Experimental Study on the Spread Characteristics of Initial Fires According to Corridor Types

Kweon,Oh Sang,Kang,Hyun,Kim,Heung-Youl 한국방재학회 2021 한국방재학회논문집 Vol.21 No.4

건축물에서 화재 발생 시 복도는 화염과 연기의 확산 통로가 되어 재실자가 위험에 노출될 수 있다. 따라서 본 연구에서는 복도의 형태에 따른 화재의 특성을 분석하기 위해서 단방향 피난이 가능한 ‘L’ 형태와 양방향 피난이 가능한 ‘T’ 형태의 복도를 2.4(L) × 10(W) × 2 .4(H) m 크기로 제작하여 실물화재 실험을 진행하였다. 실물화재 실험은 2.0(W) × 1 .8(H) m 크기의 단일 개구부를 가지고 있는 2.4( L) × 3 .6(W) × 2 .4(H) m의 화재실에서 진행되었으며, 화재실 내부의 가연물은 ‘L’ 형태에서는 열방출률이 651.4 kW인 목재크립을 사용하고 ‘T’ 형태에서는 95.7 kW인 의자를 사용하였다. 실물화재 실험에서는 복도 내부의 온도 변화를 측정하였고 이른 통해 측정된 온도의 평균 최대값은 ‘L’ 형태에서 432.1 ℃로 ‘T’ 형태에서는 103.5 ℃로 나타났다. 또한, 실물화재 실험의 결과와 복도의 형태에 따른 환기특성을 BFD 곡선식에 적용하여 복도의 형태에 따른 화재성장 모델의 설계 과정을 제시하였다. During an accidental fire in buildings, the corridor becomes the path for flame and smoke to spread, exposing the occupants to danger. Therefore, this study conducted real-scale fire experiments using corridors of size 2.4(L) × 10(W) × 2.4(H) m an “L-type” corridor for one-way evacuation and a “T-type” corridor for two-way evacuation to analyze the characteristics of fire according to the shape of corridors. The real-scale fire experiments were conducted in a fire room (2.4(L) × 3.6(W) × 2.4(H) m) with a single opening (2.0(W) × 1.8(H) m). The combustibles used inside the fire room were wood cribs, with a heat release rate of 651.4 kW, in the L-type corridor and chairs, with a heat release rate of 95.7 kW, in the T-type corridor. The temperature inside the corridor was measured during the real-scale fire experiments, and the average maximum measured temperature was 432.1 °C in the L-type corridor and 103.5 °C in the T-type corridor. The experimental results and the ventilation characteristics according to the corridor types were applied to BFD curves to show the process of designing fire growth models according to corridor types.

복합시술 모발의 자외선 보호처리에 따른 손상도와 색상 변화

라채숙ㆍ권수애ㆍ이옥규(hae Suk LaㆍSoo Ae KweonㆍOk Kyu Lee) 한국인체미용예술학회 2016 한국인체미용예술학회지 Vol.17 No.1

This study aimed to determine the effects of UV-blocking by the type of UV care agent for complex-treated hair. For this, healthy women’s hair was permed, bleached and dyed, and a Polypeptide Protein Treatment and hair sunscreen agent were applied. After that, changes in the degree of wave formation, hair surface conditions, physical properties of the hair and hair hue were examined by irradiating UVB rays. The analysis results were found as follows: In terms of the degree of wave formation, no difference was observed among UV care agents. In terms of hair surface scale, hair damage was lower when the hair was coated twice as opposed to being coated once regardless of the type of the UV care agent and treatment method. In addition, tensile strength, elongation rate and resilience rate were superior in the hair recoated with the hair sunscreen agent. In contrast, no significant difference was observed among the UV care agents in terms of damage rates. Lightness and reflected light were also high in the hair recoated with the hair sunscreen agent. In addition, the a* value, reflection and dominant wavelength were the highest in the hair with post-treatment coating for the skin while b* value, reflection and degree of irritation was the highest in the hair with post-treatment coating for hair. The said results can be summarized as follows: The UV care agent revealed effective UV-blocking effects by maintaining the wave formation and preventing hair damage. When UV rays were irradiated, the hair for post-treatment product was the most efficient in maintaining hair color.

