• 대한기계학회논문집B
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• 제20권5호
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• pp.1700-1716
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• 1996

The two-dimensional, unsteady, laminar conservation equations for mass, momentum, energy and species transport in the gas phase and mass, momentum and energy in the liquid phase are solved simultaneously in spherical coordinates in order to study heating and vaporization of a droplet entrained in the oscillating flow. The numerical solution gives the velocity and temperature distribution in both gas and liquid phase as a function of time. When the gas flow oscillates around an vaporizing droplet, the liquid flow circulates in the clockwise or counterclockwise direction and the temperature distribution in the liquid phase changes its shapes, depending on the gas fow direction. When the gas flow changes its direction of circulating liquid flow is opposite to the gas flow, forming two vortex circulating in the opposite direction. During the heating period, the difference in the maximum and minimum temperature is large, followed by the almost uniform temperature slightly below the boiling temperature. The mass and heat transfer from the droplet depend on the droplet temperature, droplet diameter and the magnitude of relative velocity, giving the droplet lifetime different from the d$^{2}$-law.

• 한국전기전자재료학회논문지
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• 제35권4호
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• pp.372-376
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• 2022

Since the ZnO varistor is a semiconductor device, the internal thermal distribution during the varistor operation is recognized as an important factor in the performance and deterioration of the varistor. For an optimal varistor structure design, the thermal runaway phenomenon during the varistor operation was interpreted using the Comsol 5.2 analysis program by a finite element analysis. The maximum temperature of the center measured in the cross section of the ZnO varistor was confirmed to increase as the temperature moved from the lower electrode to the center towards the upper electrode up to 572.6 K. The electrodes are thinned so that the influence of the Schottky barrier is not great. The heat gradient balance is determined to be improved when the electrode of the hybrid form is introduced. The thickness, density, pore distribution, impurity uniformity, and particle size of the ZnO varistor are required, and it is determined that the pyrolysis gradient will be improved regardless of the electrode thickness. When these results are applied to design the ZnO varistor, the optimal structure of the ZnO varistor can be obtained.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 1999년도 봄 학술발표회 논문집(I)
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• pp.299-304
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• 1999

Cracking of concrete is one of the main issues of structural design next to ensuring the load-bearing capacity. Thermal cracking is a recurring concern in the production of concrete structures in particular when large, massive structures are considered. Thremal stresses arise from the differential temperature distribution either within s sturcture or between newly cast sectons and adjoining older parts. There are many different methods of reducing thermal stresses. A method often used for reducing temperature within a structure, is to cool the inner core with embedded cooling pipes. In this study, finite element method is employed for thermal analysis of concrete structures. To calculate water temperature variation in pipe, the conservation of thermal energy in internal flow was adopted. The cooling effect of pipe cooling is studied with several factors like convective coefficient, water temperature, concrete heat characteristics

• 대한전기학회:학술대회논문집
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• 대한전기학회 2008년도 제39회 하계학술대회
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• pp.842-843
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• 2008

Many works on the temperature prediction of power apparatus have usually done by coupled magneto-thermal analysis. However, this method can not consider the internal gas or oil flow in the power apparatus. This paper proposes a new coupled magneto-thermal-flow analysis considering Navier-Stokes equations. The convection heat transfer coefficient is calculated analytically and is applied to the boundary condition to the proposed method. Temperature distribution of 145kV 40kA three-phase GIS bus bar model is obtained by coupled magneto-thermal-flow analysis and shows good agreement with the experimental data.

• Structural Engineering and Mechanics
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• 제76권5호
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• pp.579-590
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• 2020

This paper's objective is to investigate the effect of gravity on a micropolar thermoelastic medium with voids. The problem is assessed according to the three-phase-lag model. An analysis of the resulting non-dimensional displacement, temperature variation, and internal stress of the study material is carried out and presented graphically. The non-dimensional displacement, temperature, micro-rotation, the change in the volume fraction field and stress of the material are obtained and illustrated graphically. Comparisons are made with the results predicted by different theories for different values of gravity, the phase-lag of the heat flux and the phase-lag of the temperature gradient. The numerical results reveal that gravity and relaxation times have a significant influence on the distribution of the field quantities. Some notable insights of interest are deduced from the investigation.

