• Nuclear Engineering and Technology
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• 제44권4호
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• pp.393-404
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• 2012

After the Fukushima nuclear accident in 2011, there has been increasing concern regarding severe accidents in nuclear facilities. Severe accident scenarios are difficult for operators to monitor and identify. Therefore, accurate prediction of a severe accident is important in order to manage it appropriately in the unfavorable conditions. In this study, artificial intelligence (AI) techniques, such as support vector classification (SVC), probabilistic neural network (PNN), group method of data handling (GMDH), and fuzzy neural network (FNN), were used to monitor the major transient scenarios of a severe accident caused by three different initiating events, the hot-leg loss of coolant accident (LOCA), the cold-leg LOCA, and the steam generator tube rupture in pressurized water reactors (PWRs). The SVC and PNN models were used for the event classification. The GMDH and FNN models were employed to accurately predict the important timing representing severe accident scenarios. In addition, in order to verify the proposed algorithm, data from a number of numerical simulations were required in order to train the AI techniques due to the shortage of real LOCA data. The data was acquired by performing simulations using the MAAP4 code. The prediction accuracy of the three types of initiating events was sufficiently high to predict severe accident scenarios. Therefore, the AI techniques can be applied successfully in the identification and monitoring of severe accident scenarios in real PWRs.

• 대한한방체열의학회지
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• 제1권1호
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• pp.38-46
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• 2002

1. Objectives Among many symptoms that the climacteric patients complain of, the major subjective symptom is both heat in the upper part and cold in the lower part of the body(e.g foot, knee, and leg). We use DITI as a method to prove the symptoms of climacteric patients such as both heat in the upper part and cold in the lower part of the body, diagnose these symptoms, and follow up the progress of the clinical treatments. 2. Subjects and Methods We compare the subcutaneous heat of the climacteric patients with the symptom of heat in the upper part and cold in the lower part of the body with young women without any specific disease. The age distribution of the experimental group is 28 patients in 40's, and 22 in 50's. The mean age of the experimental group is $48.5{\pm}4.25$. The age distribution of the control group is 17 patients in teen, 26 in 20's, 7 in 30's. The mean age of the control group is $23.31{\pm}6.45$. We measure the subcutaneous heat on the cheeks, upper arms, palms, thighs, knees, dorsum pedis, lower back, hip, upper abdomen, lower abdomen of both groups and analyse the results. 3. Statistical methods All the results are statiscally analysed using student T-test of Microsoft Exel program. Statistically significant value by the analysis of variance procedure is P<0.05. 4. Results 1. The subcutaneous heat of the whole body of the experimental group shows hypothermia compared with control group, and the hypothermic pattern gets severe on the periphery. ${\Delta}T$ between the right and left side of the body in experimental group is larger than that of control group. 2. ${\Delta}T$ between the cheeks and the hypogastric in the experimental group is significantly larger than that of the control group, which shows cold face. 3. ${\Delta}T$ between the upper arms and the palms in the experimental group is significantly larger than that of the control group, which shows cold hand. 4. ${\Delta}T$ between the thighs and the knees in the experimental group is significantly larger than that of the control group, which shows cold knee. 5. ${\Delta}T$ between the thighs and the feet in the experimental group is significantly larger than that of the control group, which shows cold foot. 6. ${\Delta}T$ between the hip and the lower back in the experimental group is significantly larger than that of the control group. That shows the Lower back is warmer than the hip. 7. ${\Delta}T$ between the upper and the lower abdomen in the experimental group is significantly larger than that of the control group, which shows cold hypogastric.

• 한국의류학회지
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• 제22권7호
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• pp.963-968
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• 1998

A study was conducted to investigate the effect of cooling hands of feet on human thermoregulation in the cold. Eight young (22$\pm$1 yr) and eight aged (69$\pm$4 yr) men volun-teered as subjects They stayed at 1$0^{\circ}C$ in the supine posture during the experiment which included hands or feet exposure to the air for 20 minutes. Hand Exposure (HE) and Foot Exposure (FE) were conducted in radomized order and the baseline was kept before HE and FE. Core temperatures, limb skin temperatures adn thermal sensations were measured. Obtained data were analyze using t-test and correlation. Rectal and esophageal tem-peratures increased in the young (YG) and in aged (AG). Change rate of esophageal temperature (Tes) was maintained higher during FE than HE while rectal temperature showed no differences between YG and AG, and between HE and FE. Hand and foot skintemperature in YG and AG decreased similarly during HE and Fe. Forearm skin temperature during HE decreased while leg skin temperature during FE showed no change HE and Fe. It was concluded that the lower cooling. Furthermore, the increase of Tes was greater in young men than aged men. It is also suggested that the wearing behavior can be differently modified between young and aged men.

