• 대한기계학회논문집
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• 제18권2호
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• pp.467-478
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• 1994

This paper deals with dynamic behaviors of a free-piston Vuilleumier heat pump system, which are characterized by stroke of each diplacer/stroke ratio, operating frequency and phase angle. Based on the Isothermal Model, basic equations of motion are derived and linearized. In particular, dependence of damping coefficients of the dynamic parameters are taken into account in the formulation, which does not bring additional difficulties in the analysis. In order to investigate effects of design conditions on the dynamic parameters are taken into account in the formulation, which does not bring additional difficulties in the analysis. In order to investigate effects of design conditions on the dynamic characteristics, calculations are performed for the prototype made by Schulz and Thomas and results are qualitatively compared with their data obtained from the analysis as well as the experiment. It appears that they made a mistake in evaluating the hysteresis loss of the gas spring in their analysis. And, the present results show a better agreement with their experimental data than those by their own analysis. Although there are some unresolved aspects such as frequency variations with respect to the mean pressure and the hot space temperature, it is expected that the present analysis may be an effective tool for prediction of dynamics of a free- pistion VM machine at the preliminary design stage.

• International Journal of Automotive Technology
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• 제8권5호
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• pp.543-553
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• 2007

It is becoming increasingly difficult for engines using conventional fuels and combustion techniques to meet stringent emission norms. The homogeneous charge compression ignition(HCCI) concept is being evaluated on account of its potential to control both smoke and NOx emissions. However, HCCI engines face problems of combustion control. In this work, a single cylinder water-cooled diesel engine was operated in the HCCI mode. Diesel was injected during the suction stroke($0^{\circ}$ to $20^{\circ}$ degrees aTDC) using a special injection system in order to prepare a nearly homogeneous charge. The engine was able to develop a BMEP(brake mean effective pressure) in the range of 2.15 to 4.32 bar. Extremely low levels of NOx emissions were observed. Though the engine operation was steady, poor brake thermal efficiency(30% lower) and high HC, CO and smoke were problems. The heat release showed two distinct portions: cool flame followed by the main heat release. The low heat release rates were found to result in poor brake thermal efficiency at light loads. At high brake power outputs, improper combustion phasing was the problem. Fuel deposited on the walls was responsible for increased HC and smoke emissions. On the whole, proper combustion phasing and a need for a well- matched injection system were identified as the important needs.

• Korean Journal of Acupuncture
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• 제41권2호
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• pp.43-50
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• 2024

Objectives : Samanhyeol is a combination of acupoints located in the cubital and popliteal fossa. It is commonly used in clinical practice to treat acute illnesses such as summerheat stroke, vomiting, diarrhea, and hemorrhagic diseases. There are two types of Samanhyeol in literature: BL40 and LU5, and BL40 and PC3. We investigated which acupoint is representative of Samanhyeol, and more closely fits the definition of Samanhyeol between LU5 and PC3. Methods : We searched for literature related to Samanhyeol, compared the anatomical locations of LU5, PC3, and BL40, examined their indications associated with the effectiveness of Samanhyeol, and checked cases in the literature where LU5 or PC3 was used concurrently with BL40. Results : BL40, one of the Samanhyeol, has been used to treat summerheat stroke, vomiting, diarrhea, and epistaxis in acupuncture texts, and there are many references in the literature to BL40 being used for bloodletting. And BL40 is located in the midpoint of the traverse crease of the popliteal fossa. From this perspective, LU5 may be a more suitable than PC3 because it is located in the midpoint of the cubital crease. However, Samanhyeol is a combination of acupoints used to treat heat stroke, vomiting and diarrhea, and hemorrhagic diseases. Upon analyzing the literature, it was found that LU5 and PC3 have similar efficacy. However, PC3 was used more frequently in cases of severe fever, unconsciousness or syncope. Conclusions : Literature suggests that BL40 is the representative acupoint for Samanhyeol. And PC3 is more appropriate than LU5 for Samanhyeol because its effects are more stronger on heat stroke although both LU5 and PC3 can treat symptoms related to Samanhyeol.

• Journal of Preventive Medicine and Public Health
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• 제53권1호
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• pp.26-28
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• 2020

In September 2018, heat waves were declared to be a type of natural disaster by the Framework Act on the Management of Disasters and Safety. The present study examined the characteristics of heat waves from the perspectives of meteorological phenomena and health damage. The government's efforts to minimize the damages incurred by heat waves are summarized chronologically. Furthermore, various issues pertaining to heat waves that are being raised in our society despite the government's efforts are summarized by analyzing big data derived from reported news and academic articles.

• 한국자동차공학회논문집
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• 제4권1호
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• pp.208-217
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• 1996

Instantaneous surface temperature and unsteady heat flux of intake and exhaust valve in methanol fueled engine were investigate as a function of compression ratio and engine speed. To accomplish this purpose, the instantaneous temperature sensor was designed and it was installed into three point of intake and exhaust valve head to measure unsteady temperature. The unsteady heat flux at valves was evaluated using one dimensional heat conduction equation with the valve head temperature and temperature gradient. And also mean heat flux of intake and exhaust valve for each stroke were evaluated as a function of engine speed.