• 한방안이비인후피부과학회지
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• 제10권1호
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• pp.209-246
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• 1997

In the literatual study on the Ecthyma, the results were as follows. 1. The pathogenic factors of Ecthyma is divided three parts. One is exogenous pathogenic factors which including the wind evil, wind heat and toxic material produced by wetness evil. Another is endogenous pathogenic factors which including the declination of kidney-yang, impairment of the liver and kidney, the lower classes of yin-fire, accumulation of wetness-heat in the spleen asthenia, impairment of the liver and kidney, wetness-heat of three yang, asthenic heat-syndrome of three yin. The other is pathogenic factors neither endogenous nor exogenous which including the food and living, uncontrol sexual excess, anxiety and angry, injury of skin, injury of insects and animals. 2. Five viscera which was concerned with Ecthyma are liver, spleen and kidney. 3. Frequent region of Ecthyma are S-36(足三里) and C-7(陰交). External Ecthyma was rose to wetness-heat of three yang channel that cured easily. Internal Ecthyma was rose to asthenic heat-syndrome of three yin channel that cured hardly. 4. In the frequency of prescription, the most numerous prescription is Bojungikgitang(補中益氣湯) and the next are Kyukgigo(隔紙膏) and Yukmijihwanghwan(六味地滉丸). 5. In the frequency of medicine, the most medicine is Calomelas(輕粉) which included Hydrargyrum(水銀) and the next are Olibanum(乳香) and Resina Commiphorae Myrrhae(沒藥) which regulating vital energy and pain control medicine used that in order to destroy insects and remove polson. 6. In classification of the medical action, medicine of clearing away summer-heat and heat evil and activating blood circulation to dissipate blood stasis used to be very busy which in order to remove the disorder of vital energy for virulent heat-evil. 7. In classification of four characters, the most part is warm medicine, the next are cold and cool medicine and there is a few that is hot medicine. 8. In classification of five tastes, the most numerous tastes are bitter and acrid, the next are sweet, salty and sour tastes. 9. In classification of virulence of medicine, the most part is non-toxic, the next are weakly and deadly poison. 10. In classification of channel distribution, the most is the medicine that belongs to liver channel, the next are the lung, spleen, stomach and kidney channel.

• 자원환경지질
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• 제38권6호
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• pp.717-729
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• 2005

일반적으로 대규모 건물의 피크 냉방 부하는 난방부하보다 크다. 북위도의 한냉한 지역에 소재한 대규모건물의 냉난방 설비는 건물 내부에서 생성되는 발열량과 태양으로부터 획득되는 열량에 따라 좌우된다. 최대 냉방부하에 적합하도록 냉난방설비와 지중루프를 설치하는데 소요되는 비용은 일반적으로 초기투자비가 적게 드는 전통적인 HVAC시스템에 비해 다소 고가이다. 빙축열조(Thermal ice storage, TES)시스템은 과거 수년동안 일반 HVAC에서 냉동기의 용량을 축소시키거나 최대 전력부하 시간대를 바꾸기 위해 사용되어온 기술이다. 일반적으로 건물 난방을 위해서는 보일러와 같은 전통적인 난방설비를 이용하고 그 다음날의 건물냉방을 위해서는 전력료가 저렴한 야간에 빙축을 시키는 빙축열기법을 이용한다. 얼음에서 추출한 잠열 에너지의 장점을 이용하기 위해 설계된 분배시스템(distribution system)과 열원과 열배출원(열침, sink)대신에 지중열 교환기(지중루프)를 이용하면 많은 장점이 있다. 공간 난방과 급탕을 공급하기위한 분리형 설비를 별도로 사용하지 않아도 된다. 공간난방용으로 소요되는 설비용량을 축소시킬 수 있으며-소요 지중열 교환기의 규격과 비용을 절감시킴은 물론 지열 HVAC시스템의 효율을 배가 시킬 수 있으며 온실가스 배출량을 대폭 감축시킬 수 있다. 또한 TES를 적용하면 대규모 건물의 냉난방부하와 열펌프의 용량을 $40\~60\%$ 정도 감축시킬 수 있으며 설비대수와 기계실 공간을 줄일 수 있다. 뿐만아니라 피크 냉난방부하를 토대로 설계한 지원 열펌프 시스템(Ground source heat pump system)의 지중루프를 $1/4\~1/3$가지 줄일 수 있어 도심지역에서 지중루프를 설치할 때 장애요인인 지중루프 설치공간문제와 지중암석의 열적특성문제를 동시에 해결할 수 있다.문이며, 따라서 $^{137}Cs$의 분포는 광물분포 보다는 TOC의 함량에 더 큰 영향을 받고 있음을 보여준다.과 위기 고조 단계, 그리고 갈등 해소 단계등 모든 시기에서 두 신문의 주요 행위자 구성에 있어서 차이가 나타났다. 다시 말해, 조선일보는 기본적으로 총파업을 둘러싼 문제의 구성과 발전, 해소 과정에서 정당이나 대통령, 야당 지도자 등과 같은 정치관련 행위자를 강조하고 있었다. 반면에, 한겨레는 대체로 로든 사건진행 단계에서 노동 관련 단체들과 시민단체의 역동적인 연대와 활동에 초점을 맞추고 있는 것으로 나타났다.술 후 24시간에 599.4$\pm$145.6, 678.8 $\pm$256.4였다(t-test, p < 0.05). 동종 수혈은 RAP군에서 34명 중 7명에서(20.6$\%$), 대조군에서는 46명중 16명에서(34.8$\%$) 시행되어, RAP군에서 유의하게 빈도가 낮았다(Chi-square test, p < 0.05). 결론: 역행성 자가 충전법은 심폐바이패스의 충전에 의한 혈액희석을 최소화함으로서, 개심술 후 출혈과 동종수혈을 또한 줄이는 데 효과적인 방법이 될 수 있다고 생각된다.타내지 않았다.성 교사, 가정 전공 교사가 그렇지 않은 교사보다 해석적, 해방적 행동목표를 더 중요하게 인식하고 있었다. 특히 가정교육 철학을 배운 경험이 있는 교사가 그렇지 않은 교사보다 해방적 행동체계 목표를 중요시하는 것으로 나타났다. 이 연구 결과는, 실천 비판적인 가정 교과의 본질을 구현하기 위해서는 주생활 영역의 교육과정에 기술적, 해석적, 해방적 행동에 대한 목표들을 고루 포함하여야 하며 특히 교사들이 중요하게 인식하는 해방적 행동에 대한 목표를 강조하여 적용할 필요가 있음을 시사하고 있다.교하여 유의한 차이가 관찰되지 않았다. 또한

