 cathode 축을 중심으로 방향성을 가지고 회전하여 진행 할 수 있도록 유도 하였다. 이 시스템에서 증착된 TiN 박막은 bias 전압 변화에 따른 박막의 구조 및 물성을 평가하였다. XRD 장비를 통하여 TiN 박막의 상분석을 진행하였고, 마모테스터, 원자현미경, 마이크로 비커스 경도기 등을 이용하여 기계적 특성을 평가하였다.

• Proceedings of the KSLP Conference
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• 1997.11a
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• pp.259-259
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• 1997

폐쇄성 수면무호흡의 치료를 목적으로 한 구개수구개인두성형술 이후의 음성변화 유무를 파악하여, 성악가 등의 전문적인 음성사용자에게 상기한 수술을 결정함에 있어서 가능한 guideline을 제시하여 보고자 하였다. 수면다원검사상 폐쇄성 수면무호흡증으로 진단된 성인남자 20명을 대상으로 수술전후의 음성변화에 대한 설문조사를 하였고, 수술전, 수술후 1개월에 각각 /아/, /이/, /우/ 모음의 제1, 2, 3 음향대를 비교하였으며, 표준 비음비율이 각기 다른 세가지 문장을 이용하여 수술전후의 비음비율의 변화를 측정하였다. 환자 자신은 수술전후의 음성이나 음색의 변화를 느낄 수 없었고, 비음비율의 변화나 모음의 음형대에 대부분은 변화가 없었지만, /우/ 음의 제3음형대 특성에 변화가 있음을 관찰하였고, 구인두가 중요한 역할을 담당할 수 있는 특정언어의 일부 발음이나 vibrato, singer's formant등의 변화유무에 대한 연구가 없는 점을 감안한다면, 성악가를 비롯한 전문적 음성사용자에？서는 구개수 구개인두성형수술을 결정함에 있어 신중을 기하여야 할 것으로 사료되었다.

• Korean Journal of Child Studies
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• v.28 no.2
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• pp.55-70
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• 2007

This study used path analysis to investigate causal effects of creative home environment and emotional and cognitive variables on children's creative thinking and characteristics. the subjects were 233 5- and 6-year-old children, their mothers and teachers in the City of Taegu and Kyungpook Province. Major results were that (1) creative home environment directly affected children's creative thinking, creative characteristics and motivation. (2) Children's motivation directly affected children's creative characteristics. (3) Children's temperament directly affected motivation and indirectly affected children's creative characteristics through motivation. (4) Children's intelligence directly affected knowledge, and indirectly affected children's creative thinking through knowledge.

• Proceedings of the Korean Vacuum Society Conference
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• 2012.02a
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• pp.423-423
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• 2012

ZnO, SnO2, In2O3:Sn와 같은 투명하고 전도성이 있는 박막은 panel display, 전자발광소자, 박막트랜지스터, 태양전지 등의 전극물질로서 폭넓게 사용되고 있다. 이러한 전극 물질을 이용하는 광전자소자의 성능을 개선하기 위해서는 가시광선영역에서 광투과율이 높고, 전기전도도가 좋아야 한다. 최근 ZnO, SnO2, In2O3, MgO, Ga2O3 등으로 이루어진 3원 또는 다원화합물로 제조된 산화물 박막이 새로운 투명한 전도성 박막으로 많은 관심을 끌고 있다. 본 연구에서는 Ga2O3 박막을 radio-frequency magnetron sputtering 방법을 이용하여 증착하였다. 기존에 사용되던 ceramic target을 개선하여 powder target을 사용하였다. 반응가스는 순수하게 Ar 가스만 사용하였고, Sapphire(0001) 기판을 사용하였다. 초기에는 flat한 layered 구조로 증착이 이루어졌으나, 증착시간이 20분이 지나면서부터는 밤송이 모양을 가지는 나노구조체가 생성되기 시작하였고, 이후 나노 밤송이의 밀도가 점차 증가하였다. Ga2O3 나노 밤송이의 특성에 대하여 발표할 예정이다.

