Histamine이 개의 자궁 평활근 운동성에 미치는 영향

鄭憲植,金鍾涉,金周憲 慶尙大學校 1985 論文集 Vol.24 No.1

The responses of motility to histamine were investigated with canine uterine longitudinal muscle. The results were summarized as follows: 1. Histamine has been shown to induce contractility with dose-dependent between 10_-7 M and 10_-5 M in canine uterine longitudinal muscle. 2. The contraction induced by histamine was completely blocked by Hi-receptor blocker, chlorpheniramine, at a concentration of 10_-6 M; but was not blocked by H_2-receptor blocker, cimetidine, at a concentration of 5×10_-7 M. 3. The contraction induced by histamine was not blocked by the cholinergic receptor blocker, atropine, at a concentration of 10_-6M. 4. The contraction induced by histamine did not affect adrenergic o-receptor blocker, phenoxybenzamine(10_-6M), and adrenergic β-receptor blocker, propranolol(10_-6M). From these results, it was concluded in dog that the contractility of uterine smooth muscle by histamine was only through H_1-receptor, and that it may not be related to the cholinergic and adrenergic receptor.

동기적 검사점 기법에서의 쓰레기 처리 기법

정광식,안병주,유헌창,황종선 고려대학교 컴퓨터과학기술연구소 2001 JOURNAL OF COMPUTER SCIENCE & ENGINEERING TECHNOLO Vol.3 No.-

이 논문은 동기적 검사점 기법에서 결함 포용을 목적으로 불안전 저장 장치(volatile storage)에 저장되는 메시지 로그과 안전 저장 장치에 저장되는 검사점의 쓰레기 처리 기법을 제안한다. 기존의 동기적 검사점 기법을 기반으로 한 결함 정보 쓰레기 처리 기법은 가장 최근의 검사점을 제외한 모든 결함 정보를 쓰레기 처리하였다. 하지만 TCP/IP와 같은 신뢰성을 갖는 동기적 검사점 기법이 가장 최근의 검사점만을 복귀 회복 기법에서 사용한다면, 불필요한 복귀(sympathetic rollback)가 발생된다. 이 논문은 동기적 검사점 기법에서 손실 메시지(lost message)를 해결하기 위해 각 프로세스가 동기화된 가장 최근의 검사점외에 검사점이나 메시지 로그를 유지해야 한다는 것을 입증했다. 또한 손실 메시지 해결을 위해 관리되어야 하는 검사점이나 메시지 로그가 쓰레기 처리되어지기 위해 필요한 조건을 새롭게 정의하며, 이 정의를 기반으로 한 검사점과 메시지 로그의 쓰레기 처리 알고리즘을 제안한다. 제시된 조건을 기반으로 한 검사점과 메시지 로그의 쓰레기 처리는 송수신 메시지에 부가된 손실 메시지 관련 프로세스 정보를 이용하므로 쓰레기 처리를 위한 부가적인 메시지를 발생시키지 않는다. 제안된 기법은 일반 메시지가 송수신되기 전까지 쓰레기 처리가 지연되는 '지연 쓰레기 처리 현상(lazy garbage collection)'을 발생시킨다. 하지만 '지연 쓰레기 처리 현상'은 분산 시스템의 일관성을 위배하지 않는다. This paper presents a garbage collection protocol for checkpoints and message logs which are saved on the stable storage or volatile storage for fault tolerancy. The previous works of garbage collections in coordinated checkpointing protocol delete all the checkpoints except for the last checkpoints on each processes. But implemented on top of reliable communication protocol like as TCP/IP, rollback recovery protocol based on only last checkpoints makes sympathetic rollback. We show that the old checkpoints or message logs except for the last checkpoints have to be preserved in order to replay the lost messages. And we define the conditions for garbage collection of checkpoints and message logs for lost messages and present the garbage collection algorithm for checkpoints and message logs in coordinated checkpointing protocol. Since the proposed algorithm uses process information for lost message piggybacked with messages, the additional messages for garbage collection is not needed. The proposed garbage collection algorithm makes 'the lazy garbage collection effect', because relying on the piggybacked checkpoint information in send/receive message. But 'the lazy garbage collection effect' does not break the consistency of the whole systems.