• Computers and Concrete
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• 제18권5호
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• pp.1041-1051
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• 2016

In this study, the construction of a reinforced concrete bridge pier was analyzed from durability point of view. The goal of the study is to analyze the crack iniation condition due to construction and present some recommendations for construction conditions of the reinforced concrete bridge pier. The bridge is located at the western port area of Shenzhen, where the climate is high temperature and humidity. To control the cracking of concrete, a construction simulation was carried out for a heat transfer problem as well as a thermal stress problem. A shrinkage model for heat produced due to cement hydration and a Burger constitutive model to simulate the creep effect are used. The modelling based on Femmasse(C) is verified by comparing with the testing results of a real underground abutment. For the bridge pier, the temperature and stress distribution, as well as their evolution with time are shown. To simulate the construction condition, four initial concrete temperatures ($5^{\circ}C$, $10^{\circ}C$, $15^{\circ}C$, $20^{\circ}C$) and three demoulding time tips (48h, 72h, 96h) are investigated. From the results, it is concluded that a high initial concrete temperature could result in a high extreme internal temperature, which causes the early peak temperature and the larger principle stresses. The demoulding time seems to be less important for the chosen study cases. Currently used 72 hours in the construction practice may be a reasonable choice.

• 동의생리병리학회지
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• 제22권6호
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• pp.1378-1382
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• 2008

This study is aim to evaluate pulse diagnosis as indicators for classification of the pattern identifications in stroke patients. To get the clinical information, we recruited the onset 1 month stroke patients through the multicenter network which consists of 13 oriental hospitals. The clinical informations about three pairs of pulse wave form and levels of their significancy based on the case report form (CRF) were collected and their distribution in each pattern identification were analyzed. The results are as follows Fire-Heat group shows high portions of floating pulse, rapid pulse and solid pulse. Qi Defficiency group has a greater portion of deep pulse, slow pulse, deficient pulse. The well-defined character of Phlegm-Retained Fluid, Yin Defficiency, Static Blood groups cannot be explained by pulse wave form. These results show a rough relationship between the pulse diagnosis and pattern identifications of stroke therefore, further studies are required to determine the pulse diagnosis as significant indicators of stroke pattern identification.

• 대한한방내과학회지
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• 제45권1호
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• pp.1-10
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• 2024

Objectives: This study investigated the pattern identification (PI) and clinical index of Parkinson's disease (PD) for personalized diagnosis and treatment. Methods: This prospective observational multi-center study recruited 100 patients diagnosed with PD from two Korean medicine hospitals. To cluster new subtypes of PD, items on a PI questionnaire (heat and cold, deficiency and excess, visceral PI) were evaluated along with pulse and tongue analysis. Gait analysis was performed and blood and feces molecular signature changes were assessed to explore biomarkers for new subtypes. In addition, unified PD rating scale II and III scores and the European quality of life 5-dimension questionnaire were assessed. Results: The clinical index obtained in this study analyzed the frequency statistics and hierarchical clustering analysis to classify new subtypes based on PI. Moreover, the biomarkers and current status of herbal medicine treatment were analyzed using the new subtypes. The results provide comprehensive data to investigate new subtypes and subtype-based biomarkers for the personalized diagnosis and treatment of PD patients. Ethical approval was obtained from the medical ethics committees of the two Korean medicine hospitals. All amendments to the research protocol were submitted and approved. Conclusions: An objective and standardized diagnostic tool is needed for the personalized treatment of PD by traditional Korean medicine. Therefore, we developed a clinical index as the basis for the PI clinical evaluation of PD. Trial Registration: This trial is registered with the Clinical Research Information Service (CRIS) (KCT0008677)