QT연장 증후군 환자에서 Head-Up Tilt Test에 의해 유발된 Torsades De Pointes 1례

전익수,차태준,김길수,김동완,김규종,김찬욱,김성만,주승재,이재우 대한순환기학회 2000 Korean Circulation Journal Vol.30 No.8

축산분뇨중의 암모니아성 질소 제거

진양오,최성우,김성우,김익성,신남철,박승조 동아대학교 환경문제연구소 1999 硏究報告 Vol.22 No.2

The purpose of thus study were to investigate the proper conditions of struvite formation in synthetic wastewater and then to apply these conditions to effluent of anaerobic digester of livestock wastewater The conditions of struvite formation had been studied by many researchers. But a little conditions were different among them. Especially, according to suspended solid variation in livestock wastewater was investigated by few researchers. In experiment of synthetic wastewater, the proper conditions of struvite formation were pH 105, l50rpm of mixing rate, 10 minutes of reaction time, and 20 minutes of precipitation time. At same time, the ammonia nitrogen removal rates were about 99.7%, 95.5%, and 96% of synthetic wastewater, raw wastewater, and effluent of anaerobic digester of livestock wastewater at molar ratio of 2(Mg):l(N)2(P) respectively. The larger factor of NH₄/SS constant was, the more effective the removal rate of ammonium nitrogen, SS was, but the less effective COD_(cr), and TOC was. By using XRD analysis, the most certain compound in precipitate of synthetic wastewater was struvite.

제주도 지하수 질산염 농도의 시·공간적 변화 특성: 장기(1993-2015) 모니터링 자료의 평가

김호림(Ho-Rim Kim),오준섭(Junseop Oh),도현권(Hyun-Kwon Do),이경진(Kyung-Jin Lee),현익현(Ik-Hyun Hyun),오상실(Sang-Sil Oh),감상규(Sang-Kyu Kam),윤성택(Seong-Taek Yun) 대한자원환경지질학회 2018 자원환경지질 Vol.51 No.1

1993년부터 2015년까지 관측된 제주도 지하수 장기모니터링 관측정(N = 4,835)에서 수집된 지하수 수질자료(N = 21,568)를 기반으로 질산성질소의 시공간적 변동 특성을 평가하였다. 제주도 지하수의 질산성질소 농도의 중앙값은 2.5 mg/L로서 다른 국가나 대륙의 조사 결과에 비해 다소 높거나 유사한 것으로 나타났다. 또한 지하수 용도, 행정구역 및 고도 별로 유의한 차이를 보였다. 특히, 산간 지역에 비해 저지대 해안가에 위치한 농업 및 주거지역에서 농도가 높음을 확인하였다. Mann-Kendall 및 Sen’s slope 분석을 활용한 질산성질소 농도의 추세 분석 결과, 하류 저지 대에 비해 중산간지역에서의 질산성질소 농도 증가 경향이 뚜렷하였다. 제주도 내 토지 피복의 시계열 변화 특성과 결부 지어 보면, 중산간지역의 오염 증가 추세는 농업지역의 확장 등 인위적 활동 증가에 기인한 결과로 판단된다. 반면,기지정된 지하수자원특별관리구역에서는 전반적으로 질산성질소 농도의 감소 경향이 나타났는데, 이는 지하수 관리 측면에서 수질관리를 위한 적극적인 정책이 유효함을 시사한다. 본 연구에서는 제주도 지하수의 질산성질소 오염관리를 위한 적정 방안을 제안한다. The spatio-temporal variations of nitrate concentrations in groundwater of Jeju Island were evaluated by an analysis of time series groundwater quality data (N = 21,568) that were collected from regional groundwater monitoring (number of wells = 4,835) for up to 20 years between 1993 and 2015. The median concentration of NO 3 -N is 2.5 mg/L, which is slightly higher than those reported from regional surveys in other countries. Nitrate concentrations of groundwater in wells tend to significantly vary according to different water usage (of the well), administrative districts, and topographic elevations: nitrate level is higher in low-lying agricultural and residential areas than those in high mountainous areas. The Mann-Kendall trend test and Sen’s slope analysis show that nitrate concentration in mid-mountainous areas tends to increase, possibly due to the expansion of agricultural areas toward highland. On the other hand, nitrate concentrations in the Specially Designated Groundwater Quality Protection Zones show the temporally decreasing trend, which implies the efficiency of groundwater management actions in Jeju. Proper measures for sustainable groundwater quality management are suggested in this study.

곡선형 강박스거더 도로교의 단면최적화에 관한 연구

김상효,조성범,정재익 연세대학교 산업기술연구소 1996 논문집 Vol.28 No.1

The steel-box girder decks are widely adopted for middle and long-span bridges due to many advantages, when comparing with other open-section girder types, such as higher torsional rigidity, better resistance against corrosion, etc. In current design practice, the design variables of steel-box girder are selected mainly on the basis of engineer's experience and direct observation. Then the assumed sections are checked for design limit states. Therefore, the resulted design sections are doubtful in the optimum viewpoint. To achieve more rational design, systematic design procedure is required, by which the design constraints on steel-box girders are satisfied and the design variables of minimum cost are obtained. Generally both bending moments by transverse loads and torsional moments by eccentric loadings are the most important load effects in curved steel-box girder bridges. Therefore, an optimization program is developed to consider the torsional moment in addition to other load effects. The efficiency of the developed program has been verified by redesigning some sections selected from existing bridge designs. The resulting optimum sections with discrete variables are found to be cost-saving and comparable with original sections. Based on the parametric studies performed for mainly radius of curvature on curved bridge and bridge width, some essential guidelines for rational design of curved steel-box girder bridges are suggested.

