• Magazine of the Korea Concrete Institute
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• v.11 no.1
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• pp.255-266
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• 1999

The objective of this experiment is to observe the elastic and inelastic behaviors of high-rise reinforced concrete frames having non-seismic details. To do this, a building frame designed according to Korean seismic code and detailed in the Korean conventional practice was selected. A 1:12 scale plane frame model was manufactured according to similitude law. A reversed lateral load test and a monotonic pushover test were performed under the displacement control. To simulate the earthquake effects, the lateral force distribution was maintained to be an inverse triangle by using a whiffle tree. From the tests, base shears, crack pattern, local rotations in the ends of critical members and the relations between interstory drift versus story shear are obtained. Based on test results, conclusions are drawn on the implications of the elastic and inelastic behaviors of a high-rise reinforced concrete frame having non-seismic details.

• Health Policy and Management
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• v.5 no.1
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• pp.161-191
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• 1995

본 논문은 서구의 이론을 바탕으로 개발된 직무만족도에 관한 인과모형을 한국의 병원근무자들을 대상으로 실증적으로 검증하고 직무만족도를 결정하는 인과적 요인들을 파악하는데 목적이 있다. 본 모형의 종속변수는 직무만족도이고 독립변수로는 3개집단의 변수들로 크게 분류하여 선정되었는데 첫째, 사회적 변수들로써 직무의 자율성, 직무의 모호성, 직무 갈등, 직무의 양, 상사 및 동료와의 관계, 발전가능성, 직무의 단순성, 분배정의, 승진기회, 물리적 근무환경, 임금 등이며, 둘째, 심리적 변수들로써 기대 충족도, 근무의욕, 적극적 심성, 부정적 심성 등이고, 셋째, 환경적 변수들로써 외부 취업기회와 가족에 대한 책임 등이 사용되었다. 또한 독립변수들이 종속변수에 영향을 미치는데 있어 개인의 가치관이 어떻게 작용하는지도 검증하였다. 자료수집을 위해 대구에 위치한 750병상 규모의 한 대학병원에 근무하는 전직원을 대상으로 자기가 입식 설문조사를 실시하였으며 879매가 회수되어 74.7%의 응답율을 기록하였다. 수집된 자료중 사용 가능한 836명의 응답을 바탕으로 선형구조관계분석(LISREL)과 다중회구분석기법을 이용하여 인과 모형을 검증하였다. 분석결과 직무만족도에 유의한 영향력을 가지는 변수들은 직무의 모호성, 직무의 모호성, 동료관계, 직무의 단순성, 분배정의(이상 시회적 변수), 기대의 총족도, 근무의욕, 적극적 심성, 부정적 심성(이상 심리적 변수), 외부 취업기회(환경적 변수) 등인 것으로 나타났으며 개인의 가치관과 인구학적인 변수들은 직무만족도에 큰 영향을 미치지 못하는 것으로 나타났다. 또한 본 연구에서 사용된 인과모형은 직무만족도의 변이를 75.4% 설명함으로서 기존의 다른 모형들 보다 높은 설명력을 나타내었다. 결론적으로 본 연구에서 사용된 직무만족도의 인과모형은 한국의 조직에서도 적용이 가능한 것으로 보이며, 또한 직무만족도의 일반적 모형은 구조적 변수, 심리적 변수, 그리고 환경적 변수들을 모두 포함하는 포괄적인 모형이 타당하다는 결론을 얻을 수 있었다.

