• 대한교통학회지
• /
• 제27권1호
• /
• pp.143-155
• /
• 2009

현재 이용되는 모든 동적 통행배정모형들은 출발시간을 기준으로 기종점간의 통행량을 정의하고 있다. 하지만, 동적 OD가 출발시간을 통행수요의 동적 기준점으로 이용하는 것은 동적 통행배정 모형의 계산상 편의를 위한 것이다. 즉, 통행이 활동참여를 위해 발생하고 종료된다는 것을 고려하면 이러한 출발시간 기준 기종점표는 모든 종류의 통행들에 적용될 수는 없다. 예를 들어, 오전의 출근통행은 업무개시시간을 고려한 희망도착시간이 기준시간이 되고, 통근자들이 가정을 떠나는 출발시간은 희망도착시간과 예상 기종점 통행시간을 고려해 결정되는 것이다. 그러나 현재 개발되어 있는 모든 통행배정기법들은 출발시간으로부터 시간의 흐름에 따라 기점에서 종점으로 통행을 이동시키기 때문에 통행수요를 종점 희망도착시간을 기준으로 역방향계산을 할 수 없다. 따라서 현실과 동일한 결정과정을 통해 동적 통행배정을 할 수 있는 모형은 아직 개발되지 않았다. 본 연구에서는 이러한 문제인식 아래 희망도착시간을 기준으로 정의된 동적 기종점표를 교통망에 부하할 수 있는 동적 통행배정모형을 개발하였다. 개발된 모형은 희망도착시간분포와 예상 경로 통행시간을 이용하여 출발시간분포를 갱신하는 방법을 이용하였으며, GLS함수를 통해 수학식을 구성하였다. 개발된 모형은 두 가지의 소규모 교통망들에 적용되어 그 성능을 확인하였다.

• 한국군사과학기술학회지
• /
• 제16권5호
• /
• pp.653-658
• /
• 2013

For towing the new type armored vehicle and maintaining the close support, the armored recovery vehicle(ARV) with winch and crane has been developed. In case of crane, it is mainly used to salvage heavy objects by rotational and vertical motion. Especially, the crane bracket is very important parts due to fixing the ARV's body and rotary joint and preventing the force rotation of crane. Therefore, the crane bracket needs to have an enough strength to endure the high load and it is very important to analyze the stress distribution under loads. In the present work, the experimental and analytical investigation on structural integrity evaluation of crane bracket were carried out. The simulation of three-dimensional finite element method(FEM) was compared with experimental datum. From the numerical results, the FEM simulations corresponded well with th experimental results and the structural safety was confirmed by safety factor.

• 한국미생물·생명공학회지
• /
• 제32권1호
• /
• pp.11-15
• /
• 2004

본 연구에서는 C. diphtheriae toxin-A(DTA)를 합성하는 유전자를 tetracycline derivative인 doxycycline에 의해 발현이 유도되는 plasmid('Tet-on' system)에 삽입시켜, 이를 mouse ES cell에 도입시켰으며, 이렇게 제작된 mouse ES cell이 doxycycline의 처리 농도에 따라 mouse ES cell내의 DTA의 발현이 유도되어 이 결과 세포 사별(apoptosis)을 유발시키는 것을 MTT assay를 통해 확인하였다.

• 한국보건간호학회지
• /
• 제22권1호
• /
• pp.121-130
• /
• 2008

Purpose: Immunization is one of the simplest and most effective approaches for protecting the health of children from preventable infectious disease. This study assessed the immunization statuses of children presenting to childcare centers in Korea and compared the sociodemographic factors of children with age-appropriate immunization for DTaP4 with those with delayed immunization for DTaP4. Method: A national mail survey was used to collect data on the children's immunization history and sociodemographic information. A total of 248 mothers returned completed questionnaires for their children. Results: The overall immunization coverage for HepB, a series of DTaP and polio and varicella was above 95%. However, the percentage of age-appropriate immunizations of vaccines ranged from 45.3% to 69.0% depending on the vaccines. Only the age of the child was a significant factor for delayed immunization for DTaP4. Conclusion: To fully protect children from vaccine-preventable disease, childcare providers can playa role in monitoring the immunization statuses of children in their care centers to ensure that they all receive all childhood immunizations on time.

• 한국소음진동공학회논문집
• /
• 제26권7호
• /
• pp.774-780
• /
• 2016

In this paper noise source and transfer path of tactical vehicle are analyzed with partial coherence function and spectrum analysis. Engine, transmission, structure panel and aerodynamic are main source of cabin noise. To reduce cabin noise, identifying transfer path of sources and analyzing their contribution is important. With modeling of transfer path and partial coherence function, transfer path and principal noise source can be identified. Engine/transmission and structural resonance are principal source of low frequency noise and by adding stiffener and sound absorbing material, resonance of vibration and inflow air problem can be solved.

• 한국소음진동공학회논문집
• /
• 제26권4호
• /
• pp.365-374
• /
• 2016

The underwater radiated noise can be reduced by decreasing the structure borne noise of the on-board equipment. Therefore, the structure borne noise of the onborad installed equipment is strongly restricted by ROK navy with MIL-Std 740-2. Usually, the vibration transmissibility from the equipment to the hull of the ship is dependent on its mount characteristics. Even though the double mount structure is proper to apply for ship board application rather than single mount, it is not widely applied due to the weight and volume resriction of the ship. Therefore, in this research, the base using sandwitch panel which can act as double mount structure is suggested and its noise reduction capacity is verified with analytic calculation as well as experiment.

• 한국소음진동공학회:학술대회논문집
• /
• 한국소음진동공학회 2011년도 추계학술대회 논문집
• /
• pp.803-808
• /
• 2011

The shipboard working environment of navy vessel is very inferior to the ground working environment. For this reason, the crew of a navy vessel suffer from an occupational disease such as lumbar pain, hearing loss, etc. Although standard for navy vessel's environmental vibration is applied, the criterion of the environmental vibration is too high. So it doesn't help to improve habitability of crew. In this study, for improving its habitability of crew, the current vibration level of navy vessel was examined and the standard of navy vessel's environmental vibration was investigated.

• 한국소음진동공학회:학술대회논문집
• /
• 한국소음진동공학회 2011년도 추계학술대회 논문집
• /
• pp.797-802
• /
• 2011

Vibration of diesel engines in naval vessels causes structure vibration which is significant under water radiating noise source under CIS (Cavitation Inception Speed). So managing the vibration level of diesel engine is important for survivability and also durability of naval vessels. Therefore, in this research, a vibration criterion which is applied for Korean naval vessels are reviewed. It is compared with the DNV, ABS and merchant ship's diesel engine criteria. And also vibration data of three Korean naval vessels are analyzed. As a result, reasonable criteria of diesel engine vibration and shipbuilding standards are suggested.

• 한국소음진동공학회논문집
• /
• 제24권5호
• /
• pp.407-413
• /
• 2014

The diesel engine and reduction gear combination is one of the common propulsion system in a naval vessel. Since the diesel engine has torsional vibration caused by reciprocating motion of the mass and gas pressure force of the cylinder, high cycle torsional fatigue can be occurred. Therefore, ROK navy restricts the maximum stress of the propulsion shaft according to MIL G 17859D. In this paper, the root cause for the failure of the diesel engine and reduction gear connecting shaft occurred in typical naval vessel is investigated based on the measured bending and torsional moment according to MIL G 17859D procedure.

• 한국고분자학회지:고분자과학과기술
• /
• 제4권5호
• /
• pp.387-397
• /
• 1993