지반의 진행성 파괴와 기초의 크기 효과를 고려한 지지력 특성에 관한 실험적 연구

임종철,안민홍,홍석우,강정철,여종인 釜山大學校生産技術硏究所 1999 生産技術硏究所論文集 Vol.56 No.-

얕은 기초의 지지력을 산정하는데 있어서 기존 이론의 지지력계수(Nc,Nr,Nq)는 흙의 내부마찰 각 φ만의 함수로 표현되어져 있다. 그리고 조밀한 모래지반에서는 동시파괴(전반전단파괴)가 발생한다고 가정하고 있다. 본 논문에서는 주문지 표준사를 이용하여 중간·조밀한 모래지반을 제작하여, 재하폭 B를 변화시켜 실험하였다. 실험 결과, 조밀한 모래지반에서도 진행성파괴가 발생하며, 지지력계수 Nr의 평가에 있어서 내부마찰각 φ뿐만 아니라, 재하폭 B의 영향이 고려되어져야 함을 알 수 있었다. The bearing capacity factors(Nc,Nr,Nq) of an existing formulae are the function of only internal friction angle(φ) in calculating of ultimate bearing capacity of shallow foundations. And it is assumed that the simultaneous failure(general shear failure) occurs in the dense sand. In this study, the medium to dense sand grounds are formed by Joomunjin standard sand, and the laboratory medel tests are made with the change of load-width(B). By test it is known that the progressive failure is also occurred in the dense sand ground and so the bearing capacity factor(Nr) should be considered for not only internal friction angle(φ) but also the effect of load-width(B).

中.長距離 달리기의 最適戰略에 關한 數理的 模型

洪盛杓,全鍾貴,崔哲圭 忠南大學校體育科學硏究所 1988 體育科學硏究誌 Vol.6 No.1

The mathematical theory of competitive running by Keller, which is based on the Newton's second law of motion, is applied to analyze the track records of the Asian and Korean athlets. In addition, the empirical formular proposed by Toots is used to represent the aver age speed of the runners for various races. The main conclusions arrived at are as follows. 1. According to the Keller theory, running at a constant speed is an optimum strategy throughout the races except the initial two seconds and the final 3 seconds, approximately, for distances greater than certain critical distances. But it is effective to run at a full speed with maximum propulsion, for the short distance sprints. 2. The critical distances obtained from the records are 291m for the World records, and 298 (320m for women) and 303m (330m for women) for Asian and Korean records, respectively. Thus the 400m race may be considered the reference item for the mid-range race. 3. Korean athletes show rather inferior physiological characteristics for the most cases analyzed, with the only exception for the oxygen supply rate of male athelets, which is somewhat greater than that of the Asian records. This may indicate a passilility of future development of superior mid and long distance runner from Korean athletes.

Creutzfeldt-Jacob병 1례

홍승철,한진희,정종현,김소양,허균,이성필 大韓神經精神醫學會 1998 신경정신의학 Vol.37 No.1

저자들은 Creutzfeldt-Jacob병 1례를 경험하였기에 문헌고찰과 함께 보고하는 바이다. 환자는 약 4개월에 걸친 비교적 짧은 기간 동안 중증의 인지 기능 장애와 시각 장애, 보행장애와 하지의 약화, 불수의적 운동 등과 함께 섬망상태에까지 이르게 되어 본원 정신과에 입원하게 되었다. 정신상태 검사상, 반응시간의 지체, 언어장애와 보속증, 시간에 대한 지남력 장애, 주의 집중력 장애, 단기 및 장기 기억 장애, 추상적 사고능력 장애 등의 소견을 보였고, 이러한 증상들은 입원후 치료에도 불구하고 빠르게 악화되었다. 뇌파검사상 지속적인 다발초점성 서파가 모든 전극에서, 특히 우측 전두부에서 현저하게 나타나는 소견을 보였고, 병리조직학적 검사상 대뇌 피질에 신경손실을 동반한 해면화와 신경교 증식증을 나타냈다. 이상의 소견들은 모두 CJD의 진단에 합당하였다. We report a case of Creutzfeldt-Jacob disease and review the relevant literatures. This 56-year-old male patient was admitted to our hospital with a history of rapidly progressing cognitive dysfunction, visual disturbance, gait disturbance, weakness, involuntary movement of lower extremities, and the symptoms of delirium. On mental status examination, he showed psychomotor retardation, speech disturbance, perseveration, disorientation, impairment of short-term and long-term memory, and inability of abstract thinking. He had a rapid downhill course, along with shakiness of trunk, rigidity of the limbs, myoclonus, confusion, and finally, inability to speak or move on the bedside. On electroencephalogram(EEG), continuous multifocal show delta activities were found in all leads, especially in the right frontal areas. Brain biopsy showed, spongiosis with neuronal loss and gliosis noted at the cerebral cortex. These findings were compatible with Creutzfeldt-Jacob disease.