Co(Ⅲ)/Co(Ⅱ) 및 Fe(Ⅲ)/Fe(Ⅱ) 산화환원계에 의한 폴리에틸렌글리콜류의 매개전해산화

김익성,박정훈,박승조 동아대학교 환경문제연구소 2006 硏究報告 Vol.28 No.1

Mediated electrochemical oxidation (MEO) is an aqueous process which oxidizes organics electrochemically at low temperatures and ambient pressures. The process can be used to treat mixed wastes containing hazardous organics. This paper has studied MEO of polyethylene glycols (PEGs) in nitric acids by Fe/Fe(Ⅱ) and Co/Co(Ⅱ) system. It is investigated current density, supporting electrolyte concentration, hydraulic retention time, removal efficiency by PEGs continuous MEO. Removal efficiency of PEGs, electrical charge and reaction time by mediated electrochemical oxidation was excellent in Co/Co(Ⅱ) redox system than Fe/Fe(Ⅱ) redox system, indicating mediated electrochemical oxidation removal efficiency was 100 percent.

PCM 음성신호 복원 처리를 위한 RCV 필터 IC 설계

金東龍,趙成翊 全北大學校 1995 論文集 Vol.40 No.-

음성통신 시스템의 수신단에서 PCM(Pulse-Code-Modulation), 신호를 아날로그 음성신호로 변환하는 과정에서 고주파성분 (sin x)/x 성분 및 크기 왜곡 등이 발생되기 때문에 이 성분을 제거하여 보상하기 위한 RCV(Receive) 필터 회로가 필요하다. 본 논문에서는 AAF(Anti-Aliasing-Filter), SMF(Smoothing-Filter), RCV SCF(Switched-Capacitor-Filter)로 구성된 RCV 필터를 설계하는 방법을 제시하여 입력신호와 동일한 신호를 전송 받을 수 있게 하였다. 제안된 방법에 의하여 설계된 RCV 필터를 SPICE와 SCANAP를 이용하여 특성조사한 결과 설계조건과 일치함을 확인하였고, 집적화를 위해 MOSIS CMOS 2㎛ 설계규칙에 따라 레이아웃 하였다. The processing to transform the PCM(Pulse-Code-Modulation) signal into analog voice signal is accompanied with the high-frequency, the (sin x)/x and the amplitude distortion at the receive stage of voice signal telecommunication system. For this reason, there is necessity for Rcv(Receive) filter to compensating as being remove the components induced in the transform processing. In this paper, we proposed the design the design method of RCV filter block consisted of AAF(Anti-Aliasing-Filter, SMF(Smoothing), and RCV SCF(Switched-capacitor-Filter) to reconstruct the same signal as input signal. The designed RCV filter by the proposed method was in accord with specification in view of the results simulated on SPICE and SCANAP, and layouted by Mosis Cmos 2-um design rule for integrated circuits.

부산지역 일부 약수터에 대한 ‘맛있고 건강한 물’의 지표 적용

김현실,김익성,박청길,곽명화,윤철종,박승조 동아대학교 환경문제연구소 2001 硏究報告 Vol.24 No.2

This study was performed to investigate the water quality of some natural mineral springs in Busan. Samples for this study were collected at fifty sites during a year. from March 2000 to February 2001. The overall tendency of mineral was Na>Ca>Mg>K, and the seasonal variation of each components were like this - Ca: Win>Spr>Sum>Aut, Mg: Spr>Win>Sum>Aut, Na: Sum>Aut> Spr>Win, K: Aut>Sum>Spr>Win The K and O index suggested by Hashimoto was followed : delicious water(58%) > not belong to any group(34%) > healthy and delicious water(6%) > healthy water(2%).

Aerosol Reactor를 이용한 고분자 입자의 제조

김성익,김선근 중앙대학교 생산공학연구소 1992 생산공학연구소 논문집 Vol.1 No.1

Spherical polymer particles with narrow size distribution have been prepared by aerosol-phase polymerization. The aerosol-phase reactor has advantages over the conventional methods in the preparation of spherical, monodisperse particles with controllable size. The aerosol reaction system consisted of seed generator, boiler, condenser, reboiler, recondenser, reactor and particle collector in series. The polyurea particles were prepared by the reaction of TDI(toluene-2,4-diisocyanate) or HDI(hexamethylenediisocyanate) droplets with EDA(ethylenediamine) vapor. The use of seed(NaCl) nuclei helped the polymer particles smaller in size and made the size distribution of the particles narrower. The particle size increased substantially with boiler temperature and decrease slightly with increasing the carrier gas flow rate. Increase in reboiler temperature improved the monodispersity of the particle size. Sphericity and surface smoothness of the particles were improved by decreasing particle size and controlling the reaction rates. The coating of TiO₂on the surface of the preapared polymer paticles was carried out by condensing Ti(Oet)₄on the particle surface and subsequently reacting the liquid film with water vapor. The reaction system was also applied to prepare polyamide particles successfully.

셀룰라 오토마타 기반의 완전해싱

김한두,허성훈,문종익 인제대학교기초과학연구소 2002 자연과학 Vol.6 No.-

이 논문에서 셀룰라 오토마타를 이용한 완전해싱 방법을 제시하였다. In this paper we investigate the Cellular Automata-based perfect hashing scheme.

혼성왜곡방지를 위한 AAF 설계에 관한 연구

金東龍,趙成翊 全北大學校 1990 論文集 Vol.32 No.-

Because Filters do both the sampling or Sampled-and-Hold(S/H) operations, it result in the replication of the spectrum of input signal and (unless Nyquist's criterion is satisfied) induce aliasing distortion. In this paper, therefore, we designed AAF (Analog Anti-aliasing Filters) so as to remove high-frequency components from input signal for aliasing distortion prevention before input signal had been processed frequency selection by filters. and then, researched characteristics of it.