가속도계를 이용한 재료의 영계수 측정방법

손창호(Sohn, Chang-Ho),박진호(Park, Jin-Ho),윤두병(Yoon, Doo-Byung),정의필(Chong, Ui-Pil),최영철(Choi, Young-Chul) 한국소음진동공학회 2006 한국소음진동공학회 논문집 Vol.16 No.11

For the description of the elastic properties of linear objects a convenient parameter is the ratio of the stress to the strain, a parameter called the Young's modulus of the material. Young's modulus can be used to predict the elongation or compression of an object as long as the stress is less than the yield strength of the material. Conventional method for estimating Young's modulus measured the ratio of stress to corresponding strain below the proportional limit of a material using a tensile testing machine. But the method needs precision specimens and expensive equipment. In this paper, we proposed method for estimating Young's modulus using accelerometer. The basic idea comes from that the wave velocity is different as the Young's modulus. To obtain Young's modulus, a group velocity is obtained. It is difficult to measure group velocity. This is because plate medium has a dispersive characteristics which has different wave speed as frequency. In this paper, we used Wigner-Ville distribution to measure group velocity. To verify the proposed method, steel and acryl plate experiments have been performed. Experimental results show that the proposed method is powerful for estimating Young's modulus.

Projections of summertime ozone concentration over East Asia under multiple IPCC SRES emission scenarios

Lee, Jae-Bum,Cha, Jun-Seok,Hong, Sung-Chul,Choi, Jin-Young,Myoung, Ji-Su,Park, Rokjin J.,Woo, Jung-Hun,Ho, Changhoi,Han, Jin-Seok,Song, Chang-Keun Elsevier 2015 Atmospheric environment Vol.106 No.-

<P><B>Abstract</B></P> <P>We have developed the Integrated Climate and Air Quality Modeling System (ICAMS) through the one-way nesting of global–regional models to examine the changes in the surface ozone concentrations over East Asia under future climate scenarios. Model simulations have been conducted for the present period of 1996–2005 to evaluate the performance of ICAMS. The simulated surface ozone concentrations reproduced the observed monthly mean concentrations at sites in East Asia with high R<SUP>2</SUP> values (0.4–0.9), indicating a successful simulation to capture both spatial and temporal variability. We then performed several model simulations with the six IPCC SRES scenarios (A2, A1B, A1FI, A1T, B1, and B2) for the next three periods, 2016–2025 (the 2020s), 2046–2055 (the 2050s), and 2091–2100 (the 2090s). The model results show that the projected changes of the annual daily mean maximum eight-hour (DM8H) surface ozone concentrations in summertime for East Asia are in the range of 2–8 ppb, −3 to 8 ppb, and −7 to 9 ppb for the 2020s, the 2050s, and the 2090s, respectively, and are primarily determined based on the emission changes of NO<SUB>x</SUB> and NMVOC. The maximum increases in the annual DM8H surface ozone and high-ozone events occur in the 2020s for all scenarios except for A2, implying that the air quality over East Asia is likely to get worse in the near future period (the 2020s) than in the far future periods (the 2050s and the 2090s). The changes in the future environment based on IPCC SRES scenarios would also influence the change in the occurrences of high-concentrations events more greatly than that of the annual DM8H surface ozone concentrations. Sensitivity simulations show that the emissions increase is the key factor in determining future regional surface ozone concentrations in the case of a developing country, China, whereas a developed country, Japan would be influenced more greatly by effects of the regional climate change than the increase in emissions.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Change in ozone level is determined by the combination of NO<SUB>x</SUB> and NMVOC emissions. </LI> <LI> Ozone level over East Asia would get worse in the near future (the 2020s) than far future. </LI> <LI> A high-concentration event generally increases and more frequently occurs in the future. </LI> <LI> Change in ozone air quality in a developing country depends more on emissions change. </LI> <LI> Change in ozone air quality in a developed country depends more on climate change. </LI> </UL> </P>

Al³^(+) 존재가 ^(99m)Tc-MDP의 표지효율과 생체내 분포에 미치는 영향

장영수,정재민,김영주,곽철은,이동수,정준기,이명철,고창순 大韓核醫學會 1996 핵의학 분자영상 Vol.30 No.3

사염화탄소 투여 흰쥐에서 간섬유화 진행에 따른 Propranolol 의 약동학적 지표들의 변화

이민호,강주섭,강문수,윤병철,이오영,함준수,변재원,윤창옥 대한간학회 2001 Clinical and Molecular Hepatology(대한간학회지) Vol.7 No.2