• Magazine of the Korea Concrete Institute
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• v.8 no.2
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• pp.139-150
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• 1996

The objective of this study is to provide the information on the manufacturing and exper- , ructures. imental techniques of small scale modeling of precast concrete(P.C.) large panel :-t The ad~~pted scale was one-fifth. 4 types of experiments were performed : nlaterial tests for model concrete and model reinforcement, compressive test of horizontal joint, shear test of vertical joint and cyclic static test of 2-story subassemblage structure. Based on the experimental results, the following conclusions are drawn : i 1) Model concrete had in general larger compressive strength than expected. (2) Model reinforcement showed less ductility if the annealing processes were performed without using vaccuum tube. 131 Failure niotles of horizontal and vertical joints were almost same for both prototype and model. But the strength of model appears to be higher than required by similitude law. (41 Hysteretic behavior of 1 /T, scale subassemblage model can be made quite similar to that of prototype if the ductility of model reinforcement and compressive strength of model concrete could be representative of those of prototype.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.39 no.1
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• pp.55-61
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• 2019

To improve bus service quality and passengers' safety at bus stops, it is necessary to analyze the relationship between bus stopping behaviors and bus stop conditions. Thus, this study investigated the proper stopping rate at 31 bus stops on Central Boulevard in Busan metropolitan city and analyzed the relationship between the proper stopping rate and bus stop operating conditions such as the length of berth, the distance from the front line of berth to bus shelter and so on. The analysis results show that the proper stopping rate is 45.82 % and the rates are closely related to each bus stop operating condition. Therefore, it is highly recommended that the front line of berth should be located parallel to bus shelter for improving the safety of bus passengers. In addition, it is suggested that the length of berth should be longer than 15m and the pavement marking of berth be redesigned with dash lines to take account of buses' entering and leaving the berth.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.20 no.2
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• pp.157-167
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• 2008

The aeration of an overtopping wave on a vertical structure generated by a plunging wave was investigated through laboratory measurements of void fraction. The overtopping wave occurring after wave breaking becomes multi-phased and turbulent with significant aeration, so that the void fraction of the flow is of importance. In this study, fiber optic reflectometer and bubble image velocimetry were employed to measure the void fraction, velocity, and layer thickness of the overtopping flow. Mean properties were obtained by ensembleand time-averaging the repeated instantaneous void fractions and velocities. The mean void fractions show that the overtopping wave is very high-aerated near the overtopping wave front and relatively low-aerated near the deck surface and rear free surface of the wave. The flow rate and momentum of the overtopping flow estimated using the measured data show that the void ratio is an important parameter to consider in the multiphase flow. From the similarity profiles of the depth-averaged void fraction, velocity, and layer thickness, one-dimensional empirical equations were obtained and used to estimate the flow rate and momentum of the overtopping flow.

• Journal of the Korean Society of Marine Environment & Safety
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• v.26 no.6
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• pp.742-750
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• 2020

The flow noise generated by hull appendages is directly related to the performance of the sonar in terms of self-noise and induces a secondary noise source through interaction with the propeller and rudder. Thus, the noise in the near field should be analyzed accurately. However, the acoustic analogy method is an indirect method that is not used to simulate the propagation of an acoustic signal directly; therefore, diffraction, reflection, and scattering characteristics cannot be considered, and near-field analysis is limited. In this study, the propagation process of flow noise in water was directly simulated by using the lattice Boltzmann method. The lattice Boltzmann method could be used to analyze flow noise by simulating the collision and streaming processes of molecules, and it is suitable for noise analysis because of its compressibility, low dissipation rate, and low dispersion rate characteristics. The flow noise source was derived using Reynolds-averaged Navier-Stokes equations for the hull appendages, and the propagation process of the flow noise was directly simulated using the lattice Boltzmann method by applying the developed flow-acoustic boundary conditions. The derived results were compared with Ffowcs Williams-Hawkings results and hydrodynamic pressure results based on the receiver location to verify the usefulness of the lattice Boltzmann method within the near-field range in comparison with other techniques.

• Korean Institute of Interior Design Journal
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• v.13 no.5
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• pp.206-214
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• 2004