티타늄의 THP공정 중 수소화 과정 수치해석

정순효,하헌필,변지영 대한금속재료학회 2004 대한금속·재료학회지 Vol.42 No.5

A fixed grid, finite volume model was applied to investigate hydrogen absorption, diffusion and moving boundary α/βphase transformation that occurs during hydrogenation and homogenization annealing of cylindrical titanium specimens. Effects of parameters such as temperature, specimen radius, amount of added hydrogen on the times required for hydrogenation, for completion of α/βphase transformation and for homogenization were studied. It was found that hydrogen absorption rate is mostly influenced by surface reaction rather than solid-state diffusion. Time for hydrogenation becomes somewhat shorter with increase of temperature, due to decrease of hydrogen saturation concentration in spite of large increase of diffusivity and reaction rate constant. It increases almost linearly with increasing specimen radius or with amount of hydrogenation, showing positive deviation from linearity due to increase of diffusion resistance or surface hydrogen concentration. The completion of α/βphase transformation and homogenization are finished quickly with raising temperature due to increase of diffusivity and decrease of equilibrium hydrogen concentration in the βphase. They are nearly proportional to the square of specimen radius. With increase of the amount of added hydrogen, the completion of α/β phase transformation and homogenization are finished quickly during annealing due to the progress of α/β phase transformation during hydrogenation (Received August 23, 2003)

高强度 鐵筋콘크리트 보의 전단강도에 관한 實驗的 硏究(Ⅰ)

정헌수,박기철 중앙대학교 기술과학연구소 1989 기술과학연구소 논문집 Vol.19 No.-

A total of 45 beams was Tested in identical size rectangular beams (12×20cm). This experimental investigation was conducted to determine the diagonal cracking and ultimate shear strength. The major variables are: a) concrete compression strength b) web reinforcement (rfvy) c) Shear Span ratio (a/d)

프랑스法上의 營業質制度에 관한 考察

鄭容相,河憲註 부산 외국어 대학교 2004 外大論叢 Vol.28 No.-

Avant ces re´formes, le fonds de commerce ne pouvait e^tre donne´ en gage que conforme´ment au droit commun, c'est-a`-dire par la de´possession. C'e´tait rendre impraticable le gage, le comme¸cant ne pouvant accepter de se de´posse´der de son fonds. Le nantissement porte de plein droit sur les principaux e´le´ments incorporels du fonds: cliente`le, enseigne et nom commercial, droit au bail. Il peut en outre porter, si 1'acte le stipule express´ement, sur les droits de proprie´te´ industrielle et le mate´riel, a` condition toutefois pour ce dernier que le proprie´taire du fonds ne soit pas en me^me temps proprie´taire des locaux. Comme un cre´ancier hypothe´caire, le cre´ancier nanti n'a pas la possession du fonds que conserve le de´biteur avec le droit d'alie´ner. Mais 1'aricle 22 de la loi de 1909 le dote d'un droit de suite, lui permettant donc de faire vendre le fonds passe´ entre les mains d'un tiers acque´reur. Non rembourse´, le cre´ancier nantipeut faire ordonner la vente du fonds huit jours apre`s sommation de payer faite au de´biteur et au tiers de´tenteur, s'ilya lieu, demeure´e infructueuse.

티타늄의 THP공정에서의 수소제거 과정 수치해석

정순효,하헌필,변지영 대한금속재료학회 2004 대한금속·재료학회지 Vol.42 No.8

A previously developed fixed grid finite volume method was used to investigate hydrogen removal process involving surface reaction, diffusion, β/α phase boundary movement and phase transformation that occurs during dehydrogenation of cylindrical β-titanium specimens. Effects of temperature, initial hydrogen content and radius of specimen on times for dehydrogenation were studied. It was found that dehydrogenaion occus through the following 4 steps: (1) lowering of hydrogen concentration at the surface of the β specimen to equilibrium value, (2) lowering of hydrogen concentration gradient to a value matching the surface reaction flux. (3) the (β/α phase transformation by inward movement of the β/α phase boundary and (4) further removal of hydrogen in the a phase specimen to final value. Time for hydrogen removal in the first step increases with increase of temperature and initial hydrogen content, due to the rapid increase of amount of hydrogen to be removed comparing with the increase of hydrogen removal rate. It increases with specimen radius. Time for hydrogen removal in 2nd step decreases with increase of temperature due to increase of hydrogen removal rate and decrease of amount of hydrogen to be removed, but it increases with specimen radius and initial hydrogen content. Time for hydrogen removal in 3rd step (β/α phase transformation) decreases with increase of temperature due to decrease of diffusion and reaction resistance and due to increase of partition coefficient, but it increases with specimen radius due to increase of diffusion and reaction resistance. It increases with initial hydrogen content. Time for hydrogen removal in 4th step decreases with increase of temperature due to decrease of diffusion and reaction resistance as well as equilibrium concentration, but it increases with specimen radius due to increase of diffusion and reaction resistance.

