• Structural Engineering and Mechanics
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• 제53권5호
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• pp.881-896
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• 2015

In this study, a method for fatigue performance estimation of deepwater steel catenary riser (SCR) under short-term vortex-induced vibration was investigated for selected S-N curves. General tendency between S-N curve capacity and fatigue performance was analysed. SCRs are generally used to transport produced oil and gas or to export separated oil and gas, and are exposed to various environmental loads in terms of current, wave, wind and others. Current is closely related with VIV and it affects fatigue life of riser structures significantly. In this regards, the process of appropriate S-N curve selection was performed in the initial design stage based on the scale of fabrication-related initial imperfections such as welding, hot spot, crack, stress concentration factor, and others. To draw the general tendency, the effects of stress concentration factor (SCF), S-N curve type, current profile, and three different sizes of SCRs were considered, and the relationship between S-N curve capacity and short-term VIV fatigue performance of SCR was derived. In case of S-N curve selection, DNV (2012) guideline was adopted and four different current profiles of the Gulf of Mexico (normal condition and Hurricane condition) and Brazil (Amazon basin and Campos basin) were considered. The obtained results will be useful to select the S-N curve for deepwater SCRs and also to understand the relationship between S-N curve capacity and short-term VIV fatigue performance of deepwater SCRs.

• 한국콘텐츠학회논문지
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• 제7권10호
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• pp.157-164
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• 2007

인류가 살아남기 위해서 수렵과 채취를 하는 동안 저장을 위해 자연스럽게 만들어진 그룻은 위대한 발명 이었다. 집을 지을 때도 자연의 일부로서 자연과 닮은 집을 지었고, 사계절을 지내기 위해 음식을 저장하는 방법을 연구하여 집안 곳곳에 저장창고와 저장용기를 배치하여 계절에 관계없이 음식을 먹을 수 있도록 했다. 그러나 현대에 와서 사회의 변화와 과학의 발달로 자연의 순수한 재료로 만들어지던 그룻과 저장용 기들이 플라스틱과 철이라는 새로운 재료들로 만들어져 생활의 편리함을 안겨주었으나 그에 따른 부작용도 생겨나고 있고 집집마다 냉장고에 김치를 보관하나 예전의 그 맛이 아니다. 요즈음 웰빙 열풍과 함께 한국의 음식이 세계화 되고 있고, 김치의 세계화로 김치를 저장했던 옹기에 대한 관심도 증가하고 있다. 본 연구는 예부터 발전해온 도기의 일종인 옹기의 발전사를 문헌을 통해 알아보고 과학적인 실험을 통해 선조들의 지혜가 담긴 옹기의 특성을 연구함으로서 옹기의 장점과 필요성을 알리고 더 나아가 옹기의 특성을 활용한 친환경적인 기물의 개발에 힘쓰도록 유도함에 그 목적이 있다.

• 대한원격탐사학회:학술대회논문집
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• 대한원격탐사학회 2006년도 Proceedings of ISRS 2006 PORSEC Volume I
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• pp.150-152
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• 2006

The DISCOVER Project (${\underline{D}}istributed$ ${\underline{I}}nformation$ ${\underline{S}}ervices$ for ${\underline{C}}limate$ and ${\underline{O}}cean$ products and ${\underline{V}}isualizations$ for ${\underline{E}}arth$ ${\underline{R}}esearch$) is a NASA funded Earth Science REASoN project that strives to provide highly accurate, carefully calibrated, long-term climate data records and near-real-time ocean products suitable for the most demanding Earth research applications via easy-to-use display and data access tools. A key element of DISCOVER is the merging of data from the multiple sensors on multiple platforms into geophysical data sets consistent in both time and space. The project is a follow-on to the SSM/I Pathfinder and Passive Microwave ESIP projects which pioneered the simultaneous retrieval of sea surface temperature, surface wind speed, columnar water vapor, cloud liquid water content, and rain rate from SSM/I and TMI observations. The ocean products available through DISCOVER are derived from multi-sensor observations combined into daily products and a consistent multi-decadal climate time series. The DISCOVER team has a strong track record in identifying and removing unexpected sources of systematic error in radiometric measurements, including misspecification of SSM/I pointing geometry, the slightly emissive TMI antenna, and problems with the hot calibration source on AMSR-E. This in-depth experience with inter-calibration is absolutely essential for achieving our objective of merging multi-sensor observations into consistent data sets. Extreme care in satellite inter-calibration and commonality of geophysical algorithms is applied to all sensors. This presentation will introduce the DISCOVER products currently available from the web site, http://www.discover-earth.org and provide examples of the scientific application of both the diurnally corrected optimally interpolated global sea surface temperature product and the 4x-daily global microwave water vapor product.

