• Journal of Physiology & Pathology in Korean Medicine
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• v.32 no.6
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• pp.403-410
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• 2018

Lifestyle of adolescents cause a lot of health effects in the future. Therefore, in Korea, school health law was enacted and relevant business such as school education program is being carried out. This study was conducted to recognize symptom according to grade. A survey of youth health status was conducted at 19 middle and high schools in Seongnam city from May 2015 to December 2015. The survey made up of 14 questions which was about the health status satisfaction on the adolescent was conducted to investigate frequency by year and the respective health status of 6 grades. A total of 9,584 students responded to the survey, 58.22% answered that they were not free of constipation. 25.69% of respondents had no symptoms of headache, consequently over 70% of respondents had headache. 57.06% of respondents had no symptoms of low back pain and 34.7% had no symptoms of neck & shoulder pain, therefore over 50% of respondents had muscular skeletal symptoms. In menstrual history, only 17.95% of respondents said their period was regular and painless. In respiratory history, except cold, no nasal drop & obstruction has appeared in the group of 54.02%. And 62.97% of respondents had persistent cough usually with cold and 23.41% had cough with cold breeze even if not catch cold. In the third grade of high school students, there were many complaints of pain in various parts such as headache, back pain and shoulder pain, neck pain and menstrual pain, and there was a high rate of complaints of digestive system symptom and defecation symptom. More than half of respondent had constipation discomfort, headache and musculo-skeletal symptoms, menstrual problems and cough. In the third grade of high school students, the rate of complaints of pain complaints, digestive system symptoms, and bowel symptoms was high. Therefore, there is a need for measures and management for continuous health care and health promotion in accordance with students' symptoms and age at each grade level.

• Journal of dental hygiene science
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• v.16 no.6
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• pp.481-487
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• 2016

The elderly population with dementia is rapidly growing in South Korea. The aim of this study was to investigate the relationship between dementia and oral health in 197 subjects aged ${\geq}65$ years. The questionnaire included questions on subjective health status, subjective health concern, subjective oral health status and behavior, mastication ability, Oral Health Impact Profile-14 (OHIP-14), and Korean Dementia Screening Questionnaires (KDSQ). Oral examination was conducted by a single dentist to evaluate upper or lower denture use, and determine the numbers of remaining and functioning teeth, including implant and fixed prosthesis. The subjects who required a dementia test (KDSQ-C [cognition] of ${\geq}6$) had significant differences in systemic disease prevalence rate, subjective health status, subjective health concern, KDSQ-V (vascular disease) score, KDSQ-D (depression) score, subjective oral treatment need, key food mastication ability and OHIP-14 score compared to the healthy subjects. The proportion of denture wearers, total remaining teeth, total functioning teeth, toothbrushing frequency, oral pain severity, symptoms of periodontal disease, subjective oral health status, and subjective oral health concern showed no significant differences between the two groups. KDSQ-C and OHIP-14 scores showed a strong positive relationship, while KDSQ-C score and total remaining teeth or key food mastication ability showed a weak negative relationship. In the multiple regression analysis, the KDSQ-D, KDSQ-V, and OHIP-14 scores influenced the KDSQ-C scores. We suggest a relationship between oral health and cognitive impairment.

• Korean Journal of Heritage: History & Science
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• v.39
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• pp.95-130
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• 2006

