Cover Story - 폭염: 여름철 폭염 현황 및 대책

하종식,Ha, Jong-Sik 한국방재협회 2012 방재저널 Vol.14 No.5

PM10과 오존이 연령군별 천식 입원에 미치는 영향

배현주,하종식,이애경,박정임,Bae, Hyun-Joo,Ha, Jong-Sik,Lee, Ae-Kyung,Park, Jeong-Im 한국환경보건학회 2008 한국환경보건학회지 Vol.34 No.2

This study investigated the age dependencies in ambient air pollution-associated asthma hospitalization from 2003 to 2005 in Seoul. For all ages and the age groups of 0-14, 15-64, and 65+years, the Generalized Additive Model (GAM) was used to estimate the relative risks of daily asthma hospitalization associated with changes in particulate matter and ozone. The time-trends, seasonal variances, day effects, temperature, humidity, and pressure at sea level were controlled in the models. Significant associations were observed between asthma hospitalization and the levels of $PM_{10}$ and $O_3$. The relative risks (RRs) of asthma hospitalization for every 10 unit increases in $PM_{10}({\mu}g/m^3)$ and $O_3$(ppb) were 1.008 (95% CI 1.005-1.012), and 1.012 (95% CI 1.003-1.020), respectively. Evaluated over $10\;{\mu}g/m^3$ increase in $PM_{10}$, we found the relative risks of asthma hospitalization to be 1.009 (95% CI 1.004-1.014) in 0-14 age group, and 1.015 (95% CI 1.008-1.022) in 65+ age group. Considering 10 ppb increase in $O_3$, those were 1.014 (95% CI 1.003-1.024) in 0-14 age group, and 1.025 (95% CI 1.009-1.041) in 65+ age group. It was concluded that current levels of ambient air pollution in Seoul make a significant contribution to the variation in daily asthma hospitalization. Further reduction in air pollution is necessary to protect the health of the community, especially that of the higher risky groups including children and elderly population.

2004년도 경기도 보건소 결핵환자로부터 분리된 결핵균 DNA 지문분석

박영길 ( Young Kil Park ),강희윤 ( Hee Yeun Kang ),임장근 ( Jang Geun Lim ),하종식 ( Jong Sik Ha ),조정옥 ( Jung Ok Cho ),최향순 ( Hang Soon Choi ),이계철 ( Ka Chel Lee ),최영화 ( Young Hwa Choi ),신승수 ( Seung Soo Sheen ),전기홍 대한결핵 및 호흡기학회 2006 Tuberculosis and Respiratory Diseases Vol.60 No.3

공공하수처리장의 에너지 소비현황 및 효율성 평가

조을생 ( Eul Saeng Cho ),한대호 ( Dae Ho Han ),하종식 ( Jong Sik Ha ) 한국환경정책평가연구원 2012 환경정책연구 Vol.11 No.4