Background/Aims : This study was designed to determine the effect of hepatic fibrotic severity on pharmacokinetics of propranolol in CC1q - treated rats. Methods - 1 mL/kg of 10% CC14 in olive oil was injected intramuscularly to rats twice weekly for 4, 6, 8 and 10 weeks, respectively (n=6). Control (n=6) was a sham - injected equal dose of olive oil for 10 weeks. After intravenous bolus injection of 2 mg/kg propranolol to rats, the serum propranolol concentrations were analyzed for 4 hours at various time points by a HPLC - fluorimetric system, and pharmacokinetic parameters such as Co, MRT, AUC, Vdss, tl/2(p) and CLp were determined. Then, a small amount of hepatic tissue was obtained and subjected to determination of the hepatic 4 - hydroxyproline content, which confirmed the hepatic fibrotic severity. Results : The serum concentrations of propranolol at 0.5, 1, 2 and 4 hours were significantly increased in CC1q-treated rats (p$lt;0.01). In proportion to the duration of CC4 treatment, Co and AUC were significantly increased, and Vdss and CLp were significantly decreased (p$lt;0.001). But MRT and t1/2(β) were not significantly changed. The hepatic 4 -hydroxyproline content was gradually increased in CC4-treated rats (p$lt;0.001). Conclusion - Gradual changes in pharmacokinetic parameters of propranolol were seen to be dependent on the hepatic fibrotic severity. We suggest that gradual dosage modification, according to their hepatic fibrotic severity, is necessary for many drugs administered to patients with chronic liver disease.(Korean J Hepatol 2001;7:181-188)

The Influence of Price and Customer Value on Long-term Purchasing of e-Commerce in Industrial Goods Market : Mediating Effects and Moderating Effects of Perceived Supplier Trust

Young-Chul Lee,Su-Ji Lim,Hoe-Chang Yang 한국유통과학회 2013 KODISA ICBE (International Conference on Business Vol.2013 No.-

In this study, B2B buyers bought according to theory of reasonable behavior(TRA) to select consumer values and price of personal goal of online shopping mall and social commerce and to investigate effects of factors upon long term purchasing as well as mediation and moderation effects of perceived supplier’s trust on website. The study investigated operation of TRA on online trade to find out conditions for optimum B2B e-trade. 235 copies of effective questionnaires who were industrial tool distribution of the B2B buying agent were collected. And we used regression, multiple regression and 3 step regression for verified hypotheses. Managerial or theoretical implications from this study as follows; First, B2B suppliers should give competitive prices to do long term online trade to give reasonable prices that buyers could accept. Second, mutual reaction of the trust was found to be effective between price and long-term purchasing only. As, suppliers who wanted to keep long term business relations by online commerce should have price competitiveness and take active actions against prices changes. Finally, TRA was found to be appropriate at B2B online commerce. So, further studies should be made to investigate behavioral factors of buyers of TRA as well as discovery of attitude factors of subjective norms and behaviors.

생쥐 위장관의 Interstitial cells of Cajal(ICC)에 대한 면역조직화학적 연구

김영철,차경훈,신무경,임건한,김주영,안병수,김장만,양경철,박도영,오재욱,장인엽 조선대학교 2003 The Medical Journal of Chosun University Vol.28 No.1

Background and Objectives : Interstitial cells of Cajal(ICC) are the pacemakers in gastrointestinal tract that modulates gastrointestinal motiliey and these cells also transmit neural input from enteric nerves to smooth muscles. Recent work on tissues from patients with motility disorders that suggest that loss or defect in ICC could be related to pathophysiology in human and animal models. Immunolabelling of ICC in intestinal wall is recently developed by using specific marker, anti-c-kit antibody. Immunohistochemistry was done for ICC network in attempt to provide a morphological basis for the mechanism regulating gastrointestinal motility Methods : Cryosection was done, and whole-mount preparations of mouse stomach, gastrointestinal tract were immunolabelled using the anti-c-Kit. Immunolabelled ICC networks were observed under a confocal laser scanning microscopy. Results : According to three dimensional reconstruction study, we found that the c-Kit-positive celluar networks were widely distributed in the gastrointestinal muscle (1) circular muscle layer(IC-IM), (2) myenteric plexus(IC-MY), (3) deep muscular plexus(IC-DMP) in ileum, (4) submucosal plexus(IC-SMP) and longitudinal muscle layer(IC-LM) in colon. Conclusion : The characteristic profiles of ICC celluar networks provide a morphological basis upon the mechanism regulating gastrointestinal motility. Additional studies for the enteric nerves-ICC interaction are need to evaluate the detailed roles of Icc in gastrointestinal tract.

