• Journal of Ocean Engineering and Technology
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• v.11 no.3
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• pp.144-152
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• 1997

본 논문에서는 1년생 빙맥에 의하여 해양구조물에 작용하는 하중을 추정할 수 있는 모델을 제시하였다. 1년생 빙맥을 수면하부(keel), 수면상부(sail), 경화층(consolidated layer)의 3부분으로 나누어 각 부분에 의한 하중을 추정할 수 있는 방법을 논의하였다. 수면하부는 얼음조각(ice rubble)이 층으로 쌓여져 형성된 것이므로 수면하부에 의한 하중추정을 할 때 얼음조각을 선형 Mohr-Coulomb재료로 생각하여 토질역학(soil mechanics)의 이론을 사용하였다. 수면상부에 의한 하중도 토질역학 이론을 이용하여 추정하였으며 경화층에 의한 하중은 Korzhavin식을 이용하여 추정하였다. 제시한 모델을 이용하여 빙맥하중 추정에 미치는 인자들의 영향을 검토하였다.

• The Journal of Engineering Geology
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• v.19 no.2
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• pp.217-225
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• 2009

A series of model borehole experiments and analyses for density compensation were performed to achieve the effective density correction of gamma-gamma log obtained from PVC cased boreholes. A follow-up survey was made for clarifying the variation property of detector responses depending on casing types, the presence of borehole fluid, and the degree of separation between probe and borehole wall. A special emphasis was placed on the comparison of gamma responses obtained from above and below ground water tables. Finally, we could quantify the detector responses as a function of separation between the probe and borehole wall, construct standoff compensation charts, and the limitations of the compensation have been discussed for the environments of both above and below ground water tables.

• Proceedings of the Korea Water Resources Association Conference
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• 2004.05b
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• pp.1173-1177
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• 2004

현재 다양한 분야에서 널리 사용되고 있는 지하투과레이더(Ground Penetrating Radar, GPR)를 이용하여 지하수면 및 함수량을 추정하였다. 비피압대수층 내에서의 얕은 포화대(saturated zone) 깊이을 산정하는 연구(livari and Doolittle, 1994, van Overmeeren, 1994)와 포화대 상부 습윤대(wetting fronts)의 거동를 조사한 연구(Vellidis et al, 1990) 등에 활용된 바 있는 GPR 기숙을 바탕으로 비피압대수층의 통기대와 포화대 내의 함수량 및 지하수면 추정을 위한 기초 실험을 수행하였다. 지하수면 및 함수량의 현장 적용성을 검증하기 위해서는 시간과 경제적인 면에서 비효율적인 점을 고려하여 사질토로 구성된 실험용 토조를 제작하여 건조시 획득된 GPR 자료, 지하수면의 변화에 따른 GPR 이미지를 비교하여 그 적용성을 검토하고 시${\cdot}$공간적 지하수면의 정확한 추정을 위해서 삼차원으로 비교${\cdot}$검토할 수 있도록 하였으며, GPR 자료의 정확성을 검증하기 위해서 토조 하부에 액주계(piezometer)를 설치하였다. 본 연구에서 적용된 GPR 실험은 획득된 이미지의 해석에 다소 어려움이 있지만 토양을 교란시키지 않고 비교적 간편하게 함수랑 및 지하수면의 위치를 파악하는데 매우 효과적이며, 추가적으로 GPR을 이용한 다양한 실험이 수행된다면 GPR 기술은 향후 기존 방법에서 쉽게 판단하기 어려운 시${\cdot}$공간적인 함수량 및 지하수의 분포 특성을 효율적으로 파악하는데 매우 큰 도움을 줄 수 있을 것이다.