국내 공공하수처리시설의 운영적 측면의 에너지 절감을 위한 방안을 모색하기 위해 에너지 효율성을 평가하였다. 하수처리시설의 에너지 사용에 영향을 미치는 변수를 통계적(유의수준 5%)으로 분석한 결과 유입하수량, 유입 COD, 유입 BOD, 고도처리비율, 유입 TN, 유입 TP, 실제 처리용량/설계용량 비율(가동률)로 나타나 국내 하수처리시설의 에너지 사용은 주로 하수 유입수의 성상 및 하수처리시설 가동률에 영향을 받는 것으로 분석되었다. 또한 회귀분석 결과, 에너지 효율성이 평균(50 백분위수) 이상인 하수처리장 비율을 공법별로 살펴보면, A2O 공법을 적용하고 있는 하수처리시설이 상대적으로 에너지 효율성이 높게 운영된 것으로 평가되었으며 반면에 고도처리 공법에서는 분리막고도처리, 2차 처리공법에서는 접촉산화법을 적용하고 있는 하수처리시설의 에너지 효율성 개선 노력이 상대적으로 더 많이 요구되는 것으로 나타났다. 그러나 보다 정확한 하수처리시설의 에너지 소비산정 및 분석을 위해서는 처리시설의 에너지 사용 모니터링 시스템 구축 및 에너지 소비시설의 정확한 DB 구축이 시급한 실정이다. 특히, 기존 하수도통계자료에 i) 중계펌프 사용 전력량, ii) 단위공정별 전력량, iii) 처리수 장거리 방류시 펌프 전력사용량, iv) 대체에너지 생산량 및 활용현황 등에 대한 정확한 자료가 보완되어야 한다. 기초자료가 제대로 구축될 경우 유사한 하수처리시설의 에너지 소비 형태에 대해 구체적으로 비교·분석이 가능하며 분석결과를 활용하여 벤치마킹을 통한 각 하수처리장들의 특성에 따른 맞춤형 에너지 절감 방안이 수립될 수 있을 것이다. In this paper, the energy efficiency of wastewater utilities was evaluated to explore ways to save energy via operational measures. The correlation of each wastewater characteristic parameter to energy was assessed to find a set of parameters that explained most of the variations in energy use among utilities. The results show that increases in inflow, influent COD concentration, and ratio of advanced treatment generally increased the energy use. On the other hand, increases in load factor (influent average flow/design flow) reduced the energy use. In the regression analysis, the energy efficiency was highest in the A2O advanced process. On the other hand, the membrane process (among the advanced processes) and the contacted aeration process (among the secondary processes) require more efforts in saving energy. However, the data base system related to energy use must be supplemented in order for more accurate analysis of energy consumption in wastewater treatment facilities. In particular, i) electricity consumption of relay pumps and, ii) energy usage per unit process, iii) pump power usage to discharge treated wastewater in a long distance, if necessary, and iv) alternative energy production and utilization status must be recorded. By utilizing the results of the analysis conducted in this study, it is possible to quantify a level of energy savings needed and establish customized energy saving measures to achieve a certain target level for benchmarking a successful case of wastewater utilities.

A Study on Analysis of Dynamic Characteristics and Evaluation of Dynamic Compliance of a 5 Axis Multi-tasking Machine Tool by Using F.E.M and Exciter Test

Sung-Hyun Jang(장성현),Young-Hyu Choi(최영휴),Jong-Sik Ha(하종식) 한국생산제조학회 2009 한국생산제조학회지 Vol.18 No.2

This paper describes a study on dynamic characteristics analysis and dynamic compliance evaluation of a 5-axis multi-tasking machine tool of ram-head type. Structural dynamics analysis and evaluation are necessary to machine tool design and development to secure good machine tool performance against tough and harsh machining conditions. In this study, natural frequencies and corresponding vibration modes of the machine tool structure were analyzed by using both F.E.M. modal analysis and impulse hammer test. Furthermore, dynamic compliance of the machine tool was analyzed by using F.E.M. and also measured by using a hydraulic exciter test. Both the theoretical analysis and experimental test results showed good agreement with each other.

라우터머신용 랙 피니언 방식 이송시스템의 / 진동해석 및 동적설계 최적화

최영휴(Young-Hyu Choi),최응영(Eung-Young Choi),장성현(Sung-Hyun Jang),하종식(Jong-Sik Ha),조용주(Yong-Ju Cho) 대한기계학회 2005 대한기계학회 춘추학술대회 Vol.2005 No.5

In order to prevent a router machine feed drive system from transient operational vibration, this paper presents vibration analysis and dynamic design optimization of a rack and pinion typed feed drive system for a router machine. The feed drive system was mathematically idealized as a 5-degree-of-freedom lumped parameter model. Stiffness parameters of motor-shaft, rack and pinion gears, and machine structure were appropriately considered in the modeling. Computational experiment was carried out to obtain vibrations of the feed drive system during its transient speed operation. Furthermore, optimum design parameters were successfully obtained by using a Genetic Algorithm based design optimization method.

