• Title/Summary/Keyword: cold period

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Characteristics of Concrete Strength Development Based on Cement Type and Curing Temperature in Cold-Weather Conditions (한중조건에서 시멘트 종류 및 양생온도별 콘크리트의 강도 발현 특성)

  • Han, Jun-Hui;Lim, Gun-Su;Lee, Hyeon-Jik;Park, Jae-Woong;Kim, Jong;Han, Min-Cheol
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2023.11a
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    • pp.153-154
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    • 2023
  • In this study, analyzed the difference in compressive strength of concrete under cold conditions, using the 28-day standard curing compressive strength as a reference and examining variations based on cement types and curing temperatures. The results showed that the strength difference based on curing temperatures reached up to 9MPa at 0℃. However, as the curing period progressed, the difference in strength due to curing temperature gradually diminished. These findings are anticipated to be valuable for concrete mixing and quality control in cold weather conditions.

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A wear-leveling improving method by periodic exchanging of cold block areas and hot block areas (Cold 블록 영역과 hot 블록 영역의 주기적 교환을 통한 wear-leveling 향상 기법)

  • Jang, Si-Woong
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2008.05a
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    • pp.175-178
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    • 2008
  • While read operation on flash memory is fast and doesn't have any constraints, flash memory can not be overwritten on updating data, new data are updated in new area. If data are frequently updated, garbage collection, which is achieved by erasing blocks, should be performed to reclaim new area. Hence, because the number of erase operations is limited due to characteristics of flash memory, every block should be evenly written and erased. However, if data with access locality are processed by cost benefit algorithm with separation of hot block and cold block, though the performance of processing is high, wear-leveling is not even. In this paper, we propose CB-MG (Cost Benefit between Multi Group) algorithm in which hot data are allocated in one group and cold data in another group, and in which role of hot group and cold group is exchanged every period. Experimental results show that performance and wear-leveling of CB-MG provide better results than those of CB-S.

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Diagnostic Significance of Cold Agglutinin and Antimycoplasma Antibody for Mycoplasma pneumoniae Infection (항Mycoplasma 항체와 한냉응집소에 의한 Mycoplasma pneumoniae의 진단학적 의의)

  • Kim, Chung-Sook;Lee, Chae-Hoon;Jeon, Chang-Ho;Bae, Eun-Kyung;Hong, Seak-Il
    • Journal of Yeungnam Medical Science
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    • v.4 no.1
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    • pp.97-103
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    • 1987
  • A Study to evaluate the diagnostic significance of M. pneumoniae infection by measurements of cold agglutinin and antimycoplasma antibody titers is performed with 191 pediatric patients who have visited Yeungnam University Hospital during the period through January to July, 1987. Forty eight of 191 cases made follow up tests feasible. The results obtained are as follows : 1. It is necessary to perform routine combined measurements of cold agglutinin and antimycoplasma antibody titers for the all pediatric pneumoniae caser since a large proportion of pneumonia in children is caused by M. pneumoniae. 2. For the diagnosis of M. pneumoniae infection, measurements of cold agglutinin titers alone seems to be les significant than to check both cold agglutinin and antimycoplasma antibody titers. 3. The measurement of antimycoplasma antibody titer appeared to be more specific than cold agglutinin test in the diagnosis of M. pneumoniae infection. 4. The present study urges the necessity of follow up study of cold agglutinin and antimycoplasma antibody titers for those who initially presented with normal titers in both tests, but are clinically suspected for M. pneumoniae infection.

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The Clinical Study in Children with Common Cold (in summer & winter) (하절기(夏節期)와 동절기(冬節期)의 감모환아(感冒患兒)에 대한 임상적(臨床的) 고찰(考察))

  • Koo, Jin-Suk;Baek, Jung-Han
    • The Journal of Pediatrics of Korean Medicine
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    • v.16 no.2
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    • pp.101-110
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    • 2002
  • The common cold is the most common pediatric infectious disease and occupies a great number of outpatients in oriental pediatrics. Because children's common cold has characteristic symptoms, we studied 276 children suffering from common cold Oriental Medicine Hospital in Kyungsan University and analyzed sex, age, chief complaints, characteristic symptoms.(period : summer 2001. 6.1.-2001.8.31, winter 2001.12.1-2002. 2. 28) The results were as follows : 1. Male to female ratios were 17: 1 in summer, 1.2: 1 in winter, 1.4: 1 in total 2. Age distribution of children from 0 to 1 was 20.29%, from 1 to 3 was 39.49%, from 3 to 6 was 32.97%, from 6 to 10 was 7.27%, over 10 was 0%, from 0 to 6 was 92.75%. 3. Frequency of chief complaints In summer : cough was 22.28%, nasal discharge was 18.39%, fever was 16.58%, secretion and sputum were 14.50%, sweating was 6.99%, nausea or vomitting were 4.92% etc. In winter : cough was 24.20%, nasal discharge was 18.03%, secretion and sputum were 16.43%, occlusion of nares was 11.64%, fever was 9.58%, nausea or vomitting were 3.88% etc. Frequency of chief complaints has seasonal difference. 4. Children's common cold has characteristic symptoms and seasonal difference. 5. Children's common cold has characteristic clinical subtype.