Japanese government college researchers, including Sekino Tadashi(關野貞), have conducted research studies and collected data, on overall Korean cultural relics as well as Silla tumuli(新羅古墳) in the early modern times under the Japanese imperialistic rule. They were supported by the Meichi government in the early stage of research, by the Chosun government-general, and by their related organizations after Korea was coIonialized to carry out investigations on Korean antiquities, fine arts, architecture, anthropology, folklore, and so on. The objective for which they prosecuted inquiries into Korean cultural relics, including Silla tumuli, may be attributed to the purport to find out such data as needed for the theoretical foundation to justify their colonialization of Korea. Such a reason often showed locally biased or distorted views. Investigations and surveys had been incessantly carried out by those Japanese scholars who took a keen interest in Korean tumuli and excavated relics since 1886. 'Korea Architecture Survey Reports' conducted in 1904 by Sekino in Korea gives a brief introduction of the contents of Korean tumuli, including the Five Royal Mausoleums(五陵). And in 1906 Imanishi Ryu(今西龍) launched for the first time an excavation survey on Buksan Tumulus(北山古墳) in Sogeumgangsan(小金剛山) and on 'Namchong(南塚)' in Hwangnam-dong, which greatly contributed to the foundation of a basic understanding of Wooden chamber tombs with stone mound(積石木槨墳) and stone chambers with tunnel entrance(橫穴式石室墳). The ground plan and cross section of stone chambers made in 1909 at his excavation survey of seokchimchong(石枕塚) by Yazui Seiyichi(谷井第一) who majored in architecture made a drawing in excavation surveys for the first time in Korea, in which numerical expressions are sharply distinguished from the previous sketched ones. And even in the following excavation surveys this kind of drawing continued. Imanishi and Yazui elucidated that wooden chambers with stone mound chronologically differs from the stone chambers with tunnel entrance on the basis of the results of surveys of the locational characteristics of Silla tumuli, the forms and size of tomb entrance, excavated relics, and so forth. The government-general put in force 'the Historic Spots and Relics Preservation Rules' and 'the Historic Spots Survey Council Regulations' in 1916, establishing 'Historic Spots Survey Council and Museum Conference. When museums initiated their activities, they exhibited those relics excavated from tumuli and conducted surveys of relics with the permission of the Chosun government-general. A gold crown tomb(金冠塚) was excavated and surveyed in 1921 and a seobong tomb(瑞鳳塚) in 1927. Concomitantly with this large size wooden chamber tombs with stone mound attracted strong public attention. Furthermore, a variety of surveys of spots throughout the country were carried out but publication of tumuli had not yet been realized. Recently some researchers's endeavors led to publish unpublished reports. However, the reason why reports of such significant tumuli as seobong tomb had not yet been published may be ascribed to the critical point in those days. The Gyeongju Tumuli Distribution Chart made by Nomori Ken(野守健) on the basis of the land register in the late 1920s seems of much significance in that it specifies the size and locations of 155 tumuli and shows the overall shape of tumuli groups within the city, as used in today's distribution chart. In the 1930s Arimitsu Kyoichi(有光敎一) and Saito Tadashi(齋藤忠) identified through excavation surveys of many wooden chamber tombs with stone mound and stone chambers with tunnel entrance, that there were several forms of tombs in a tomb system. In particular, his excavation survey experience of those wooden chamber tombs with stone mound which were exposed in complicated and overlapped forms show features more developed than that of preceding excavation surveys and reports publication, and so on. The result of having reviewed the contents of many historic spots surveyed at that time. Therefore this reexamination is considered to be a significant project in arranging the history of archaeology in Korea.

• Journal of the Korean Geosynthetics Society
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• v.3 no.2
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• pp.13-21
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• 2004

This paper deal with the analysis of the causes about case of collapsed reinforced-soil retaining wall. The analysis of the cause was carried through experimentation, slop stability analysis and literature study. The experimentation treated the large direct shear test, the hydraulic conductivity test and the other basic test through backfill extraction from collapsed reinforced-soil retaining wall. The ultimate tensile strength was established by rib tensile strength test of geogrid. The analysis of internal and external stability of reinforced-soil retaining wall was performed on the basis of parameters. The result of analysis, reinforced-soil retaining wall and the slope at the dry season are stable. However, the factors that fine-grained soil at hydrometer test exceed the standard of the design, rainfall duration is too long at the time of collapse and monthly pricipitation is heavy, which are causes of the collapse.

• Proceedings of the Korean Society for Agricultural Machinery Conference
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• 2017.04a
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• pp.73-73
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• 2017