Lyapunov 제2방법에 의한 로보트 머니플레이터의 적응제어

홍철호,이택종 成均館大學校 科學技術硏究所 1989 論文集 Vol.40 No.1

본 논문에서는 머니플레이터의 nominal제이에 근거를 둔 기준 모델 추종 적응제어기법(Adaptive model following control)을 제안한다. 기준 모델은 머니플레이터의 Nominal 값들을 사용하여 머니플레이터의 모델과 유사한 비선형커플링 시스템으로 표현하며 로봇 머니플레이터가 미리 계획된 궤적을 최대한 근접하게 추종하도록 비선형 보상과 Lyapunov 제 2방법에 의해 대국적으로 점근안정하도록 구현된다. 제안된 제어칙(Control law)은 컴퓨터모사를 통해 그 성능의 효용성을 입증된다. This paper proposed AMFC based on nominal control scheme of a robot manipulator. Reference model is represented by a nonlinear coupled robot manipulator using its nominal values. Control lane is developed for the manipulator to track a preplanned trajectory as closely as possible and is designed to assure globally asymptotic suability via the second method of Lyapunov. The performance validity of the proposed control law is verified by computer simulation.

정신병적 증상이 동반된 기면병 1예

홍승철,송정민,정종현,권용실,한진희,이성필 大韓神經精神醫學會 2003 신경정신의학 Vol.42 No.5

Narcolepsy is a sleep disorder characterized by excessive daytime sleepiness, cataplexy, sleep paralysis, hypnagogic hallucinations and disrupted nocturnal sleep. We report a patient with a diagnosis of schizophrenia who was subsequently diagnosed as narcolepsy. A case of a 22-year-old woman with concomitant narcolepsy and psychotic symptoms was discussed from a perspective of the diagnosis and therapeutic challenges, particularly on pharmcological treatment dealing with issues raised by their coexistence.

Sisomicin고생산 균주의 예비선별과 이들의 생리적 특성

洪淳德,金鐘國,李相瀚,河相哲 慶北大學校 1991 論文集 Vol.51 No.-

In order to isolate selectively sisomicin over-producers during mutagenesis, several conditions required for fragmentation, mutagen treatment, and selection of mutants were examined. As a result, up to 30% yield-up of the antibiotic production of a candidate was achieved. For the step of scale-up, effect of antifoaming agent in small scale with flasks was studied. Palm oil was very effective within the range of without inhibiting of growth. Water addition during the fermentation enhanced 10% of sisomicin productivity than that of control.

지반개량앵커(SI 앵커)의 개발과 현장에의 적용

홍석우,주인곤,임종철 釜山大學校生産技術硏究所 1996 生産技術硏究所論文集 Vol.50 No.-

그리운드 앵커의 시공이 나날이 증가되고 있는 현실에서, 연약한 지반에도 시공 가능한 지반개량앵커(SI 앵커)의 정확한 극한인발력의 산정과 인발저항기구를 연구하는 일은 매우 중요한 일이다. SI 앵커는 지반개량앵커를 의미한다. 앵커를 지지하는 지반을 J.S.P 로 개량한 짓이다. SI 앵커는 인발저항기구를 알기 위해 SI 앵커체의 표면과 앵커체 두부의 응력을 측정하는 것이 필요하다. 본 연구에서는 현장실험과 실내모형실험을 통해 SI 앵커체 표면에서의 응력을 측정했고, 산정식에 의한 계산 결과치와 비교했다. 본 연구의 결론은 다음과 같다. (1) SI 앵커의 거동은 일반 마찰방식 앵커의 거동과는 다르게 나타나는데, 이는 SI 앵커의 저항력은 지압저항력과 마찰 저항력의 합에 의해 결정되기 때문이다. (2) SI 앵커의 설계 시는 진행성 파괴의 영향을 고려하여야 한다. (3) SI 앵커의 지압저항에 의해 앵커두부의 변위는 감소되고, 앵커의 극한인발력은 일반마찰방식앵커에 비해 증가한다. (4) SI 앵커는 일반앵커가 시공되기 어려운 연약지반 내에 정착할 때 특히 효과적이다. Day after day, use of ground anchor is increasing in execution, It is significant to calculate the ultimate pullout force exactly and to research the mechanism of pullout resistance of SI anchor. SI anchor means the Soil Improvement anchor. Ground for anchoring is improved by J. S. P. In order to analyze the mechanism of pullout resistance of SI anchor, it is necessary to measure stresses on the SI anchor surface and SI anchor head. In this study, we measured stresses on the SI anchor surface by field tests and laboratory model tests and compared with calculated results. The conclusions of this study are as follows: (1) The behavior of SI anchor is different from that of friction anchor, because pullout resistance of SI anchor is made by bearing and frictional force. (2) In the design of SI anchor, progressive failure should be considered. (3) By the bearing resistance of SI anchor. the displacement of anchor head is decreased and the ultimate pullout force of anchor is increased comparing with general friction anchor. (4) SI anchor can be used in soft ground effectively.