• Nuclear Engineering and Technology
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• 제53권1호
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• pp.93-102
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• 2021

The analysis of the fluid flow characteristics in reactor pressure vessel is an important part of the hydraulic design of nuclear power plant, which is related to the structure design of reactor internals, the flow distribution at core inlet and the safety of nuclear power plant. The flow distribution and mixing characteristics in the pressurized reactor vessel for the 1000MWe advanced pressurized water reactor is analyzed by using Computational Fluid Dynamics (CFD) method in this study. The geometry model of the full-scaled reactor vessel is built, which includes the cold and hot legs, downcomer, lower plenum, core, upper plenum, top plenum, and is verified with some parameters in DCD. Under normal condition, it is found that the flow skirt, core plate holes and outlet pipe cause pressure loss. The maximum and minimum flow coefficient is 1.028 and 0.961 respectively, and the standard deviation is 0.019. Compared with other reactor type, it shows relatively uniform of the flow distribution at the core inlet. The coolant mixing coefficient is investigated with adding additional variables, showing that mass transfer of coolant occurs near the interface. The coolant mainly distributes in the 90° area of the corresponding core inlet, and mixes at the interface with the coolant from the adjacent cold leg. 0.1% of corresponding coolant is still distributed at the inlet of the outer-ring components, indicating wide range of mixing coefficient distribution.

• Nuclear Engineering and Technology
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• 제56권3호
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• pp.980-992
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• 2024

Steam line break accident (SLB) in the nuclear reactor is one of the representative Non-LOCA accidents in which thermal-hydraulics and neutron kinetics are strongly coupled each other. Thus, the multi-scale and multi-physics approach is applied in this study in order to examine a realistic safety margin. An entire reactor coolant system is modelled by system scale node, whereas sub-channel scale resolution is applied for the region of interest such as the reactor core. Fuel performance code is extended to consider full core pin-wise fuel behaviour. The MARU platform is developed for easy integration of the codes to be coupled. An initial stage of the steam line break accident is simulated on the MARU platform. As cold coolant is injected from the cold leg into the reactor pressure vessel, the power increases due to the moderator feedback. Three-dimensional coolant and fuel behaviour are qualitatively visualized for easy comprehension. Moreover, quantitative investigation is added by focusing on the enhancement of safety margin by means of comparing the minimum departure from nucleate boiling ratio (MDNBR). Three factors contributing to the increase of the MDNBR are proposed: Various geometric parameters, realistic power distribution by neutron kinetics code, Radial coolant mixing including sub-channel physics model.

• 사상체질의학회지
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• 제17권2호
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• pp.52-63
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• 2005

1. Objectives Due to a lack of detail guidelines for prescriptions to ordinary and pathological symptoms in ${\ulcorner}$DongyiSuseBowon${\lrcorner}$, doctors depend on their own decision when give a prescription. This study aimed to compare ordinary symptoms and pathological symptoms in regards to six prescriptions being applied to Soyangin to utilize them as guidelines in practices. 2. Methods Date were collected from September, 2003 to August, 2004 at the Sasang Constitutional clinic of Pohang Oriental Medicine Hospital. Patients were first asked to fill Out a questionnaire of symptoms that they had at the time of visiting. Data from 273 Soyangin patients whose chief complains got alleviated after taking the prescribed drug were analyzed to examine if there were differences in prescriptions according to ordinary or pathological symptoms complained. 3. Results and Conclusions 1. Hyungbangpaedog-san(Paedog) was given more to the patients having good digestive function than Hyungbangjihwang-tang(Hyungji) and Hyungbangdojeok-san (Dojeok) ; Dojeok was given for bloating symptom compared to Hyungbangsabaek-san(Sabaek). Yangkyuksanhwa-tang(Yangkyuk) and Dojeok were more like for patients with stomachache compared to Paedog. Doghwaljihwang-tang(Dogji) was prescribed to patients complaining frequent voiding compared to Sabaek while Sabaek was given for patients who prefer cold water and feel their body warm compared to other prescriptions. Yangkyuk and Dojeok were prescribed more likely to patients with feeling of suffocation than Sabaek. 2. In symptom comparisons between one prescription and the group of the rest of 5 prescriptions, Paedog was found to be prescribed when patients had good digestive function while Dojeok was given in symptoms cases of indigestion, bloating, constipation and dizziness. Sabaek was applied more for patients having tendency of preferring cold water and feeling of heat body as well as good digestive function. Hyungji was used for patients complaining a symptom of fatigue, in addition Yangkyuk was given to patients who were nervous, sensitive, or impatient when compared to Other prescriptions. Dogji was applied to frequent voiding, insomnia, tingling of extremities, backache or leg pain, or in case of tendency of catching a common cold.