가축의 영양소 요구량 유지, 비육, 증체, 생산, 번식, 계절환경에 따라 달라지는 변동요인을 감안하여 하루 동안에 필요로 하는 영양소 요구량을 충족하도록 여러 종류의 사료를 혼합한 TMR(Total Mixed Ration)사료의 중요성이 커지고 있다. 이에 가축의 생산성 향상(등급 향상)과 축산농가의 영농비용 절감, 생력화를 위해 범용적으로 사용가능한 TMR플랜트의 개발이 반드시 필요하다. 본 연구에서는 사료비절감을 위한 식품부산물 발효탱크의 개발을 통해 발효탱크 밑 부분을 구성하고 있는 스위프오거와 이를 고정하면서 Z축으로 회전하는 고정부를 대상으로 하여 시각화 할 수 있는 FEM 시뮬레이션 기법을 이용하여 작업 중 적용되는 하중에 대해 충분한 구조 안전성을 가지고 있는지 해석하였다. 스위프오거의 재질은 SM45C, 작용하는 하중은 감속기의 출력량, RPM을 이용하여 토크 값을 구하고 조사료와 부산물사료가 포함된 TMR사료의 무게와 스위프오거의 단면적을 이용하여 압력 값을 도출하였다. 하지만 부산물사료가 발효되면서 저장탱크를 통해 배출되기 때문에 전체 사료 무게가 줄어 스위프오거에 작용하는 압력 또한 작아지는 것을 확인하였다. 이에 본 연구에서는 저장탱크에서 TMR사료가 배출되기 직전의 가장 높은 압력 상태를 가정하였다. 이 가정을 통해 토크 값은 $1.4N{\cdot}m$, 압력 값은 43 Mpa으로 나타났고 이를 바탕으로 구조해석을 진행하였다. 그 결과 스위프오거는 고정단 부근에서 최대 폰 미세스 응력 310 Mpa이 발생하여 구조적으로 가장 취약한 것으로 나타났다. 하지만 이는 SM45C의 항복강도인 343 Mpa 보다 낮아 안전한 것으로 분석된다. 또한 사료가 배출되면서 스위프오거에 작용하는 압력이 작아져 폰 미세스 응력도 작아지는 것으로 나타났다.

• Tunnel and Underground Space
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• v.22 no.3
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• pp.205-213
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• 2012

In this study, scaled model tests were performed to investigate the stability of twin tunnels constructed in anisotropic rocks with $30^{\circ}$ inclined bedding planes under the condition of lateral pressure ratio, 2. Five types of test models which had respectively different pillar widths and shapes of tunnel sections were experimented, where both crack initiating pressures and deformation behaviors around tunnels were investigated. The models with shallower pillar width showed shear failure of pillar according to the existing bedding planes and they were cracked under lower pressure than the models with thicker pillar width. In order to find the effect of tunnel sectional shape on stability, the models with four centered arch section, circular section and semi-circular arch section were experimented. As results of the comparison of the crack initiating pressures and the deformation behaviors around tunnels, the semi-circular arched tunnel model was the most unstable whereas the circular tunnel model was the most stable among them. Furthermore, the results of FLAC analysis were qualitatively coincident with the experimental results.

• Proceedings of the Korea Water Resources Association Conference
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• 2009.05a
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• pp.1351-1355
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• 2009

과거에 발생한 극한홍수기록을 역사기록에서 확인하고, 재해석하는 것은 근대적 관측기록에 100년 내외의 극한홍수 자료 기간을 획기적으로 확장할 수 있으며, 장기간의 정성적, 정량적 극한홍수기록으로부터 극한홍수의 발생 경향을 파악할 수 있고, 설계에도 반영하여 극한홍수에 안전한 기준을 작성할 수 있다. 본 연구에서는 극한홍수의 변화특성을 분석하기 위해 청계천 유역에 대한 극한홍수 사례분석을 수행하고자 하였다. 즉, 유역홍수유출모형 및 하천수리모형을 활용하여 청계천에서 발생한 과거 극한홍수를 평가하고 역사기록을 활용하여 공간적으로 해석하고자 하였다. 이를 위하여 과거 청계천 유역의 토지이용 현황을 역사문헌자료를 이용하여 구축하였다. 과거 청계천의 토지이용은 산림, 주거지역, 하천, 도로, 공원 및 녹지 등 총 5개로 분류하였다. 과거 청계천의 극한홍수량 산정은 HEC-HMS를 이용하였으며 사용된 강우자료는 과거 측우기 우량 중 최대강우량인 1885년 7월 16일의 392 mm와 200 mm를 넘는 최저강우량인 1828년 7월 4일의 202 mm를 이용하였다. 또한, HEC-RAS를 이용하여 최하류인 오간수문에서 최상류인 송기교까지의 본류구간에 대하여 과거 청계천 유역의 홍수량에 따른 홍수위를 계산하였다. 모형의 입력자료로는 하도구간 및 하천단면, 조도계수, 경사, 상 하류단 경계조건 등이 필요하다. 본 연구에서는 청계천 개수계획평면종단도(1936년, 경성부), 준천사실(1760년), 동국여지비고(1870년), 조선지형도집성(1921), 청계천 유물 발굴조사보고서(2006)의 상세 하도 구간 자료 및 종단도 자료를 이용하여 모의 분석하였다.