• Sleep Medicine and Psychophysiology
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• v.19 no.2
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• pp.59-62
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• 2012

Borderline personality disorder (BPD) is characterized by identity and interpersonal problem, affective dysregulation and pervasive severe impulsivity. Although sleep disturbances are not primary symptoms of BPD, they are important aspects of this disorder. However, clinicians and researchers did not give much attention to the sleep symptoms of BPD yet. Measured by nocturnal polysomnography, increased sleep latency as well as reduced total sleep time and sleep efficiency, and 'depression-like' REM abnormalities (i.e., reduced REM latency and increased REM density) are found in BPD patients. Co-morbid sleep disorders such as chronic insomnia, nightmare disorder or circadian rhythm sleep disorder associated with BPD have been reported. Clinicians should focus on the sleep complaints of BPD patients, and carefully manage such symptoms with sleep hygiene education, cognitive psychotherapy or light therapy.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.7
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• pp.475-480
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• 2016

Abandoned empty houses are largely left neglected as unused space, due to the slowdown in the real estate market that has resulted from the declination of urban functions. This research aims to analyze the characteristics of the City of Detroit's policies and regeneration efforts regarding abandoned houses, based on the perspective of unused space. This is expected to provide the baseline data for similar efforts to be applied to abandoned houses in the Korean context, thus preventing the decline of urbanism by adopting relevant policies and regeneration efforts. Some of the key features of the City of Detroit's regeneration efforts are: 1) the active participation of residents and open-data policies, 2) the diversification of regeneration strategies depending on the potential of the unused space, and 3) securing differential plurality of the regeneration processes.

• Korea journal of population studies
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• v.24 no.2
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• pp.235-253
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• 2001

As we are entering the information society, there are increasing concerns about information gaps which are believed to create serious obstacles to social integration and development. Previous studies on the information gaps in Korea, despite their contributions to our understanding of the issue, appear to be descriptive. This study attempts to analyze the relative importance of residential area, gender, age education, and household income for information gaps and their changes in recent years. Based on the data from two surveys conducted by the Information Culture Center, the study run multivariate logit model analysis of the sue of computer and internet. The result shows that all the variables except residential area have influences on the use of computer and internet. In terms of time change, gender-based difference in the use of digital media has decreased between 1998 and 2000 while the differences by all the other variables have remained constant or increased.

• Korean Journal of Head & Neck Oncology
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• v.21 no.2
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• pp.121-125
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• 2005

Objectives: To investigate the role of MMP-2 and TIMP-2 in the invasion and metastasis of thyroid papillary microcarcinomas. Materials and Methods: We performed immunohistochemical study on MMP-2 and its tissue inhibitor (TIMP-2) using tissue microarrays containing 2 cores of 40 microPTC and 8 non-neoplastic thyroid tissue. The expression intensity was semiquantitatively scored as -, ${\pm}$, +1, +2, and +3. Results: Both MMP-2 and TIMP-2 expression was observed in all tumors(100%) and in 1 of 8 non-neoplastic tissue(12.5%), and the positive staining was restricted to the epithelial cells. In 17 and 23 tumors with or without extrathyroid invasion, respectively, 8(47%) and 10(43%) cases showed moderate to strong(+23) positivity for MMP-2. TIMP-2 expression was moderate to strong in 13 cases(76%) and 16 cases(70%) in each group. In multifocal and solitary tumors, 3 of 6(50%) and 11 of 21(52%) cases showed moderate to strong MMP-2 expression, and 5/6(83%) and 15/21(71%) showed moderate to strong TIMP-2 expression. Conclusion: There is no relationship between MMP-2 or TIMP-2 expression and extrathyroid invasion or tumor multifocality in papillary microcarcinoma of the thyroid gland.