본 연구는 사무공간에 영향을 주는 물리적 환경 요소 (공간, 가구배치, 미, 주변요소)를 제시하고 각 환경 요소들과의 관계를 파악하며 각 물리적 환경요소들과 직업 만족도 (급여, 진급, 책무, 상사와의 관계, 물리적 공간과 배치, 수업방법의 향상, 현재 직업 만족도)와의 관계를 분석하는데 연구의 목적이 있다. 또한 물리적 환경 요소들, 직업 만족도와 개인 신상 (나이, 성별, 지위, 교육수준, 교육 경력) 의 특성들과의 상관관계를 알아보고자 한다. 본 연구는 오클라호마 주립대학교의 종신 재직권을 가진 교육대학 교수들을 대상으로 세 가지 가설을 바탕으로 작성된 설문지를 배포하여 조사되었다. 각 교수들의 사무공간은 1997년에 개보수를 마치고 그 해 여름부터 사용하고 있다. 설문은 현재 사용하고 있는 사무공간에 대한 평가, 직업 만족도에 대한 평가와 개인 신상의 특성에 대한 질문으로 조사되었다. 조사 결과 사무공간에 영향을 주는 물리적 환경 요소들 간에 밀접한 관계가 있다는 가설이 입증되었고, 또한 조사 결과 물리적 환경의 만족도가 증가할수록 직업만족도가 증가하는 것으로 물리적 사무환경에 대한 만족도와 직업에 대한 만족도가 직접적인 관계가 있다는 가설 또한 확증되었다. 물리적 환경요소, 직업 만족도와 개인 신상의 특성들과의 상관관계가 있다는 가설은 전체적으로는 입증되지는 않았지만 부분적으로 요소들 간에 관계를 보여주고 있다. 남성이 여성보다 가구배치에 대해 불만족스러웠고 교육경력이 적을수록 사무공간의 냉난방과 환기에 대한 불만족을 보였다. 본 연구의 결과는 교수들의 사무환경의 부정적, 긍정적 견해를 지각하여 사무 환경의 질을 높이는데 도움이 되는데 중요한 역할을 할 수 있겠다. 본 연구는 교육대학의 교수들에 국한되어 있었던 바 추후에는 전체 교육자들을 대상으로 장기간의 관찰을 통한 연구가 요구되어 진다.신만의 고유한 해결책으로 발전시키는지를 고찰하고자 한다. 본 논문의 목적은 서울을 사례분석 중 하나로 사용하여 인테리어 디자인 분야의 경계를 대도시로 확장하는 동시에 새로운 적용영역의 가능성을 탐구하는데 있다 하겠다.[C/N]의 값을 나타내었다.다.다.화 기술, 구동방법등에 대한 기술개요와 국내외 기술동향에 대하여 소개하고자 한다.었다.다._{2}$가 0.25[wt%] 첨가된 시편의 20[.deg.C]에서의 유전상수는 16,700으로 최대값을 유전손실을 1.28[%]로 최소값을 나타내었다. 또한 모든 시편은 온도 및 주파수에 따라 유전상수가 완만하게 변화하는 유전이완 특성을 나타내었다.다.수적인 물의 양에 따른 DIAION WA30의 라세미화 효율에 관하여 실험한 결과, 물의 양이 증가할수록 그 효율은 감소하였다. DIAION WA30을 라세미화 촉매로 사용하여 아이소옥탄 내에서 라세믹 나프록센 2,2,2-트리플로로에틸 씨오에스터의 효소적 DKR 반응을 수행해 보았다. 그 결과 DIAION WA30을 사용하지 않은 경우에 비해 반응 전환율과 생성물의 광학 순도는 급격히 향상되었다. 전통적 광학분할 반응의 최대 50%라는 전환율의 제한이 본 연구에서 찾은 DIAION WA30을 첨가함으로써 성공적으로 극복되었다. 또한 고체 염기촉매인 DIAION WA30의 사용은 라세미화 촉매의 회수 및 재사용이 가능하게 해준다.해준다.다. TN5 세포주를 0.2 L 규모 (1 L spinner flask)oJl에서 세포간의 응집현상 없이 부유배양에 적응,배양시킨 후 세포성장 시기에 따른 발현을 조사한 결과 1 MOI의 감염조건 하에서는 $0.6\times10^6$cell/mL의 early exponential시기의 세포밀도에서 72시간 배양하였을 대 최대 발현양을 나타내었다. 나타내었다.