Difference of stage at cancer diagnosis by socioeconomic status for four target cancers of the National Cancer Screening Program in Korea: Results from the Gwangju and Jeonnam cancer registries

Kweon, Sun-Seog,Kim, Min-Gyeong,Kang, Mi-Ran,Shin, Min-Ho,Choi, Jin-Su Elsevier 2017 Journal of epidemiology Vol.27 No.7

<▼1><P><B>Background</B></P><P>The aim of this study was to evaluate whether stage at cancer diagnosis differed according to patient economic status.</P><P><B>Methods</B></P><P>A total of 10,528 patients with cancer of the stomach, colorectum, breast, or cervix, which are target organs of the Korean National Cancer Screening Program (NCSP; fully implemented in 2005) were extracted from population-based cancer registries. The patients were classified into four groups based on socioeconomic status (SES), as determined using their National Health Insurance (NHI) monthly premium at the time of cancer diagnosis. Cancer stage at diagnosis was defined as early (in situ/local) or late stage (regional/distant) based on the Surveillance, Epidemiology, and End Results (SEER) summary stage. Multivariable logistic regression analysis was performed to estimate the risk of non-local stage using age, residential area, and community deprivation index as covariates.</P><P><B>Results</B></P><P>The lowest SES subjects showed significantly higher risks of being diagnosed at a later stage for stomach, colorectal, and female breast cancer, but not for cervical cancer, compared with the highest SES subjects. The estimated ORs were 1.28 (95% CI, 1.10–1.49), 1.29 (95% CI, 1.03–1.61), and 1.35 (95% CI, 1.02–1.81) in the lowest SES subjects with stomach, colorectal, and breast cancer, respectively.</P><P><B>Conclusions</B></P><P>In conclusion, later stage diagnoses of stomach, colon, and female breast cancer are still associated with SES in Korea in the era of the NCSP for the lower SES population.</P></▼1><▼2><P><B>Highlights</B></P><P>•<P>Advanced stage was more frequent in cancer patients with lower economic status.</P>•<P>Differences of stage by SES were found in stomach, colorectal, and breast cancer.</P>•<P>Disparities still exist after the National Cancer Screening program in Korea.</P></P></▼2>

The Effect of Water Emulsified Fuel on a Motorway-Bus Diesel Engine

Kweonha Park,Inseok Kwak,Seungmook Oh 대한기계학회 2004 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.18 No.11

In this study, the combustion characteristics and durability of a diesel engine using emulsified fuel was investigated. Water was used in oil type emulsified fuel. In order to understand the effect of emulsified fuel in a wide range of engine running conditions, 0-13 mode was selected as a test condition, and a durability test was included to understand the long-term effect of water. Combustion pressure in a cylinder, exhaust emissions, specific fuel consumption, sound level and maximum torque were measured. NOx and PM were simultaneously reduced and the specific fuel consumption was increased and decreased at low and high loads, respectively. There was no trouble and any damage on the parts of the cylinder during a 500 hour durability test.<br/>

Relationship between Preharvest Factors and the Incidence of Storage Disorders in 'Fuji' Apples during CA Storage

Kweon, Hun-Joong,Kim, Mok-Jong,Moon, Yong-Sun,Lee, Jin-Wook,Choi, Cheol,Choi, Dong-Geun,Lee, Dong-Hoon,Kang, In-Kyu Korean Society of Horticultural Science 2012 원예과학기술지 Vol.30 No.1