• 혜화의학회지
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• 제8권2호
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• pp.259-272
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• 2000

About the acupuncture & moxibustion therapy of allergic rhnitis, nasal discharge(鼻涕), stuffy nose(鼻塞), and rhinorrlea with turbid discharge(鼻淵), the results are obtained as follows: 1. It appeared that the reasons for allergic rhnitis are the lung's contacting to Wind-Coid(風寒), Damhwa(痰火), and accumulated fever of stomach, the reasons for nasal discharge(鼻涕) is the Cold-Hot of a lung. the reasons for stuffy nose(鼻塞) is the harmonization of the Lung(肺氣), the reasons for the rhinorrlea with turbid discharge(鼻淵) are the heat of the Brain(腦熱), heat of the Gallbladder(膽熱), most probably. 2. When we do a acupuncture & moxibustion therapy for the allergic rhnitis, we used P'ungmun(風門), Shinjong(神庭), mostly. For the nasal diacharge(鼻涕) ; Yonghyang(迎香), P'ungmun(風門), Sangsong(上星) and Sugu(水溝) were the most useful acupuncture point. For the stuffy nose(鼻塞) ; Sangsong(上星), Yonghyang(迎香), Hapkok(合谷), and Sugu(水溝) were used most frequently. For the rhinorrlea with turbid discharge(鼻淵); Sangsong(上星), Hapkok(合谷), Yonghyang(迎香), and P'ungji(風池) were the best acupuncture point. 3. Concerning the frequencies of the acupuncture & moxibustion therapy for these four symptoms, Bladder Meridian(膀胱經) and Governor Vessel Meridian(督脈) were the most useful ones. As to the acupuncture point, Sangsong(上星), Yonghyang(迎香), Sugu(水溝) and Hapkok(合谷) were used most repeatedly.

• 한국환경과학회지
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• 제21권12호
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• pp.1511-1521
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• 2012

An attempt is made to analyse characteristic features of heavy rainfalls which occur at the metropolitan area of the Korean peninsular the on- and off- Changma season. For this, two representative heavy rainfall episodes are selected; one is the on-Changma season wherein a torrential rain episode happened at Goyang city on 12 July 2006, and the other is the off-Changma season, a heavy rainfall event in Seoul on 21 September 2006. Both recorded considerable amounts of precipitation, over 250mm in a half-day, which greatly exceeded the amount expected by numerical prediction models at those times, and caused great damage to property and life in the affected area. Similarities in the characteristics of both episodes were shown by; the location of upper-level jet streak and divergence fields of the upper wind over heavy rainfall areas, significantly high equivalent potential temperatures in the low atmospheric layer due to the entrainment of hot and humid air by the low-level jet, and the existence of very dry air and cold air pool in the middle layer of the atmosphere at the peak time of the rainfall events. Among them, differences in dynamic features of the low-level jet and the position of rainfall area along the low-level jet are remarkable.