• Journal of Oral Medicine and Pain
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• v.35 no.3
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• pp.193-202
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• 2010

The purpose of this study was to determine the sites of narrowing/obstruction and to measure the regional severity of narrowing through the evaluation of dynamic changes in upper-airway of healthy subjects. The selected 9 subjects were proved not to have any sleep-related disorder such as snoring or obstructive sleep apnea through clinical examination, radiological examination, sleep study with a portable recording system. Afterward, the Electron Beam Tomography was performed during the waking and sleeping state of subjects, with their mandible in resting and protruded position. Intravenous injection of Dormicum$^{(R)}$ was used for the induction of sleep. The maximum and minimum cross-sectional areas at each airway level during tidal ventilation were measured and the Collapsibility Index for each level of cross-section was also computed. In a comparison with results under variable conditions, the result was showed that the significant difference between each airway level divided with upper, middle, lower region of upper airway is not observed in the average minimum cross-sectional areas and Collapsibility Index. The significant difference only between in wake and sleep state was observed in the average minimum cross-sectional area at the lower region. Also, in wake state, the significant difference between resting and protrusive position of mandible for the average minimum was also observed in cross-sectional area at middle region. In sleep state, no significant difference between resting and protrusive position of mandible was observed in cross-sectional area and the Collapsibility Index.

• 한국노년학
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• v.28 no.4
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• pp.1041-1054
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• 2008

This study aimed to identify the severity and types of prostate symptom, to identify the relationship of prostate symptom, sleep quality and quality of life of the elderly in korea, so to provide basic data for developing nursing interventions for the elderly's prostate symptom management. This study used a descriptive correlational research design. The subjects of this study were 100 elderly men over 65yr in an urban city. Data were collected through personal interviews using questionnaires from September 2006 to March 2007. The IPPS, PSQI and SF-36-K were administered. The collected data were analyzed by descriptive statistics and Pearson's correlation. The major findings of this study were as follows: 1) 44% of the participants have moderate to severe Prostate symptom(IPSS>7). 2) Prostate symptom has positive relationship with sleep quality(r=.272, p=.006) and negative relationship with health related quality of life(r=-.197, p=.049). The results of this study indicate that prostate symptom is related to sleep quality and quality of life. So it is necessary to give information to the elderly about the effective coping method of prostate symptom and about the life style which have positive effect to prostate symptom.

• Journal of Convergence for Information Technology
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• v.9 no.10
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• pp.213-219
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• 2019

This study is a descriptive research on the relationship among smartphone addiction, lack of sleep and sleeping hours of undergraduates. The subjects include 280 students enrolled in G university and data were collected from Sep. 6 to Oct. 10, 2018. On average, each score of smartphone addiction, sleeping hours and lack of sleep was $34.79{\pm}7.6$, $6.43{\pm}1.34$ and $10.14{\pm}3.14$ respectively. Smartphone addition had a significantly positive correlation with lack of sleep(r=.277, p<0.01) and a positive correlation with its sub-areas, such as disability in daily life(r=.269, p<0.01), virtual(r=.151, p<0.01), withdrawal(r=.303, p<0.01), tolerance(r=.184, p<0.01). The education and counselling for preventing undergraduates from smartphone addiction and further studies on them are required.

• 한국노년학
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• v.38 no.4
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• pp.853-869
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• 2018

This study aimed to investigate variables affecting subjective memory impairment in the elderly with benign prostatic hyperplasia. We used 179 survey data collected from the urology department of two metropolitan general hospitals. The subjects were patients with benign prostatic hyperplasia. T-test, one-way analysis of variance, and $Scheff{\acute{e}}^{\prime}s$ test were performed to identify differences among variables. Pearson's correlation-coefficient and stepwise multiple regression were used to identify variables that affect subjective memory impairment. This study revealed that lower urinary tract symptom and activities of daily living were statistically significant variables, with an explanatory power of 30.0%. The lower urinary tract symptom was due to the benign prostatic hyperplasia increasing the risk of subjective memory impairment. Treatment of the lower urinary tract symptom was delayed because as the elderly got older, they increasingly recognized benign prostatic hyperplasia as a reasonable symptom. Timely intervention and early screening are necessary to prevent lower urinary tract symptom. Finally, programs to reduce the incidence of lower urinary tract symptom and educate nurses to assess, evaluate, perform intervention for subjective memory impairment should be developed.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2011.06a
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• pp.55-57
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• 2011