This study was carried out to evaluate the effect of pre-harvest factors on fruit quality and the incidence of storage disorders in 'Fuji' apple during CA storage. Incidence of storage disorders varied, depending on the growing regions, field conditions, and altitude of the orchards. Results indicated that fruit maturity may play a crucial role in the incidence and severity of flesh browning and watercore. The incidence of these storage disorders increased with fruit maturity until 180 days after full bloom (DAFB). In addition, occurrence of watercore was correlated with the incidence of flesh browning during CA storage. The incidence of flesh browning was positively correlated with the sum of the diurnal temperature range from September through October and amount of precipitation from August to October in 1996-1999 growing years. These results suggested that 'Fuji' apple should be harvested no later than 180 DAFB because the late harvested fruits were prone to development of watercore which was correlated with the incidence of flesh browing during CA storage in Korea.

An Evaluation of Cockroach Allergies in Atopic Dermatitis

( Kweon Soo Kang ),( Chun Wook Park ),( Cheol Heon Lee ),( Hye Kyung Ahn ),( Dong Kyu Lee ) 대한피부과학회 2003 Annals of Dermatology Vol.15 No.2

N/A Background: Atopic dermatitis (AD) is primarily influenced by environmental factors including exposure to pollutants and indoor allergens (particularly, house dust mites). Although house dust mite antigens are the most prevalent components of indoor allergens in Korea, cockroaches also can be considered to act as an important allergen. Object: This study was done to evaluate the differences in three different atopic patch test(APT) techniques, and the relationship between APT and skin prick test, total IgE, and specific serum IgE level using cockroach allergen. Methods: We performed patch test in 57 patients with AD and 30 normal controls on clinically lesional and normal appearing skin with German cockroach (GC) allergens (extract, as is) in three different techniques (standard, scratch, DMSO). Reactions were evaluated after 48hours, and compared with the results of skin prick test, total and specific IgE levels. Detailed atopy history and severity scoring were taken. Results: In the GC (whole body) prick test positive group, there was 1263.02 IU/ml of total IgE, and this amount was significantly higher than GC (whole body) prick test negative group who had 549.46 IU/d (p<O.05). The positive reaction rate to whole body of American cockroach (AC) was significantly higher in the patient group than control group (p<O.05 ), but the positive rate to whole body of GC was high, but not significantly high in the patient group (p=0.053). There were significant differences in positive patch test reactions to either Ext or As is between patient group and control group (p<0.05 ). The positive rate to As is was significantly higher than to Ext in either lesional skin or non-lesional skin in patient group (p<0.05). But there were no considerable differences in positive reactions to either Ext or As is between 3 different methods (standard, scratch, DMSO mix) in both lesional and nan-lesional areas (p<0.05). There was no significant relationship between the positive reactions to patch test and prick test to Ext and As is antigen. The APT results showed no significant concordances with skin prick test and RAST for cockroach antigens. Conclusions: APT seems to be a different dimension of atopic skin inflammation and may provide further diagnostic information in addition to a patients history, skin prick test, and RAST results.

Detection of the Ultrasonic Signals due to Partial Discharges in a 154kV Transformer

Kweon, Dong-Jin,Chin, Sang-Bum,Kwak, Hee-Ro The Korean Institute of Electrical Engineers 2002 KIEE International Transactions on Electrophysics Vol.c2 No.6

We have developed an on-line ultrasonic detector to monitor partial discharge in an operating transformer. The ultrasonic sensor has 150[KHz] resonance frequency and contains a pre-amplifier with 60[㏈] gain. The on-line ultrasonic detector has 50~300[KHz] frequency band-pass filter to remove electrical and mechanical noises from the transformer. This detector has an ultrasonic signal discrimination algorithm which discriminates ultrasonic signals due to partial discharge in a transformer. A moving average method of ultrasonic signal number was employed to effectively monitor the increasing trend of the partial discharge. This paper describes an experience of partial discharge detection in a 154[㎸] operating transformer using an ultrasonic detector. With regards to gas analysis in oil, C2H2 gas was produced with a warning level in this transformer We detected ultrasonic signals on the transformer steel wall, and estimated the position of partial discharge. With further inspection, we found carbonized marks due to partial discharge on the supporting bolt which fastens the windings.