• 유체기계공업학회:학술대회논문집
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• 유체기계공업학회 2006년 제4회 한국유체공학학술대회 논문집
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• pp.187-190
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• 2006

In the present study, effects of tree-stream turbulence and surface trip wire on the flow past a sphere at $Re\;=\;0.4\;{\times}\;10^5\;{\sim}\;2.8\;{\times}\;10^5$ are investigated through wind tunnel experiments. Various types of grids are installed upstream of the sphere in order to change the tree-stream turbulence intensity. In the case of surface trip wire, 0.5mm and 2mm trip wires are attached from $20^{\circ}\;{\sim}\;90^{\circ}$ at $10^{\circ}$ interval along the streamwise direction. To investigate the flow around a sphere, drag measurement using a load cell, surface-pressure measurement, surface visualization using oil-flow pattern and near-wall velocity measurement using an I-type hot-wire probe are conducted. In the variation of free-stream turbulence, the critical Reynolds number decreases and drag crisis occurs earlier with increasing turbulence intensity. With increasing Reynolds number, the laminar separation point moves downstream, but the reattachment point after laminar separation and the main separation point are fixed, resulting in constant drag coefficient at each free-stream turbulence intensity. At the supercritical regime, as Reynolds number is further increased, the separation bubble is regressed but the reattachment and the main separation points are fixed. In the case of surface trip wire directly disturbing the boundary layer flow, the critical Reynolds number decreases further with trip wire located more downstream. However, the drag coefficient after drag crisis remains constant irrespective of the trip location.

• Asian-Australasian Journal of Animal Sciences
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• 제28권3호
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• pp.442-450
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• 2015

Climate temperature affects animal production. This study was conducted to evaluate whether climatic conditions affect beef carcass characteristics of Korean cattle steers. The monthly carcass characteristics of Korean cattle steers (n = 2,182,415) for 8 yr (2006 through 2013) were collected from the Korean Institute for Animal Products Quality Evaluation. Daily climate temperature (CT) and relative humidity (RH) data were collected from the Korean Meteorological Administration. Weather conditions in South Korea during summer were hot and humid, with a maximum temperature of $28.4^{\circ}C$ and a maximum RH of 91.4%. The temperature-humidity index (THI), calculated based on CT and RH, ranges from 73 to 80 during summer. Winter in South Korea was cold, with a minimum temperature of $-4.0^{\circ}C$ and a wind-chill temperature of $-6.2^{\circ}C$. Both marbling score (MS) and quality grade (QG) of Korean cattle steer carcasses were generally best (p<0.05) in autumn and worst in spring. A correlation analysis showed that MS and QG frequencies were not associated (p>0.05) with CT. Yield grade (YG) of Korean cattle steer carcasses was lowest (p<0.05) in winter (November to January) and highest in spring and summer (May to September). A correlation analysis revealed that YG frequency was strongly correlated ($r{\geq}0.71$; p<0.01) with CT and THI values. The rib eye area, a positive YG parameter, was not associated with CT. Backfat thickness (BT), a negative YG factor, was highest in winter (November and December). The BT was strongly negatively correlated ($r{\leq}-0.74$; p<0.01) with CTs. Therefore, the poor YG during winter is likely due in part to the high BT. In conclusion, YG in Korean cattle steer carcasses was worst in winter. QGs were not associated with winter or summer climatic conditions.

• Nuclear Engineering and Technology
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• 제52권2호
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• pp.248-257
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• 2020