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A method for improving wear-leveling of flash file systems in workload of access locality (접근 지역성을 가지는 작업부하에서 플래시 파일시스템의 wear-leveling 향상 기법)

  • Jang, Si-Woong
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.12 no.1
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    • pp.108-114
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    • 2008
  • Since flash memory cannot be overwritten, new data are updated in new area. If data are frequently updated, garbage collection which is achieved by erasing blocks, should be performed to reclaim new area. Hence, because the count of erase operations is limited due to characteristics of flash memory, every block should be evenly written and erased. However, if data with access locality are processed by cost benefit algorithm with separation of hot block ad cold block though the performance of processing is hight wear-leveling is not even. In this paper, we propose CB-MB (Cost Benefit between Multi Bank) algorithm in which hot data are allocated in one bank and cold data in another bank, and in which role of hot bank and cold bank is exchanged every period. CB-MB shows that its performance is 30% better than cost benefit algorithm with separation of cold block and hot block its wear-leveling is about a third of that in standard deviation.

A Review of Acupuncture Treatment Methods for Cold Hypersensitivity of Hands and Feet (수족냉증의 침 치료법에 대한 고찰)

  • Choi, Su-Ji;Choi, YunSeok;Lee, Yeon Sun;Noh, Eun-Ji;Kim, Dong-Il
    • Korean Journal of Acupuncture
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    • v.38 no.2
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    • pp.43-61
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    • 2021
  • Objectives : The purpose of this study is to review the acupuncture treatment for cold hypersensitivity of hands and feet. Methods : We searched articles in 7 search engines with keywords related to 'Cold hypersensitivity of hands and feet' and 'Raynaud disease' in March 2021. Clinical studies that used acupuncture for cold hypersensitivity of hands or feet were included. Animal studies and nonclinical data were excluded. Data on acupuncture treatment such as methods, site, duration, frequency, and period were analyzed. Also, network analysis between acupoints was conducted. Results : Of 41 selected articles, there were 32 case reports, 7 randomized controlled trials, and 2 uncontrolled clinical studies. Studies were conducted using manual acupuncture, electroacupuncture, warm needling, pharmacopuncture, fire needling, and auricular acupuncture. Most studies used more than one acupoint (n=40), and there were 111 acupoints selected for acupuncture treatment for cold hypersensitivity of hands and feet. The most commonly used acupoint was LI11 (n=27). In terms of the correlation of acupoints, LI11 had the highest value of degree centrality at 0.6989. The mean treatment time, number of treatments, and duration were 26.8±8.87 minutes, 15.51±15.75 times, and 77.69±132.80 days. Conclusions : The results of this study could be useful in establishing the evidence for performing standardized acupuncture treatment for cold hypersensitivity of hands and feet.

A Study on Effect and Satisfaction of Acupoint Sticking in Hottest Period of Summer (삼복첩의 치료 효과와 만족도에 대한 연구)

  • Song, Ji Hyun;Lee, Jin Hwa;Kim, Yun Hee
    • The Journal of Pediatrics of Korean Medicine
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    • v.32 no.1
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    • pp.1-10
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    • 2018
  • Objectives The purpose of this study is to understand effect on respiratory disease and satisfaction of parents about acupoint sticking in hottest period of summer. Methods A survey was conducted to the parents of their children who took acupoint sticking in Dog-days for two years in a row. 17 children (10 boys, 7 girls, 4.0-12.11 years) were attached Socheongo to BL-13, BL-15, BL-17 for 3 hours. In terms of the effectiveness of the therapy, the treatment only considered as effective when there is any improvement in respiratory symptoms. Results 11 children (64.7%) from the study group have shown positive effect. There were significant improvements in frequency of having a cold or duration of a cold; duration of rhinitis; frequency of having empyema or its duration; frequency of having bronchitis; frequency of having pneumonia; frequency of having otitis media. Respiratory health VAS (Visual Analog Scale) had significant increase from 5 to 6.71 (p<0.05). 7 parents (41.2%) were satisfied with acupoint in hottest period of summer and 16 parents (94.1%) wanted to have their children get treated again in next year. From the survey, inconveniences of acupuncture were weak attachment of the acupoint (23.5%), long attaching time (11.8%), pressure about number of treatments (5.9%), worry about side effects (5.9%). Side effects have been reported; 2 pruritus (11.8%), 1 pruritus and erythema (5.9%). Conclusions Acupoint sticking in hottest period of summer improves lung symptoms in children older than three years old. However, the ways to reduce the side effects and inconveniences are needed.