고감도 Ames test(microsuspension assay)와 임파구 소핵시험법을 이용한 변이원성에 관한 조사 연구

안지영,김해준,윤인재,성영자,김영환,장영철 大韓産業醫學會 1996 대한직업환경의학회지 Vol.8 No.3

In order to evaluate the mutagenic effects of extractable indoor air pollutants (organic matters), we measured the mutagenic activities by sensitive microsuspension Ames test using new tester strains (YG 1024 and YG 1029). And additionally to evaluate the mutagenic effects on vital cell, we examined the frequencies of micronucleus appearing in lymphocytes from dye handling workers and controls. This study was conducted from Jan. to May, 1995. The extractable indoor air pollutants were collected by low volume air sampler in a general office room and 3 of dye handling factories. And the environment of general office room divided into 3 different groups according to the type of room heaters. To determine the frequencies of micronucleus appearing in lymphocytes, we sampled peripheral venous blood from 20 of dye handling workers and 20 of controls, and cultured, and then examined the lymphocytes. The results obtained were as follows: 1. The indirect mutagenic activities of extractable organic matters from suspended particulates collected in a general office room were higher than the direct one. 2. The strain YG 1024 was the most sensitive, and the increasing order of test strains that showed higher number of revertant were YG 1024, YG 1029, TA 100, TA 98. 3. In the general office room, the room using kerosene heater showed the highest mutagenecity, and the next was buthan gas heater, and non-heating room in order. 4. The mutagenic effects of suspended particulates in dye handling factories on the strain YG 1024 was 1.2 times higher than YG 1029. 5. The frequencies of micronucleus appearing in lymphocyte of the circulating blood of dye handling workers and the control were 5.65±2.97‰ and 4.65±0.97‰, respectively. And the difference was statistically significant.

척수손상후 운동 유발전위와 지각 유발전위의 비교

지철,이재수,하영수,최창락,송진언 대한신경외과학회 1987 Journal of Korean neurosurgical society Vol.16 No.4

Electrical monitoring of the nervous system offers the potential for the detection of injury, intraoperatively. The relationship of MEP(Motor Evoked Potential) and SEP(Sensory Evoked Potential) taken in 30 rats before and after spinal cord injury is reported. MEP was obtained from distal portion to the site of spinal cord injury by electrical stimulation of the cerebral motor cortex after insertion of a ball electrode in the cerebral motor cortex. SEP was collected at the cerebral somatosensory cortex during the sciatic nerve stimulation. Experimental animals were divided into a 20g㎝ spinal cord-trauma group and 50g㎝ spinal cord-trauma group. Changes of cardiopulmonary function after cerebral motor cortex stimulation and pre-and post-injury MEP and SEP were obtained at constant time interval. The results were follows : 1) Significant changes in blood pressure, pulse rate, and respiratory rate were noted to be elevated after stimulation of cerebral motor cortex and these were returned to normal in 10 minutes after stimulation. 2) MEP in control group showed that the latency was 8.6±1.54msec and the amplitude was 20.60±3.2㎶. In MEP of 20g㎝ spinal cord trauma group, the latency was increased to 30% (11.26±1.76msec) compared to control group at 10 minutes after the injury and the amplitude was decreased to 29% (14.60±2.99㎶). The latency was slowly decreased with the passage of time, to 21% increase. (10.42±1.84msec) at 1 hour after injury but the amplitude was not changed. In 50 g㎝ spinal cord-trauma group the latency was decreased to 75%(4.9±1.52㎶) compared to control group. With the passage of time, no change was revealed in latency but amplitude was decreased. The amplitude was decreased to 80%(4.00±1.49㎶) compared to control group. Change of MEP was marked in 50g㎝ spinal cord-trauma group. With the passage of time MEP was slightly improved in 20g㎝ spinal cord-trauma group but deteriorated in 50g㎝ spinal cord-trauma group. 3) The latency of SEP in control group was 12.22±0.7msec and the amplitude of those was 20.00±2.21㎶. No significant statistical change was recorded in the SEP of each spinal cord-trauma group compared to control group. MEP might be more important indicator than SEP in estimation and evaluation of the functional change of spinal cord injury.