• 한국의류산업학회지
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• 제1권1호
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• pp.43-49
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• 1999

This study conducted 4 different kinds of underwear materials, which were A (Cotton 100%), B (Wool 100%), C (Cotton/Wool, 50/50%) and D (Acrylic/Cotton, 50/50%) and were done in a climate chamber under cold ambient $10{\pm}1^{\circ}C$, $40{\pm}5%RH$ by 6 male subjects who were in good health. Physiological parameters such as rectal and local skin temperature(forehead, forearm, hand, trunk, thigh, leg, foot, back and chest), heart rate, body weight loss, clothing microclimate, blood lactic acid concentration, and wearing sensation were measured. Started with a 15-min rest period, 15-min of exercise 1 (the condition of 4.5 mile/hr walking speed equivalent to with 8.5 Kcal energy consumption on the treadmill) period, 15-min rest period, exercise 2 (after 3minutes warming-up at 3.0. 3.7, 4.5. 5.2. 6.0, 6.7 mile/hr) until exhaustion period, and final 15-min of recovery period were performed. The results were as follows: The lowest mean skin temperature was acrylic/cotton in order of wool > cotton/wool > cotton > acrylic/cotton (F=13. 79. p<0.00l). Most of all skin temperature by parts of body had turned out in sequence of temperature wool > cotton/wool > acrylic/cotton > cotton. Fore arm part showed highest temperature about $32.43^{\circ}C$ on wool and had a tendency approximately $1.8^{\circ}C$ higher than cotton which had the lowest temperature, and had the biggest difference among garments in terms of skin temperature. The back temperature within clothing showed about $2^{\circ}C$ higher than the chest temperature within clothing. but the back humidity within clothing showed about 4~12% higher than the chest humidity within clothing. Body weight loss by each garment was this sequence; cotton > acrylic/cotton > wool > cotton/wool.

• The Journal of Korean Physical Therapy
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• 제12권2호
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• pp.107-119
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• 2000

This study is fulfilled from September 1st to December 31st in 1999 and the object of investigation are all 289 students belong to 5 universities managing amateur Ssirum team in Kyungnam, Kyungpook. Pusan and Seoul(158 people) and 6 high schools(131 people). And these results were derived from percentage and cross analysis of Person Chi-square test ann interview and 47 questioned paper based on this purpose of study. 1. There were no significant differences between high school students and university students in the comprehension of physical therapy and injury occurrence by technique. 2. According to the relation between satisfaction of life as a player and injured part, the injury of soft tissue ranked high among satisfied and unsatisfied people. and the satisfaction or unsatisfaction of practicing place also derived same result. 3. $46.8\%$ of Ssirum players got the injury of soft tissue during practice. the articular injury and bone injury in regular sequence. But there were no relations between the time of injury and the sort of injury. 4. There were no statistical differences ortho sort of injury by technique.(p=0.399). 5. According to the part of injury by using techniques, the injury of soft tissue ranked high$(50.0\%)$, articular injury ranked high$(42.6\%)$ in the leg technique, bone injury ranked high in the leg technique, and nerve injury ranked high in hand technique. 6. The injury of soft tissue ranked high during the practice$(46.8\%)$, practice on the purpose of a match$(50.0\%)$ and match$(41.7\%)$ but there were no relations between the time of injury and son of injury. 7. The part of injury by technique ranked high in the soft tissue$(50.0\%)$, articular injury by leg technique$(42.6\%)$, bone injury in leg and waist technique and nerve injury in hand technique high. 8. The time of injury ranked high during the practice$(65.7\%)$, and $66.1\%$ of injury occurred in the afternoon. 9. During the practice, the cold weather ie related on the rate of injury because $67\%$ of injury occurred in winter, but there are no statistical significance. 10. There were no relations between the satisfaction of place far practice and time of injury. 11. The particular part of injury occurred very much during the match between defense and offense. 12. In the relation between the degree of understanding of physical therapy and the experience of physical therapy, the people who know physical therapy had much experiences of physical therapy(p=.000) And independent of the physical therapy experiences, the effectiveness of physical therapy therapy to players was $48.8\%$, no idea was 42.65 and no effectiveness was $8.7\%$(p=.000). 13. $59.6\%$ of the people admitting the physical therapy effectiveness answered they would follow the order of the doctor and $56.6\%$ of the people not admitting the physical therapy effectiveness answered no.

• 한국원자력학회:학술대회논문집
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• 한국원자력학회 1996년도 춘계학술발표회논문집(2)
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• pp.23-28
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• 1996

The potential for the RELAP5/MOD3.2 was assessed for the loss-of-RHR event during the mid-loop operation and the predictability of major thermal-hydraulic phenomena was also evaluated for the long term transient. The analysis results of the typical two cases(cold leg opening case and pressurizer opening case) were compared with experimental data which was conducted at ROSA-IV/LSTF in Japan. As a result, it was shown that tile code was capable of simulating the thermal-hydraulic transport process with appropriate time step during the reduced inventory operation with the loss-of- RHR system.

• 한국원자력학회:학술대회논문집
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• 한국원자력학회 1997년도 춘계학술발표회논문집(1)
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• pp.551-556
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• 1997

A present study addresses a loss-of-RHR event as an initiating event under specific low power or shutdown conditions. Two typical plant configurations, cold leg opening case with water-filled steam generators and pressurizer opening case with emptied steam generators, were evaluated using the RELAP5/ MOD3.2 code. The calculation was compared with the experiment conducted at ROSA-IV/LSTF in Japan. As a result, the code was capable of simulating the system transient behavior following the event. Especially, thermal hydraulic transport processes including non-condensable gas behavior were reasonably predicted with an appropriate time step and CPU time. However, there were some code deficiencies such as too large system mass errors and severe flow oscillations in core region.