Experimental Study on Natural Ventilation Performance of Double Facade System in Heating Period (난방기 중 이중외피 시스템의 자연환기 성능분석에 관한 실험적 연구)

  • Lee, Keon-Ho;Kim, Hyeon-Soo;Ko, Yung-Woo;Son, Young-Joo
    • KIEAE Journal
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    • v.6 no.2
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    • pp.43-50
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    • 2006
  • A Double Facade System(DFS) is well known as an innovative solution of ecological facade in the west european countries. There are more than 200 various realized DFS in Germany. At the same time, the korean engineers have researched to find out the physical advantages of DFS in the moderate korean climate, which has a very humid summer with high temperature and a dry winter with low temperature. For example, the monthly mean temperature in Korea comes up to 28K, while that in Germany comes up to only 19K. That is, why a other solution of DFS is needed in Korea. This study has experimented the physical performance of the natural ventilation in the heating period. The preheating function of the cold air by DFS can improve no doubt the performance of the natural ventilation at the cold season as well as spring and autumn. The physical difference between single and double facade on natural ventilation has been tested at the newly constructed laboratory, which can turn $360^{\circ}$ to confirm the characteristic of a facade with the various directions. The results show the natural ventilation of the DFS has definitely much more comfortable than that of the single facade system. The air velocity of the inflow as well as the air temperature in the DFS provide a more stable condition than in the SFS. The theoretical limit(air velocity max 0.2m/s, air temperature min. $18^{\circ}C$, temperature difference between 100mm and 1700mm height max. 3K) on the indoor comfortableness doesn't go over in the DFS. On the other hand, the SFS showed an unstable condition with an excess of comfortableness limit on air velocity as well as temperature. In view of the researching results so far achieved, the research came to a conclusion, that the DFS can provide a more comfortable indoor condition by the preheating in the heating period than a SFS, and the period of natural ventilation in winter time could be definitely increased at the DFS.

Comparison of Clinical Outcomes Using Various First-Aid Cooling Method for Burn (다양한 화상 응급처치의 치료효과 비교)

  • Lee, Jung Hwan;Song, Woo Jin;Kwon, Min Ju;Park, Yang Seo;Ko, Jang Hyu
    • Journal of the Korean Burn Society
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    • v.24 no.1
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    • pp.7-13
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    • 2021
  • Purpose: Currently, the most recommended method for burn first aid is the cool running water for 20 minutes (CRW20). If CRW20 is not practicable, cooling dressing products with tea tree oil are used as substitutes. In this study, we analyze the effect of various burn first aids, including CRW20, cooling products, on the treatment period. Methods: This study was conducted on patients who suffered burns and visited Hangangsoo Hospital from March 2019 to March 2020. The study conducted in a retrospective method. The duration of treatment was analyzed by dividing the experimental group. Results: The treatment period was shortened when first aid was given (P<0.001). Cold water, ice, and ice packs resulted in reduced treatment periods (P<0.001, P=0.004). The treatment period was reduced when cooling dressing products were used in all groups (P=0.041). The implementation of first aid has reduced the duration of burn treatment. This means that cooling helps burn treatment. CRW20 did not show statistically meaningful results. This is the result of a failure to fully control the temperature and time of tap water. In addition, the change in temperature of tap water according to season, the use of water is higher than that of animal testing, and the general lack of information on proper burn first aid may have affected. Conclusion: The treatment period was statistically significantly reduced in the group that performed first aid. Among the various first aid methods, cold water and ice reduced the treatment period.

Numerical Design of Light-off Auto-Catalyst for Reducing Cold-Start Emissions (냉간시동시 자동차용 저온활성촉매의 성능 향상을 위한 수치적 설계)

  • Jeong, Soo-Jin;Kim, Woo-Seung
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.24 no.9
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    • pp.1264-1276
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    • 2000
  • Light-off catalyst has been used for minimization of cold-start emissions. Improved cold-start performance of light-off catalyst needs the optimal design in terms of flow distribution, geometric surface area, precious metal loading, cell density and space velocity. In this study, these influential factors are numerically investigated using integrated numerical technique by considering not only 3-D fluid flow but also heat and mass transfer with chemical reactions. The present results indicate that uneven catalyst loading of depositing high active catalyst at upstream of monolith is beneficial during warm-up period but its effect is severely deteriorated when the space velocity is above 100,000 $hr^{-1}$ To maximize light-off performance, this study suggests that 1) a light-off catalyst be designed double substrate type; 2) the substrate with high GSA and high PM loading at face be placed at the front monolith; and 3) the cell density of the rear monolith be lower to reduce the pressure drop.