This study presents an initial design for a novel system consisting in a coupled nuclear reactor and a phase change material-based thermal energy storage (TES) component, which acts as a buffer and regulator of heat transfer between the primary and secondary loops. The goal of this concept is to enhance the capacity factor of nuclear power plants (NPPs) in the case of high integration of renewable energy sources into the electric grid. Hence, this system could support in elevating the economics of NPPs in current competitive markets, especially with subsidized solar and wind energy sources, and relatively low oil and gas prices. Furthermore, utilizing a prismatic-core advanced high temperature reactor (PAHTR) cooled by a molten salt with a high melting point, have the potential in increasing the system efficiency due to its high operating temperature, and providing the baseline requirements for coupling other process heat applications. The present research studies the neutronics and thermal hydraulics (TH) of the PAHTR as well as TH calculations for the TES which consists of 300 blocks with a total heat storage capacity of 150 MWd. SERPENT Monte Carlo and MCNP5 codes carried out the neutronics analysis of the PAHTR which is sized to have a 5-year refueling cycle and rated power of 300 MW_th. The PAHTR has 10 metric tons of heavy metal with 19.75 wt% enriched UO₂ TRISO fuel, a hot clean excess reactivity and shutdown margin of $33.70 and -$115.68; respectively, negative temperature feedback coefficients, and an axial flux peaking factor of 1.68. Star-CCM + code predicted the correct convective heat transfer coefficient variations for both the reactor and the storage. TH analysis results show that the flow in the primary loop (in the reactor and TES) remains in the developing mixed convection regime while it reaches a fully developed flow in the secondary loop.

• 동의신경정신과학회지
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• 제11권2호
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• pp.189-200
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• 2000

Object : The purpose of this study is assistant to medical treatment for patient, who suffers from headache, by classifing etiologies of headache and investigating using meridian and acupuncture point.Method : By considering through the oriental literature, we investigated etiologies and frequency of using meridian and acupuncture point on headache.Result:1. The Oriental etiologies of headache is classified in 'wind(風)', 'hot and feverish(熱)', 'humidity(濕)', 'cold(寒)', 'defidiency of qi(氣處)', 'deficiency of blood(血虛)', 'extravasated blood(瘀血)', 'asthenia of kidney(賢處)', 'anger by depression(鬱怒)', 'Damhwa(痰火)'2. The frequently used meridians on headache are followings : the 1st is Choksoyang-Tam-Kyong(足少陽膽經), the 2nd Choktaeyang-Pabggwabg-Kyong(足太陽膀胱經), the 3rd Tok-maek(督脈), and the 4th Chokyangmyong Wi-Kyong(足陽明胃經).3. The frequently used acupuncture points on headache are followings : the 1st is paek'oe(百會), the 2nd Hapkok(合谷) and the 3rd P'ungji(風池).Conclusion:1. The books about treatment of headache by using acupuncture are The Yellow Emperor's Classic on internal Medicine(黃帝內經) and Gab-UI-Kyoung(甲乙經) and so on.2. In The Yellow Emperor's Classic on Internal Medicine(黃帝內經), they mainly used treatment by following the stream of meridian on headache.3. After Gab-U1-Kyoung(甲乙經), they suggested specialized acupunctre point.4. Three Yang meridians(三陽經) that has many acupuncture point located on head area, are related to medical treatment on headache.

• 수산해양기술연구
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• 제14권2호
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• pp.113-116
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• 1978

우리나라 근해의 열 에너지 이용 가능성을 알기 위하여 황해 동부해역의 연직온도차 분포상황 및 그 계절적 변동을 조사하였고, 이들과 해수유동과의 관련성에 관하여 고찰하였다. 하계에는 거안 약 40mile 해역인 125${\circ}$30'E 이서의 34${\circ}$N이북에 연직온도차가 16$^{\circ}C$ 이상 되는 곳이 존재하는 바, 이것은 따뜻한 황해 난류계수의 표면가열과 저층의 황해냉수에 기인하는 것으로 생각된다. 연안으로 갈수록 연직 온도차는 줄어지고, 거안 약 30mile 해역에서는 약 1$0^{\circ}C$이다. 이를 이용하여 온도차발전이 가능하다고 보아진다. 제주도 남부 및 서부해역은 연직 온도차가 약 14$^{\circ}C$ 이상을 보인다. 겨울에는 왕성한 대류혼합으로 연직 온도차는 거의 없어진다. 그러나 겨울에는 강한 계절풍이 계속 발전체계를 여름에는 온도차발전, 겨울에는 파력 및 풍력발전을 하는 방식으로 체계화하면 주년 계속 발전이 가능할 것이라 생각된다.