5-Head Router Machine 구조물의 진동최소화를 위한 동적설계 최적화

최영휴(Young-Hyu Choi),장성현(Sung-Hyun Jang),최응영(Eung-Young Choi),하종식(Jong-Sik Ha),조용주(Yong-Ju Cho) 대한기계학회 2005 대한기계학회 춘추학술대회 Vol.2005 No.5

This paper presents a multi-step design optimization for 5-head router machine using a genetic algorithm. The design problem is to find out the optimum configuration and thickness of structural members which minimize vibrations, the static compliance, dynamic compliance and weights of the machine structure simultaneously under several constraints such as dimensional constraints, maximum deflection limit, safety criterion and maximum vibration amplitude limit. Optimization results showed a great reduction in compliance and vibration amplitude at the spindle nose of the router machine without increase of machine weight.

내독소로 유도되는 Nuclear Factor Kappa B 활성화에 미치는 Src Family Kinase의 조절기전

김희재,이혜원,이희수,하종식,이지희 이화여자대학교 의과대학 2003 EMJ (Ewha medical journal) Vol.26 No.2

목적: Src family tyrosine kinases (TK)가 내독소로 인해 유도되는 NF-kB 활성화 신호전달체계에 연관되어 있음이 보고된 바 있다. 또한 내독소(LPS)나 TNF a와 같은 여러 자극제는 IkB-a 의 serine기 또는 tyrosine기의 인산화를 통하여 NF-kB를 활성화 시킨다고 알려진 바 있다. 이에 본 연구에서는 RAW 264.7 대식세포에 내독소 투여 시 유도되는 NF-kB활성화 및 NF-kB 의존성 염증성인자 생성에 대한 Src TK의 역할에 대해 규명하고자 한다. 방법: American Type Culture Collection 에서 구입한 생쥐의 대식세포, RAW264.를 내독소(LPS)에 노출시킨 후 damnacanthal나 PP1을 처리하여, EMSA, Nitrite assay, Western blot을 통하여Src TK가 NF-kB활성과 염증인자의 생성에 있어서 어떤 역할을 하는지에 대하여 조사하였고 내독소 투여로 인한 NF-kB활성에 있어서 Src TK의 기본적인 작용기전에 대해 조사하였다. 결과: Damnacanthal이나 PP1은 Src TK 특이적 억제제로 알려져 있는데, 본 연구에서는 Src TK의 특이적 억제제인 damnacanthal 이나 PP1을 사용하였고, RAW 264.7 대식세포에서 Src TK 특이 억제제의 전처치는 내독소로 유도되는 NF-kB활성을 차단시켰다. 또한 내독소 투여로 증가된 NO 생성은 damnacanthal이나 PP1에 의하여 억제되었다. 이런 TK kinase 억제제는 내독소로 유도되는 serine 기 인산화와 IkB-a 분해를 억제시켰다. 결론: Src kinase 특이적 억제제인 damnacanthal 그리고 PP1이 RAW 264.7세포에서 내독소로 유도되는 NF-kB활성과 Nitric Oxide 생성을 차단시켰다. 또한. Damna-canthal이나 PP1은 내독소로 유도된 serine기 인산화와 IkB-a의 분해를 억제시켰다. Objectives : Src family tyrosine kinases(TK) have been found to be involved in LPS induc-tion of signal cascades. Furthermore Lipopolysaccharide(LPS) or Tumor necrosis factor alpha (TNF-a) activate nuclear transcription factor kB(NF-kB) by inducing serine or tyrosine pho-sphorylation of the inhibitory subunit of NF-k B(I k B- a). In this study, it is our purpose to search the role of Src TK in LPS induced activation of NF-k B and NF-k B dependent induced inflam-matory factors. Methods : Nuclear extracts were prepared from RAW 264.7 cells pretreated with damnacan-thal or PP1 and then stimulate with LPS. After that, we figured out the dffects of inhibition of Src family kinases on LPS-induced activation of NF-kB by EMSA. We investigated effects of damnacanthal of PP1 on the production of NO by Griess assay and LPS-induced serine phos-phorylation and degradation of Ik B-a by Western blots in LPS-stimulated RAW263.7 cells. Results : Inhibition of Src TK with damnacanthal or PP1 blocked LPS-induced NF-kB acti-vation at the range of nanomolar concentrations. Substantial inhibition in LPS-induced production of NO was also observed in cells treated with damnacanthal or PP1. These kinase inhibitors blocked LPS-induced the serine phosphorylation, and the degradation of Ik B-a. Conclusion : we investigated the role of Src TK in NF-k B activation and production of nitric oxide (NO) in LPS stimulated RAW 264.7 macrophages and the underlying mechanism by which Src TK play a role in LPS-induction of the possible pathways leading to NF-k B activation. Src kinase specific inhibitors, damnacanthal and PP1 blocked LPS induced activating NF-k B and producing Nitric Oxide in Raw 264.7 machrophages. Moreover, Damnacanthal and PP1 inhibited LPS induced serine phosphorylation and degradation of Ik B-a.

