• 제목/요약/키워드: Cold-Heat

검색결과 1,978건 처리시간 0.027초

Theory study on thermal performance of metal foam

  • Jin, Meihua;Kim, Pil-Hwan;Lee, Hae-Jong;Jeong, Hyo-Min;Chung, Han-Shik
    • 대한설비공학회:학술대회논문집
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    • 대한설비공학회 2008년도 동계학술발표대회 논문집
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    • pp.239-243
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    • 2008
  • In many literatures the researchers pointed out that the using metal foam will significantly enhance the performance of heat exchanger. This paper focuses on theory study of metal foam, including calculation method of properties of foam (permeability ��K, inertial coefficient f, fiber diameter $d_f$, and effective conductivity $k_e$), model of pressure drop and model of heat transfer. Theory analysis on the performance of heat exchanger will be presented here. Finally the optimal material will be obtained from theory calculation.

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건강인의 표리 한열 변증, HRV, 우울, 불안 지표의 상관성 분석 (Relationships between depression, anxiety, 'exterior-interior pattern and cold-heat pattern' and Heart Rate Variability in healthy Subjects)

  • 김지은;이정찬;강희철;이승기;박경모
    • 동의생리병리학회지
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    • 제20권2호
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    • pp.482-487
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    • 2006
  • The identification of the exterior-interior pattern and the cold-heat pattern is one of the most frequently used diagnostic methods in Oriental medicine. No systematic studies, however, have yet been conducted to determine the emotional and autonomic factors involved in the exterior-interior and cold-heat. In this study, the relationships between depression, anxiety, and the exterior-interior and cold-heat patterns in 100 healthy female volunteers with a mean age of 42.77 were also investigated. The autonomic nervous system's control of human temperature is a well known fact. Thus, this paper also aimed to investigate the correlationof the autonomic nervous system and patterns of the exterior-interior and cold-heat. The analysis of heart rate variability (HRV), which has become a popular non-invasive tool for assessing the activities of the autonomic nervous system, was conducted in this study. No relationship was found between the exterior-interior and cold-heat pattern scores and the degree-of-depression scores. But there was a significant difference between the exterior-interior and cold-heat pattern scores of the different anxiety types, and between those of the different anxiety levels. The depression and anxiety levels also had an effect on the HRV indices.

사상의학 병증진단에 있어서 사상의학 전문가의 한열 특성 및 건강상태 평가에 관한 일치도 연구 (The Agreement in Cold-Heat and Health Status among Sasang Constitutional Experts in Diagnosis of Sasang Pathological Symptoms)

  • 진희정;김상혁;동상옥;장은수;이시우
    • 사상체질의학회지
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    • 제26권2호
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    • pp.146-155
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    • 2014
  • Objectives In Sasang Constitutional medicine(SCM), it is an important factor to assess the degree of cold/heat and healthy status. We purposed to check the agreement among the experts on the assessment of cold/heat and healthy status. Methods Six SCM experts and 10 healthy volunteers were recruited for this study. The SCM experts had an interviewed with each volunteer in the similar condition like that of the actual clinic. And then the expert evaluated each volunteer's cold/heat and healthy status. Intraclass correlation coefficient(ICC) was used to measure the interrater reliability and interrater agreement among the experts. Results Two volunteers are excluded due to the missing data, therefore eight persons' data (3 males and 5 females) were included in our analysis. The mean of age and BMI are 21.73(${\pm}2.32$) and 29.63(${\pm}4.66$), respectively. In health status, cold status and heat status, the ICC was 0.789, 0.904, 0.925, respectively. Conclusions We found that the assessment of cold/heat and healthy status was continued reliable among SCM experts. The assessment of cold/heat status was more consistent than the assessment of healthy status.