약품활성화와 가스활성화에 대한 왕겨로부터 활성탄의 제조

홍종철,김명수 명지대학교 대학원 1998 대학원논문집 Vol.2 No.-

A series of activated carbons was prepared from rice hulls by both chemical activation with KOH and physical activation with steam and carbon dioxide. The effect of process variables such as carbonization, activation temperature, and chemical ratio on the pore structure and activation yield of the carbons was studied. When the char produced by the carbonization of the rice hulls in a stream of nitrogen at 700 ℃ was well mixed with a concentrated solution of potassium hydroxide at a KOH:char ratio of 4:1 and then the mixture was activated for 3 hours in a stream of nitrogen, high-quality activated carbons with high surface area, high pore volume, and well-developed pore structure could be prepared. The surface area and micropore volume of the chemically activated carbon were 2∼3 times higher than those obtained by physical activation.

대구지역의 오존농도와 영향인자

홍성철,장봉기,이종영,조재미 순천향대학교 기초과학연구소 1998 순천향자연과학연구 논문집 Vol.4 No.1

This study was carried out to estimate the ozone concentration to behaviour and the factors influencing the variation of its concentration in the ambient air in Taegu. Measurements of ozone concentrations were made at 5 monitoring station to take care of Taegu Regional Environment Department during January 1996 to December 1996, also measured the hourly average concentration of sulfur dioxide(SO₂), total suspended particulate(TSP), nitrogen dioxide(NO₂), carbon monoxide(CO) and meteorological factors, that is temperature, relative humidity, wind velocity, wind direction, precipitation, insolation intensity etc, for the same period at same place. The basis of the data obtained were analyzed statistically along with the various data. The results were as follows. 1. The annually arithmetic mean concentration of ozone for the 5 sites during one year was 13.5ppb and ranged from 11.0±12.9ppb at Nowon site to 14.6±14.2ppb at the Sankyeuk site. 2. The frequency of hours on which ozone concentrations exceeded the present short term(1 hour) standard of ozone(100ppb) were eight times. 3. The diurnal pattern of hourly ozone concentration in Taegu area was that the maximum hourly concentration of ozone occurred between 3 and 4 p.m. in a day and concentrations at night were very low and the minimum hourly concentration of ozone was observed at around 7 a.m. 4. The weekly variation of ozone concentration was that the higher level ozone concentration in the day of the week occurred from thursday to friday but the lower level was observed from saturday to monday. 5. The monthly variation of ozone concentration was that the higher level in summer and the lower level in winter, exceptionally ozone concentration in July was very low. 6. The ozone concentration had negative correlations with the concentration of other primary pollutants(SO₂, NO₂, CO, TSP) in simple regression analyses. 7. The ozone concentration was positively correlated to temperature, wind speed, insolation intensity and insolation duration but negatively correlated to relative humidity, cloud quantity. 8. The results of multiple regression analysis on on-time the ozone concentration to other pollutants and meteorological factors, R²was ranged from 0.41 to 0.50. 9. In multiple regression analysis to predict short-time(1 hr) ozone concentration after 1 hour to the pollutants including on-time ozone and meteorological factors, R²was ranged from 0.87 to 0.91. 10. The multiple regression model could be a potentially useful tool for air pollution forecasters in predicting ozone concentration after 1 hour in Taegu.

지반과 앵커체의 탄성계수비 (E_(a)/E_(r))에 따른 앵커체 표면에서의 응력전이에 관한 수치해석

홍석우,임종철,고호성 부산대학교 1999 生産技術硏究所論文集 Vol.56 No.-

Anchor is used for a restraining of a ground deformation in the retaining wall, slope-stability et ect. When pullout load is applied to the anchor in the ground, the behavior of the anchor in the ground is differed by the rigidity of anchor body and ground. In this study, the stress-behavior is analyzed by the numerical a analysis on the surface of an anchor body according to the pullout of an anchor. Mostly, The analysis is focused on the change of a shear stress according to the coefficient ratio of elasticity. The coefficient ratio of elasticity(E_(a)/E_(r)) is defined by the ratio between elastic modulus of ground(E_(r)) and that of anchor body (E_(a)). By using this ratio, the progressive failure of anchor body can be analysed. 앵커는 흙막이 벽, 사면안정 등에서 사용되는 지반변형 억제공법이다. 앵커가 지중에서 인발하중을 받으면 앵커체의 강성과 지반의 강성에 따라 각각 다른거동을 하게 된다. 본 논문에서는 인장형 및 압축형 앵커의 인발에 따른 표면에서의 응력거동을, 주로 탄성계수비에 따른 전단응력의 변화에 중점을 두고 수치해석 기법을 이용하여 분석하였다. 여기서, 탄성계수비(coefficient ratio of elasticity)란 지반탄성계수(E_(r))와 앵커체탄성계수(E_(a))의 비 (E_(a)/E_(r))를 말하는데, 이 탄성계수비에 의해 앵커의 진행성 파괴에 대한 영향을 평가할 수 있다.