다기능 5축 복합가공기 구조 최적설계 및 동강성 평가

정용민,장성현,황현영,최영휴,하종식 한국공작기계학회 2008 한국공작기계학회 추계학술대회논문집 Vol.2008 No.-

This paper describes a structural design. optimization for light weight and minimum compliance using G.A. and a study on dynamic stiffness evaluation of a 5-axes multi-tasking machine tool. Dynamic stiffness is one of important factors regarding to machine tool accuracy. In design optimization, we optimized the thickness of structural member which minimize the compliance and weight of the machine structure under several constraints. Furthermore, dynamic stiffness, in this study, were obtained by using both FEM analysis and an experimental dynamic stiffness test, that is a random excitation test by using a hydraulic exciter. Both the theoretical and experiment analysis results showed good agreement with each other. Finally, some discussion and review from the view point absolute dynamic stiffness were made based on the analysis results.

토끼 음경 해면체 평활근에서 Atropine의 약리작용과 기전

최영득,정우식,하종식,권성원 이화여자대학교 생명과학연구소 1995 생명과학연구논문집 Vol.6 No.-

Atropine is the classic antimuscarinic anticholinergic grug that has been used to block cholinergic neurotransmission in basic research and received recent interest clinically in the intracavemous pharmacotherapy of erectile dysfunction. It has been suggested that at low dose(10^-8M), atropine blocks muscarinic receptors, thereby reducing both cholinergic of the adrenergic and cholinergic excitation of the NANC neuroeffector systems, on the other hand, at large pharmacologic dose(10^-3M), induces the release of EDRF which recently has been identified as nitric oxide(NO) of NO like substance. Therefore, we tried to confirm the action of atropine in the cavernosal tissue and define its mechanism. Strips of rabbit corpus cavernosum were isolated and mounted in 10ml organ chambers to measure isometric tension. Muscle strips submaximally precontracted with phenylephrine(5×10^-6M) and treated with increasing concentrations of atropine(10^-11M to 10^-3M) showed tension increase upto 10^-8M of atropine, and thereafter, relaxed concentration-dependently(10^-7: 43.7%, 10^-6M: 63.0%, 10^-5M: 86.2%, 10^-4M: 93.6%, 10^-3M: 100%). Relaxations to atropine(5×10^-6M) were not inhibited even partially by endothelial disruption or by pretreatment with methylene blue or pyrogallol. Pretreatment of muscle strips with atropine(5×10^-6M) caused concentration-related inhibition of a phenylephrine induced contraction, and in calcium-free high potassium depolarizing solution, decreased basal tension as well as inhibited contraction induced by CaCl_2. However, atropine did not produce reduction of responses to depolarizing medium(20, 40, 80mM KCl). With these results we can confirm the relaxation effect of atropine at a larger dose(>10^-7M) on the cavernosal smooth muscle and suggest that its action is mediated by increasing intracellular calcium sequestration, not by hyperpolarization or EDRF.