경인 아라뱃길이 2011년 10월 개장을 앞두고 있다. 경인 아라뱃길이 시작되는 경인항 서해갑문 입출거시 예선사용기준에 대한 연구는 선박운항의 경제성 측면에서 매우 중요한 의미를 지닌다고 할 수 있다. 통상 선박의 크기(톤수)에 따른 예선의 소요마력 및 사용 척수는 대상선박의 크기, 모양, 접근수로, 부두시설의 위치 및 종류, 기타 환경조건 등의 영향을 받으며, 선체에 작용하는 수면상부의 풍압력과 수면하부의 유압력을 고려하여 규정하고 있다. 따라서 본 연구에서는 국내외 예선 규정 및 대상선박에 대한 예선 조종시뮬레이션을 통하여 경인항 서해갑문 입출거시 사용되는 예선의 기준을 설정하였다.

• Journal of Korean Academic Society of Home Health Care Nursing
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• v.25 no.1
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• pp.58-66
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• 2018

Purpose: The purpose of this study was to find out lower urinary tract symptoms, daily life inconvenience, and sleep quality in elderly community woman. Methods: Participants were 140 elderly women. Data collection was conducted from September 1 to October 30, 2017. Data were analyzed using descriptive statistics and t-test with the SPSS program. Results: The rate of urge incontinence was 25.0%, stress incontinence 36.4%, unexplained incontinence 15.7%, and nocturnal incontinence 9.3%. Those participants with urge incontinence presented significantly higher daily life inconvenience scores; urge incontinence, stress incontinence, and unexplained incontinence were significantly associated with lower sleep quality scores. Furthermore, frequent urination, nocturia, and incomplete emptying were significantly higher daily life inconvenience scores; and frequent urination, nocturia, hesitancy, straining, intermittent stream, burning, incomplete emptying, bladder pain, and abnormal strength of stream were significantly related to lower sleep quality scores. Conclusion: It is necessary to develop intervention strategies considering incontinence and urination symptoms to reduce daily life inconvenience caused by lower urinary tract symptoms and improve sleep quality in elderly women.

• Sleep Medicine and Psychophysiology
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• v.26 no.1
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• pp.16-22
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• 2019

Objectives: The objective of this study was to investigate the correlation between insufficient sleep and visuospatial memory in adolescents using a computerized neurocognitive function test. Methods: A total of 103 high school students (26 males and 77 females; mean age $17.11{\pm}8.50years$) without a serious psychiatric problem was recruited. All subjects were requested to complete a self-report questionnaire about weekday total sleep time and weekend total sleep time. The epworth sleepiness scale (ESS) and the beck depression inventory (BDI) were administered to measure daytime sleepiness and symptoms of depression. Seven subsets of the Cambridge Neuropsychological test automated battery were examined to assess visuospatial memory. Results: After controlling for age, sex, ESS, and BDI, longer weekend total sleep time was correlated with poor performance on delayed matching to sample (r = -0.312, p = 0.002) and immediate recall on pattern recognition memory (r = -0.225, p = 0.025). Increased weekend catch-up sleep time was correlated with poor performance of delayed matching to sample (r = -0.236, p = 0.018), immediate recall on pattern recognition memory (r = -0.220, p = 0.029), and delayed recall on pattern recognition memory (r = -0.211, p = 0.036) after controlling for age, sex, ESS, and BDI. Conclusion: This study showed that increased weekend catch-up sleep time reflecting insufficient weekday sleep were associated with poor performance in delayed recall tasks of visual memory. This finding suggests that insufficient sleep during adolescence might produce a decline of visuospatial memory.