Male patients with rheumatoid arthritis have an increased risk of osteoporosis : Frequency and risk factors

Kweon, Seong-Min,Sohn, Dong Hyun,Park, Ji-Heh,Koh, Jung Hee,Park, Eun-Kyoung,Lee, Han-Na,Kim, Keunyoung,Kim, Yunkyung,Kim, Geun-Tae,Lee, Seung-Geun Wolters Kluwer Health 2018 Medicine Vol.97 No.24

<P><B>Abstract</B></P><P>Most previous research investigating osteoporosis in rheumatoid arthritis (RA) has focused on female patients and there is a lack of data regarding clinical characteristics of osteoporosis in male patients with RA.</P><P>The aim of this study was to compare the frequency of osteoporosis between male patients with RA and healthy patients, and to identify the risk factors for osteoporosis and low bone mineral density (BMD) in male patients with RA.</P><P>We conducted a retrospective, cross-sectional study including 76 South Korean male patients with RA aged over 50 years and 76 age-matched male healthy individuals. BMD was measured at the lumbar spine (L1-4) and left hip (femoral neck and total hip) using dual energy X-ray absorptiometry. Osteoporosis was defined as a <I>T</I>-score of ≤ −2.5 according to the World Health Organization (WHO) classification.</P><P>The frequency of osteoporosis at either the spine or the hip among male patients with RA was significantly higher than that among controls (22.4% vs 10.5%, <I>P</I> = .049) and RA patients had a significantly lower total hip BMD than healthy individuals (0.92 ± 0.14 vs 0.96 ± 0.1 g/cm<SUP>2</SUP>, <I>P</I> = .027). For male RA patients, the mean 28-joint Disease Activity Scores using erythrocyte sedimentation rate (DAS28-ESR) and body mass index (BMI) were 3.28 and 22 kg/m<SUP>2</SUP>, respectively. In multivariable logistic regression models, BMI ≤ 22 kg/m<SUP>2</SUP> (odds ratio = 3.43, <I>P</I> = .043) and DAS28-ESR > 3.2 (odds ratio = 3.85, <I>P</I> = .032) were independent risk factors for osteoporosis at either site in male patients with RA.</P><P>Our data demonstrate that male patients with RA had a 2.1 times higher risk for osteoporosis compared with healthy individuals. This suggests that appropriate management of osteoporosis in patients with RA is crucial not only for postmenopausal women but also for men aged over 50 years, especially those with low BMI and higher disease activity.</P>

Current status of red blood cell manufacturing in 3D culture and bioreactors

Kweon Soonho,Kim Suyeon,Baek Eun Jung 대한혈액학회 2023 Blood Research Vol.58 No.-

Owing to donor-related issues, blood shortages and transfusion-related adverse reactions have become global issues of grave concern. In vitro manufactured red blood cells (RBCs) are promising substitutes for blood donation. In the United Kingdom, a clinical trial for allogeneic mini transfusion of cultured RBCs derived from primary hematopoietic stem cells has recently begun. However, current production quantities are limited and need improved before clinical use. New methods to enhance manufacturing efficiencies have been explored, including different cell sources, bioreactors, and 3-dimensional (3D) materials; however, further research is required. In this review, we discuss various cell sources for blood cell production, recent advances in bioreactor manufacturing processes, and the clinical applications of cultured blood.

An Error Analysis for the Compressible Stokes Equations in a Strip with Inflow Boundary Condition

Kweon, Jae-Ryong KYUNGPOOK UNIVERSITY 1996 Kyungpook mathematical journal Vol.36 No.2

The pressure p in the continuity equation (1.1)_(b), using the initial condition, is solvable and expressed in terms of the integral of the divergence of the velocity u along the streamline. A finite element method for the resulted system is presented. The uniqueness of the solution (if it exists) of the discrete problem is shown and an optimal error analysis is given.