장기간 수영훈련이 중년여성의 혈장 지질 및 아포단백질에 미치는 영향

김영준,장성동,어경철 동아대학교 스포츠과학연구소 2000 스포츠科學硏究論文集 Vol.18 No.-

The purpose of this study is to analyze the effects of long-term swimming excercise on thefat and aplipoprotein of middle-aged women. For the purpose, 14 middle-aged women who have no disease and do not any regular excercise are selected. They are divided into two groups. One is an exercise group(swimming group, Age : 39.0±2.12) consisting of seven members who are to make swimming exercise for eight weeks, and the other is a control group(control group, Age : 38.3±3.12). The effects of the exercise on fat and aplioprotein in blood are then examined. In terms of exercising method, the period, time and frequency of the swimming are determined as eight weeks, fifty minutes a day and five days a week respectively, The result of the study is as follows. 1.FFA, TG, TC and TC/HDL in blood plasma significantly decrease than before swimming, but LDL-C and HBL-C show no changes. 2.Aplipoprotein a and b in blood plasma show no changes over the eight weeks' exercise. Consequently, swimming exercise for eight weeks does not have an influence on LDL-C and HDL-C but on FFA, TG, TC and TC/HDL. The intensity, period and frequency of exercise should be maintained for change in cholesterol.

Free Paper Presentation : OS-53 ; Factors Associated with Smokers` will for Smoking Cessation in Korea

( Ah Young Leem ),( Chang Hoon Han ),( Chul Min Ahn ),( Tae Hoon Jung ),( Yu Il Kim ),( Jae Yeol Kim ),( Sang Haak Lee ),( Eun Mi Chun ),( Kwang Ha Yoo ),( Ji Ye Jung ) 대한결핵 및 호흡기학회 2014 대한결핵 및 호흡기학회 추계학술대회 초록집 Vol.118 No.-

Background: Smoking is known to increase the risk of chronic disease. Understanding of factors that contribute to smoking cessation may help to develop strategies for smoking behavior change. Methods: Pooled cross-sectional data of 11,924 subjects from the Korea National Health and Nutrition Examination Survey II-V were analyzed. The stages of change in smoking cessation were categorized into pre-contemplation, contemplation, and preparation. Baseline characteristics, socioeconomic factors, quality of life, psychological characteristics, and tobacco-related factors were compared between the groups. Results: The study population consisted of 32.4% in pre-contemplation, 54.4% in contemplation, and 13.1% in preparation group. While the proportion for pre-contemplation group (37.4% to 28.4%) tended to decrease from 2001 to 2012, that of preparation group (6.4% to 18.1%) tended to increase. The mean age of pre-contemplation group (48.4±16.2) is higher than comtemplation and preparation group (42.2±13.9 and 44.4±15.3; P=0.02). As levels of education and income status increased, the proportion of pre-contemplation tended to decrease, and that of preparation tended to increase. Proportion of blue collar job in pre-contemplation group was higher than in preparation group (67.9% vs 58.1%; P<0.001). In pre-contemplation group, percentage of suicidal ideation within 1 year was higher than contemplation and preparation group (19.3% vs 16.0% and 16.1%). Upon adjusting analysis, the proportion of pre-contemplation group increased with increasing age (OR=1.01; 95%CI 1.01-1.02), and smoking amount (OR=1.04; 95%CI 1.03-1.05). People of pre-contemplation group (vs. preparation) are be less educated (OR=1.99; 95% CI 1.51-2.62), are in single marital status (OR=1.25; 95%CI 1.04-1.50), have lower prevalence of cardiovascular disease (OR=0.48; 95%CI 0.31-0.76), and do less exercise walking (OR=1.36; 95%CI 1.09-1.69) and weight training (OR=1.59; 95%CI 1.35-1.85). Conclusions: We demonstrated a significant association between the stages of change in smoking cessation and age, education, marital status, cardiovascular disease, and amount of exercise.