• 동의생리병리학회지
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• 제22권2호
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• pp.453-458
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• 2008

This study aimed to develop an evaluation reliability of Korean pattern identification for wind stroke. We studied 643 patients with stroke and made a list of registry for each of them. The present study analyzed 553 cases, in which the resident’s pattern identification agreed with the specialist’s one, and the cases included five differentiation pattern: the fire-heat pattern (114), the dampness-phlegm pattern (157), the static blood pattern (11), the Yin deficiency pattern (81), and the Qi deficiency pattern (190). This study showed that none of the Cronbach's alpha reached 0.700, which is the general reliable level. The average Cronbach's alpha of each symptoms was 0.353 for the dampness-phlegm pattern, 0.571 for the fire-heat pattern, 0.443 for the Qi deficiency pattern, 0.451 for the Yin deficiency pattern, and 0.302 for the static blood pattern. This suggests the possibility that each pattern identification could be coincided with other symptoms, and it also shows the limits of pattern identification of this study that narrows the symptoms of paralysis patients into only a single pattern. Continuous compliments and researches should be done referring to this matter. However, the internal consistency analysis of all the pattern identification showed that every Cronbach's alpha were within the range of 0.670 to 0.703, and the Cronbach's alpha of the whole symptoms was evaluated as 0.692, which makes the reliability of the pattern identification as itself almost satisfactory to the general reliable level, and therefore, significant. In the future, continuous clinical research to develope this pattern identification for wind stroke actually applicable to stroke patients needs to be made through accumulating more cases, improving the objectivity.

• 한국한의학연구원논문집
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• 제11권1호
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• pp.109-118
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• 2005

In a field of oriental medicine, it is necessary to collect systemically clinical data and integrate. Input data items was decided, then categorized by the modules through discussion of the institute and hospitals. Items are information of patient, history, aspects of occurrence, pattern identification, prescriptions of herbal medicine, the results of biochemical serum examination, blood cell count, urine analysis, CT, MRI, Chest PA, EKG etc. Factors in oriental medicine are Sasang constitution, Stroke-Pattern-Identification(china), differentiation of cold and heat syndrome. This tool was constructed by using Microsoft-Access 2000 and Microsoft Visual Basic 6.0. Furthermore this web-based system could be applied to multi-center clinical investigation.

• 대한중풍순환신경학회지
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• 제13권1호
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• pp.118-125
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• 2012

Object : The purpose of this study is to evaluate the effect of Hwangryunhaedok-tang herbal-acupuncture therapy for Agitation(Byun-jo) caused by cerebral infarction. Methods : One patient was admitted who was suffering from insomnia, chest discomfort, anxiety, palpitation of Agitation(Byun-jo), after cerebral infarction. In the point of Differentiation of Syndromes(辨證), we diagnosed this patient as Excessive heat-fire syndrome of stroke(中風火熱證) and treated with Hwangryunhaedok-tang herbal-acupuncture therapy at CV17, BL15, GB20. Results : After Hwangryunhaedok-tang herbal-acupuncture therapy, symtoms of Agitation(Byun-jo) were improved remarkably, and the score of State-Trait Anxiety Inventory(STAI), Pittsburgh Sleep Quality Index(PSQI) were decreased. Conclusions : Hwangryunhaedok-tang herbal-acupuncture therapy has meaningful effect on the symptoms of Agitation(Byun-jo) caused by cerebral infarction and more researches should be followed.

• 동의생리병리학회지
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• 제22권2호
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• pp.469-480
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• 2008

This study was performed to investigate using of herbal medicine based on pattern identification of symptoms, such as Qi deficiency pattern, Yin deficiency pattern, Phlegm -dampness pattern, Static blood pattern, Fire-heat pattern. These patterns settled by Korean Standard Differentiation of the Symptoms and Signs for Stroke in 2005. This study was done with 177 patients in Daejeon University Oriental Medical Hospital in the period of November 2006 to July 2007. Among the five types of pattern identification, Phlegm -dampness pattern showed significantly high frequency especially in 3 weeks after stroke. The sort of herbal medicine was 43 and Dodamhwalhyoel-tang(26.61%), Sunhwanki 1 hobang(14.52%), Banhabaekchulcheonma-tang(4.84%), Ansinchongnoi-tang(4.84%), Chongryuldodam-tang(4.03%) were most frequently used. Especially Dodamhwalhyoel-tang showed significantly high frequency in 2 weeks after stroke. Based on these results, it is suggested that more practical Korean Standard Differentiation of the Symptoms and Signs for Stroke would be established through continuous clinical studies by giving weight on relationship between herbal medicine and pattern identification.

• 동의생리병리학회지
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• 제20권6호
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• pp.1789-1792
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• 2006

To develop the Korean Standard Differentiation of the symptoms and signs for the Stroke(KSDS), the committee on Stroke Diagnosis Standardization of Korean Traditional Medicine was organized by nineteen experts in College of Korean Medicine, The Consensus of the second Consultation Meeting was as follows : First is the definition of the stroke on the Korean Traditional Medicine. Second is the five categories to the Differentiation of the symptoms and signs for the Stroke - fire and heat, dampness and phlegm, blood stasis, qi deficiency, yin deficiency. Third is the indices of the Differentiation of the symptoms and signs for the Stroke respectively. KSDS-1 will be applied to the clinical practice and revised. The Consensus of the third Consultation Meeting had agreed 81 symptoms indexes of KSDS.