팔강변증의 진단율 향상을 위한 형색맥증진단(形色脈證診斷)시스템 설계 - 한열변증을 중심으로 - (Proposal of Form-Color-Pulse-Symptom Diagnostic System for Enhancement of Diagnostic Rate of 8 Principle Pattern Identification - Focusing on Cold Heat Pattern Identification -)

  • 지규용;이인선;전수형;김종원
    • 동의생리병리학회지
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    • 제33권3호
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    • pp.163-168
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    • 2019
  • In order to enhance the 8 principle pattern diagnosis rate comparing with diagnostic method by self-report questionnaire on cold/heat pattern in the clinical practice, a new diagnostic method using form-color-pulse-symptom (FCPS) system is proposed. FCPS system is composed of outputs of cold/heat pattern through the calculation process of contribution degree to the cold, heat pattern and qi, blood, yin, yang deficiency patterns, based on analysis of 16 mechanisms of disease calculated by diagnostic system of oriental medicine (DSOM) first. And second component is an output of differentiated 8 principle patterns in detail through binding and calculating process with digital informations of pulse, color, form, constitution obtained by computerized measurement system. Putting together above two processes consecutively, cold-heat complex or true/false cold/heat patterns and personalized characters of cold/heat patterns of each patient can be subdivided through a computation method of determining each pattern. In conclusion, 8 principle pattern identification can be performed more accurately using FCPS system than existent self report questionnaire method. These hypothetic proposal is needed to be proven by clinical trial for the future and then the accurate numbers used in each calculational function should be revised properly.

Association between cold-heat symptoms and sleep disturbances according to the Sasang constitution: a cross-sectional community study

  • Hyun, Min Kyung;Yoshino, Tetsuhiro
    • 대한예방한의학회지
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    • 제26권1호
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    • pp.59-74
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    • 2022
  • Objectives : Evidence supporting the cold-heat symptom and sasang constitution type, which are diagnostic items of traditional Korean medicine, is needed to manage sleep disturbances, which is a typical symptom of mibyeong (subhealth). This study examined the association between each cold-heat symptom and sleep disturbances according to each sasang constitution type. Methods : This research was a cross-sectional study of 5,793 subjects from the Korean Medicine Data Center (KDC) community cohort survey. The association between each cold-heat symptom and sleep disturbances was analyzed by logistic regression analysis adjusted for several demographic variables. Subgroup analysis was then performed for each type of sasang constitution. Results : The soeum and soyang types were 1.53 and 1.26 times more likely to have sleep disturbances than the taeum type. Sleep disturbances were associated with 'coldness of the abdomen', 'watery mouth' in the cold domain items, and 'body feverishness', 'flushed face and eye', 'thirst', and 'scanty dark urine' in the heat domain items. The soeum and soyang types were 1.55 and 1.39 times more likely to sleep less than five hours per night than the taeeum type. In addition, the associations of those showed a different pattern for each sasang constitution type. Conclusions : Sleep disturbances are associated with specific cold-heat symptoms, and the associated cold-heat symptoms differ according to the sasang constitution type. These results may help traditional medicine specialists select customized interventions for patients with sleep disturbances.

가용에너지를 이용한 대향류 열교환기의 해석 (Analysis of Counterflow Heat Exchangers with the Concept of Available Energy)

  • 김수연;정평석
    • 대한기계학회논문집
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    • 제16권11호
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    • pp.2189-2195
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    • 1992
  • 본 연구에서는 대향류 열교환기에 대하여 출력과 효율 등을 계산하는 예를 보 이고, 동시에 최대의 출력을 얻기 위한 조건들을 수치적으로 구하였다. 또한 열교환 기의 장치비용과 열원의 생성비용을 적절히 취급하여 경제적 최적조건에 대해서도 살 펴보고자 한다. 여기서 저온유체의 가용 에너지 획득량으로서 출력은 열전달로 인한 부분만을 생각하기로 한다.

한반도 겨울철 한파와 관련된 대기 순환과 열원의 특성 (Characteristics of Atmospheric Circulation and Heat Source related to Winter Cold Surge in Korea)

  • 김맹기;신성철;이우섭
    • 한국지구과학회지
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    • 제26권6호
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    • pp.560-572
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    • 2005
  • 이 연구에서는 1979년부터 1999년까지 21년 동안에 한반도 겨울철 한파와 관련된 대기 순환 및 열원$(Q_1)$의 분포 특성을 조사하였다. 한파 발생 빈도는 1년간 약 1개로 나타났으며, 1989년을 중심으로 전반기에 전체의 $60\%$가 발생하였다. 한파 발생 동안 하층의 대기 순환 패턴은 평년에 비해 서고동저형의 기압 패턴이 더 뚜렷하며, 상층에서도 한반도에 기압골의 영향이 더 강하게 나타난다. 한파가 발생하는 동안에 한반도 부근의 기온 하강 패턴은 바이칼호 부근의 기온 패턴과 반대로 나타나며, 기온의 연직 구조에서도 400 hPa을 기준으로 하층과 상층의 기온 편차는 반대로 나타난다. 열원에 대한 분석은 한파 발생 시 한랭 이류에 의한 냉각은 하강 운동에 의한 단열 승온에 의해 균형을 이룬다는 것을 보여주는데, 이것은 한랭 핵의 이동이 열흡수원의 이동 경로와 연관되어 있음을 나타낸다. 따라서 한파의 유지 기작을 이해하고 한파를 예측하기 위해서는 열원 그리고 열흡수원의 이동 기작이 밝혀져야 할 것이다.

