• Ocean and Polar Research
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• 제31권3호
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• pp.239-246
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• 2009

Long-term observations were conducted between 1997 and 2002 to examine the variability of the vertical temperature structure in the Youngsan Estuary, southwest Korea, in summer. The observed hydrographic data revealed that the temperature minimum layer in the middle depth persisted through the entire summer of 2000 but was rarely observed in other years. The variability in the vertical structure might be affected by the air temperature during the previous winter and the density difference between the open sea and the estuary. In 2000, the air temperature in the previous winter was lowest and the horizontal density difference during summer was largest. The large horizontal density difference probably produced more active driving of warm water along the bottom, which would have intruded into the Youngsan Estuary. Furthermore, the cold previous winter would have provided a better condition for maintaining cold temperatures in the middle water layer for a longer period.

• 한국초전도ㆍ저온공학회논문지
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• 제4권1호
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• pp.78-83
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• 2002

Since the KSTAR superconducting magnet structure should be maintained at a cryogenic temperature of about 4 K, even a small amount of heat might be a major cause of the temperature rise of the structure. The Joule heating by eddy currents induced in the magnet structure during the KSTAR operation was found to be a critical parameter for designing the cooling scheme of the magnet structure as well as defining the requirements of the refrigerator for the cryogenic system. Based on the Joule heating calculation, it was revealed that the bulk temperature rise of the magnet coil structure was less than 1 K. The local maximum temperature especially at the inboard leg of the TF coil structure increased as high as about 21 K for the plasma vertical disruption scenario. For the CS coil structure, the maximum temperature was obtained from the PF fast discharging scenario. This means that the vertical disruption and PF fast discharging scenarios are the major scenarios for the design of TF and CS coil structures, respectively. For the reference scenario, the location of maximum temperature spot changes according to the transient current variation of each PF coil.

• Journal of the korean society of oceanography
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• 제31권2호
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• pp.64-74
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• 1996

Numerical experiments of OAT (Ocean Acoustic Tomography) are carried out in the East Sea of Korea where the canonical ocean has been perturbed by a mesoscale warm eddy and a thermal front. In order to estimate the horizontal and vertical structure of water temperature of the perturbed ocean, the experimental area is divided into 16 cells with 8 pairs of sources and receivers for a horizontal slice and the water column is divided into 8 layers for a vertical slice. The inversely estimated temperature field by using SVD (Singular Value Decomposition) method reveals the eddy and frontal structure clearly. The rms errors of the two horizontal slices are less than $0.4^{\circ}C$ and $1.7^{\circ}C$ at 400 m and 200 m depths, respectively, while the error in the vertical slice is less than $1.0^{\circ}C.$ For better estimation of temperature by OAT method, particularly for the East Sea, a range-dependent ray model should be used to solve the forward problem. At the same time, improvement in computing the refracted ray path between vertical layers is required to obtain more accurate travel time information. The results of the present experiment give rise to a possibility of application of OAT in remote sensing of the ocean thermal structure.

• 한국가구학회지
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• 제25권2호
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• pp.122-128
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• 2014

Recently, many studies have conducted to satisfy a physical need of human between environment of light on space, so an atrium structure has been applied to cultural complex. However, this structure brings about many problems such as overheating in summer, excessive vertical temperature differences, condensation, diffusion of noise, effect of echo, and withering landscapes. Especially, in this research, thermal comfort by difference of vertical temperature in the space of atrium and the optical characteristics of glass skins of the atrium could be remarkably effected by solar flux entering indoors.

• 한국주거학회논문집
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• 제1권1호
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• pp.91-102
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• 1990

The aim of this study is to discover thermal characteristics of Ondol heating systems. The housing subjected was categorized into detached single family houses and apartments, reinforced concrete and brick structures, intermittent and continous heating system, and the space subjected was bedroom. In order to understand the thermal characteristics of each floor heating systems, the vertical distribution of indoor temperature and the distribution of surface temperature on the floor were measured. The vertical distribution of indoor temperature except the measurement point 1 largely showed average temperature distribution, and the temperature of the measurement point 1 in the housing surveyed showed the highest temperature in the house "sample A" because of the radiation heating from the floor of the Ondol room. As the result of the measurement, the thermal characteristics of each heating system were more stable distribution in apartments of R.C structure.structure.

• 동력기계공학회지
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• 제20권5호
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• pp.72-77
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• 2016

The present study investigates noise and condensation characteristics of polyvinyl chloride (PVC), which is widely used for drainage piping materials, complex double structure by comparing to those of PVC single structure piping materials. In addition, effects of insulation on drainage noise has been measured experimentally. As the results of the experiments, noise reduction effect of PVC complex double structure is superior to that of PVC single structure in terms of elbow and vertical piping materials which are employed for drainage pipes of toilet bowls and bathtub. The insulation barely have effect on the noise reduction in case of the PVC single structure since there is almost no changes in noise occurrence even though the insulation is applied on both elbow and vertical piping materials. Temperature differences between inside and outside of the pipes have been measures for the PVC single and complex double structures as well. In consequence, outside temperature of the PVC complex double structure is higher than that of the PVC single structure. The condensation occurrence time of the PVC complex double structure shows a distinct difference from that of the PVC single structure, thus, the PVC complex double structure has outstanding effect on preventing the condensation.

• 한국환경과학회지
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• 제11권3호
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• pp.155-160
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• 2002

Using measured data at Daegu by tethersonde for the period of 1984∼1987, we have investigated the lower atmospheric boundary layer structure including relationships between inversion layer and meteorological factors(wind and temperature), and the inversion strength and inversion height. The inversion layer was defined from the vertical temperature profile and its strength was analyzed with the wind shear as well as the vertical temperature gradient. From October to January, measured inversion layer isn't destroyed, however, in June, after sun rise, it is destroyed by surface heating and mixed layer is developed from surface. According to Pasquill stability classes, the moderately stable cases dominated. It's the larger vertical temperature gradient the lower SBL height. We have introduced B(bulk turbulence scale) which indicated SBL height. It's larger B, the higher SBL height and vice versa. It was noted that the bulk turbulence scale (B) is appropriate to determine the stable boundary layer height.

• 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.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2002년도 춘계학술대회 논문집
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• pp.207-212
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• 2002

The actual buckling of the railroad track structure is suspected to be a complex interaction between the vertical, lateral and torsional modes. To make the analysis tractable, however, most studies restrict themselves to either the vertical or the horizontal plane. Based on a comprehensive and realistic three-dimensional track model developed in the previous study, three dimensional buckling analysis of CWR track subjected to temperature load was performed. Using the study on buckling temperature and mode, sensitivity of track components such as tie spacing, ballast resistance, stiffness of pad-fastening system and rail size were investigated.

• 한국초전도저온공학회:학술대회논문집
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• 한국초전도저온공학회 2002년도 학술대회 논문집
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• pp.56-59
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• 2002

Since the KSTAR magnet structure should be maintained at cryogenic temperature of about 4.5 K, even a small amount of heat might be a major cause of the temperature rising of the superconducting magnet structure. The Joule heating by eddy current induced on the magnet structure during the KSTAR operation was found to be a critical parameter for designing the cooling scheme of the magnet structure as well as defining the requirements of the refrigerator for the cryogenic system. Based on the Joule heating calculation, it was revealed that the bulk temperature rising of the magnet coil structure was less than 1 K. The local maximum temperature especially at the inboard leg of the TF coil structure increase as high as about 21 K for the plasma vertical disruption scenario. For the CS coil structure maximum temperature of 8.4 K was obtained from PF fast discharging scenario.