• Journal of the Korean Society of Marine Environment & Safety
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• v.19 no.5
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• pp.525-530
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• 2013

In this study, the generator engine of training ship M/S "HAE RIM" of Kunsan National University which is being operated for 20 years was used in the experiment. The experiment was carried out under the engine speed of 1200rpm, then the load was varied 30 kW intervals from 0 to 90 kW and the injection timing was varied $2^{\circ}$CA intervals from BTDC $19^{\circ}$ to $23^{\circ}$CA. In the case of advancing fuel injection timing from BTDC $21^{\circ}$CA to $23^{\circ}$CA, specific fuel consumption is decreased by 1.37%, NOx is increased by 11.59 %, soot is decreased by 23.5 % and $SO_2$ is decreased by 2.8 %. Accoring to the analysis of effects of fuel injection timing on combustion & exhaust emissions characteristics on an old marine diesel engine, it is proved that the optimum fuel injection timing is BTDC $23^{\circ}$ which is $2^{\circ}$ faster than that of original injection timing.

• Journal of Korean Tunnelling and Underground Space Association
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• v.20 no.6
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• pp.1061-1071
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• 2018

A subsea tunnel, being a super-sized underground structure must ensure safety at the time of earthquake, as well as at ordinary times. At the time of earthquake, in particular, of a subsea tunnel, a variety of response behaviors are induced owing to relative rigidity to the surrounding ground, or difference of displacement, so that the behavior characteristics can be hardly anticipated. The investigation aims to understand the behavior characteristics switched by earthquake of an imaginary subsea tunnel which passes through a fault zone having different physical properties from those of the surrounding ground. In order to achieve the aim, dynamic response behaviors of a subsea tunnel which passes through a fault zone were observed by means of indoor experiments. For the sake of improved earthquake resistance, a shape of subsea tunnel to which flexible segments have been applied was considered. Afterward, it is believed that a D/B can be established through 3-dimensional earthquake resistance interpretation of various grounds, on the basis of verified results from the experiments and interpretations under various conditions. The present investigation performed 1 g shaking table test in order to verify the result of 3-dimensional earthquake resistance interpretation. A model considering the similitude (1:100) of a scale-down model test was manufactured, and tests for three (3) Cases were carried out. Incident seismic wave was introduced by artificial seismic wave having both long-period and short-period earthquake properties in the horizontal direction which is rectangular to the processing direction of the tunnel, so that a fault zone was modeled. For numerical analysis, elastic modulus of the fault zone was assumed 1/5 value of the modulus of individual grounds surround the tunnel, in order to simulate a fault zone. Resultantly, reduced acceleration was confirmed with increase of physical properties of the fault zone, and the result from the shaking table test showed the same tendency as the result from 3-dimensional interpretation.

• Magazine of the Korea Concrete Institute
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• v.10 no.6
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• pp.241-252
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• 1998

The objective of the research stated herein is to observe the actual responses of a low-rise nonseismic moment-resisting reinforced concrete frame subjected to varied levels of earthquake ground motions. First, the reduction scale for the model was determined as 1 : 5 considering the capacity of the shaking table to be used and the model was manufactured according to the similitude law. This model was, then, subjected to the shaking table motions simulating Taft N21E component earthquake ground motions, whose peak ground accelations (PGAs) were modified to 0.12g, 0.2g, 0.3g, and 0.4g. The lateral accelerations and displacements at each story and local deformations at the critical reginos of the structure were measured. The base shear was measured by using self-made load cells. Before and after each earthquake simulation test, free vibration tests were performed to find the change in the natural period and damping ratio of the model. The test data on the global and local behaviors are interpreted. The model showed the linear elastic behavior under the Taft N21E motion with the PGA if 0.12g, which represents the design earthquake in Korea. The maximum base shear was 1.8tf, approximately 4.7 times the design base shear. The model revealed fairly good resistance to the higher level of earthquake simulation tests. The main components of its resistance to the high level of earthquakes appeared to be 1) the high overstrength, 2) the elongation of the fundamental period, and 3) the minor energy dissipation by inelastic deformations. The drifts of the model under these tests were approximately within the allowable limit.