얼음 미시물리 과정이 도시 열섬이 유도하는 대류와 강수에 미치는 영향 (Influences of Ice Microphysical Processes on Urban Heat Island-Induced Convection and Precipitation)

  • 한지영;백종진
    • 대기
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    • 제17권2호
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    • pp.195-205
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    • 2007
  • The influences of ice microphysical processes on urban heat island-induced convection and precipitation are numerically investigated using a cloud-resolving model (ARPS). Both warm- and cold-cloud simulations show that the downwind upward motion forced by specified low-level heating, which is regarded as representing an urban heat island, initiates moist convection and results in downwind precipitation. The surface precipitation in the cold-cloud simulation is produced earlier than that in the warm-cloud simulation. The maximum updraft is stronger in the cold-cloud simulation than in the warm-cloud simulation due to the latent heat release by freezing and deposition. The outflow formed in the boundary layer is cooler and propagates faster in the cold-cloud simulation due mainly to the additional cooling by the melting of falling hail particles. The removal of the specified low-level heating after the onset of surface precipitation results in cooler and faster propagating outflow in both the warm- and cold-cloud simulations.

한열(寒熱) 변증에 따른 한의 외용 치료제 비염고의 치료 효과 : 하위 그룹 분석 (Effectiveness of herbal ointment Biyeom-go according to cold-heat pattern identification: a subgroup analysis on patients with rhinitis)

  • 손미주;이동효
    • 한방안이비인후피부과학회지
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    • 제32권4호
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    • pp.29-40
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    • 2019
  • Objectives : Hwanglyeonhaedok-tang(黃連解毒湯) is a representative herbal formula with "clear heat(淸熱)" effects. The aim of this study was to evaluate the effects of Hwanglyeonhaedok-tang-based intranasal herbal ointment Biyeom-go based on the cold and heat pattern identification questionnaire(CHPIQ). Methods : We performed a subgroup analysis of the previously published prospective observational study. A total of 58 patients with rhinitis were administered Biyeom-go for 4 weeks, and its effects on the Total Nasal Symptom Score(TNSS), Mini Rhinoconjunctivitis Quality of Life Questionnaire(Mini-RQLQ) score, and nasal endoscopy index score were analyzed based on CHPIQ. Results : Among the 58 patients, the heat and non-heat patterns were shown by 39 and 19 patients, respectively, while the cold and non-cold patterns were shown by 46 and 12 patients, respectively. The change in TNSS from baseline negatively correlated with the heat pattern score(p=0.011). Improvement in TNSS was greater in the heat pattern group than in the non-heat pattern group, with a borderline significant difference(p=0.07). Mini-RQLQ and nasal endoscopy index scores tended to be lower in the heat pattern group than in the non-heat pattern group, but without a statistically significant difference. Conclusion : The findings indicate that CHPIQ is a useful tool for the diagnostic and prognostic evaluation of patients with rhinitis. This study provides fundamental evidence of the close association between the cold-heat pattern in patients with rhinitis and the treatment effects of Biyeom-go.

베어링강 SUJ2의 냉간 단조성 향상을 위한 열처리에 관한 연구 (A Study on Heat Treatment for Improving Cold Forgeability of a Bearing Steel, SUJ2)

  • 김해지
    • 한국기계가공학회지
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    • 제8권1호
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    • pp.24-30
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    • 2009
  • In this paper, the effect of heat treatment on forgeability is investigated and an improved heat treatment cycle is proposed for the bearing steel, SUJ2. An application example of a bearing inner race cold forging, which has small cracks in the bottom after backward extrusion and piercing, is found from a cold forging industry. The process is evaluated by finite element analysis and several heat treatment cycles are examined in order to propose an improved heat treatment cycle. The effect of heat treatment on material hardness and tool life, dimensional accuracy and forming load is revealed through experiment.

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