일방향 합성슬래브의 사용성 확보를 위한 유효단면 2차 모멘트 및 경간 깊이비 평가

정헌수 중앙대학교 기술과학연구소 2003 기술과학연구소 논문집 Vol.33 No.-

인장균열효과와 인장강성효과를 수반한 유효단면 2차모멘트의 적절한 평가는 구조용 테크플레이트를 사용한 일방향 합성슬래브 설계에서 중요하게 고려되는 사항이다 특히 고강도 구조용 데크플레이트와 않은 단면의 일반적인 사용으로 일방향 슬래브의 사용성 확보가 더 중요하게 된 원인이 되었다. 유효단면 2차 모멘트의 산정방법과 일방향 슬래브에서 처짐 제어를 위한 허용 경간깊이비가 제시되었다. 새롭게 제시된 유효 단면2차모멘트 평가식은 균열 단면2차모멘트의 계산과정을 생략함으로써 간단하게 적용할 수 있다. 장기처짐 제한을 위한 허용 경간깊이비는 하중조건, 지지조건, 데크플레이트비, 스팬길이와 ACI 318-02에 의한 허용처짐을 고려하고 있다. 본 연구에서 제시된 방법은 ACI 318-02 또는 ANSI/ASCE와 같은 설계기준보다 더 적절하다고 판단된다. A proper evaluation of effective moment of inertia involved tensile cracking effect and tension stiffening effect is an important consideration in the design of one-way composite slabs reinforced with wtructural steel decking. Especially common uses of high-strength reinforcing structural steel decking and shallow sections caused serviceability of one-way composite slabs to be of more importance. Methods to evaluate effective moment of inertia and allowable span-depth ratio for controlling deflection in one-way composite slabs were developed. A new presented formula for effective moment of inertia can apply to be simple as eliminating the necessity of computing moment of inertia of cracked section. Allowable span-depth ratio that limitation of long-term deflections will be satisfactory considered loading conditions, support conditions, deck plate ratio, span length, and allowable deflections in ACI 318-02. The proposed methods in this study show a more justifiable than other procedures such as ACI 318-02 and ANSI/ASCE.

구조용 데크플레이트를 사용한 연속 합성슬래브 시스템의 모멘트 재분배 및 소성회전능력

정헌수,은희창,양근혁 대한건축학회 2005 大韓建築學會論文集 : 構造系 Vol.21 No.2

The objective of this study is to evaluate the moment redistribution and plastic rotation of continuous one-way composite slabs reinforced with structural steel decking. A total of 8 two-span continuous slabs with fixed-ends were tested and compared with limit analysis approaches. Theoretical moment capacity and curvature for section subjected to positive or negative moment were calculated by section laminae method. Test results showed that flexural behavior and rotation were greatly influenced by the amount of top bar in negative moment region. Also, the welded wire fabric used as top bar in negative moment region could result in decreasing total load capacity of slabs due to impairing moment redistribution. The predictions, maximum load and plastic rotation capacity, obtained from proposed analysis method were in good agreement with the test results.

변환각 트러스 모델을 이용한 철근콘크리트 깊은 보의 전단 내력 예측

정헌수 중앙대학교 기술과학연구소 2003 기술과학연구소 논문집 Vol.33 No.-

본 연구에서는 철근콘크리트 깊은 보의 전단내력을 예측하기 위하여 전단요소인 압축 스트럿에서 변환각 트러스 모델과 경사 균열면의 국부적인 역학적 거동 및 군열 후 스트럿의 하중수용 능력 등을 함께 고려하기 위해 가상균열 모델을 적용하였다. 전단경간 내의 압축 스트럿에서 기본적인 가정들과 함께 평형방정식, 적합방정식 및 구성방정식 등을 적용하였다. 기존 트러스 모델들과 달리 경사 균열면에서 의 전단전달 능럭, 경사 균열 폭의 진전과 함께 발생하는 국부 변형률, 주 응력방향과 주 작용응력 방향의 차이각에 대한 회전, 균열 면에서의 인장응력 전달능력 및 파괴모드 등을 모두 고려하였다 특히, 기존 모델들과 달리 본 모델에서는 x축 방향과 y축 방향의 수직응력에 대한 경계 조건을 적용하였다. 본 모델은 경사 균열내력 및 극한 전단내력에 대해서 실험 값 대비 각각 평균 1.2, 표준편차0.35와 평균 0.9, 표준편차0.25로서 RA-STM이나 MCFT에 비해서 실험값과 비교적 잘 일치하고 있었다. There have been various models to dffectively explain the shear at the region that the internal stress is disturbed by abrupt change of cross section or concentrated load. However, these models basically assumed pure shear at web, did not consider the crack widths at compression strut, and did not properly describe the local mechanism of principal diagonal cracks at compression strut. Thus, based on the existing models and experimental results provided by various researches, this study presents a new model and evaluates the shear strength of deep beams. The new model combined the transformation angle truss model and cohesive crack model. The validity of the proposed method is illustrated by the comparison of the analytical and experimental results.

초퍼제어-직류전동기의 PSPICE 컴퓨터 시뮬레이션

元忠淵,梁承浩,金德憲,金世燦 成均館大學校 科學技術硏究所 1992 論文集 Vol.42 No.2

In this paper, the authors describe the equivalent circuit for a DC motor in consideration of both magnetic saturation and armature reaction phenomena. To develop DC motor model in PSPICE is to eliminate the gap between drive electronics and models of driven machine. On the basis of these results the dynamic characteristics of a MOSFET chopper controlled DC series motor are investigated by PSPICE simulation and experiment.