• Proceedings of the Korean Society of Dyers and Finishers Conference
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• 2011.03a
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• pp.105-105
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• 2011

국내 해양레저산업 중 세일요트산업은 현재 초기시장을 형성하고 있으나, 현재 정부의 해양레저 활성화 정책과 해양레저 인구 또한 관련 협회, 클럽 등의 중심으로 급속한 증가세를 이루고 있다. 이에 요트수요 증대에 따라 요트 관련 부품 소재의 경우에도 향후 그 수요가 대폭 증가할 것으로 예상되어지고 있으며, 그 중 요트용 돛(Sail)의 경우에는 전량 해외 수입에 의존하고 있어 제품개발을 통해 국산화함으로써 해외 제품의 수입대체가 요구되고 있다. 본 연구는 해외의 산업용 폴리에스터 원사로 제조된 요트세일 제품의 특성 및 성능 분석 결과와 국산 고강력 폴리에스터 소재로 제조된 요트 세일 개발 제품의 물성 및 성능을 비교 분석하고자 한다. 세일 제품 개발을 위해 해외 요트용 세일 제품을 분석한 결과, 소재는 고상중합형태의 폴리에스터 산업용 원사를 사용하여 직물자체의 고강도 및 저신도 특성발현을 위한 고밀도 제직을 실시한 것으로 분석 되었으며, 가공에서는 해양에서 사용하는 세일 직물의 특성 상 일광 및 자외선에 대한 내구성을 높이고, 황변을 방지할 수 있도록 하기 위해 직물표면에 멜라민계 수지를 이용한 함침방식의 특수코팅을 실시한 것으로 분석되었다. 이러한 해외 요트용 세일 제품의 분석결과를 바탕으로 국산 고강력 폴리에스터 고밀도 직물에 자외선 및 일광에 대한 내구성이 우수한 무황변 타입의 폴리에스터계 수지를 사용하여 단면 코팅으로 양면코팅 가공효과를 부여하는 나이프 방식의 특수코팅, 에이징 처리를 통해 세일을 제조하였다. 본 연구에서는 제조된 세일 직물 제품에 대해, 물리적 특성을 분석하기 위해 인장 강신도, 무게, 두께 및 주사전자현미경 관찰 등의 테스트를 실시하였으며, 세일 성능 분석을 위해 공기투과도, 일광견뢰도 자외선 조사 후 강도변화, 황변 Test 등의 테스트를 실시하여, 해외 선진 제품과 개발제품의 물성 및 성능에 대해 고찰하였다.

• Journal of the Korean Institute of Gas
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• v.15 no.5
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• pp.13-18
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• 2011

Experimental studies were carried out to investigate the characteristics of explosion mitigations by varying concentrations of agar gel barriers in an explosion chamber, 1400 mm in length, with a square cross-section of $100{\times}100mm^2$. Another extension chamber, $100{\times}100{\times}300mm^3$, was made to hold a gel barrier. Four different gel concentrations were used in the measurements: 2, 3, 4, 5 %(by weight of gel). Displacement of the gel barrier was measured using a high speed camera, and pressure development was measured using pressure transducers and a data acquisition system. It was found that as the concentrations of the gel barriers increased, the gel rupture time and the time taken to reach the maximum pressure increased. It was also found that the increment of gel concentrations increased the reduction percentage in the maximum pressure between before and after gel barrier.

• Journal of Korean Society of Steel Construction
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• v.20 no.3
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• pp.437-444
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• 2008

The use of imported structural steel tubes has been increased in domestic construction field because of its low price, but the mechanical properties of those steel tube are not verified exactly. This study includes coupon test and stub - column compression test on the structural steel tube. The compression test of stub - column was performed to characterize and quantify the material characteristic and strength of column compatibility, in which we compared the experiment formula and the abstract formula by the application of the LRFD standard formula and multiple column curve.