• 제목/요약/키워드: ManHae

검색결과 570건 처리시간 0.032초

자동차용 엔진오일의 열화도 측정 센서연구 (A Study on Deterioration Measurement Sensor in the Automobile Engine Oil)

  • 김원태;최만용;박해원;박정학
    • 한국정밀공학회지
    • /
    • 제24권3호
    • /
    • pp.61-66
    • /
    • 2007
  • This work is aimed to measure the deterioration in oil sensor. For the study, the circuit of a coil-type oil sensor packaged was developed and applied to the automobile engine for monitoring the deterioration of engine oil in driving conditions. From the principle which the deterioration of automobile engine oil can be expressed to the dielectric constant, the capacitance bridge circuit and the integrator circuit were designed. As results, the range of operating temperature of engine oil was experimentally recommended within $55^{\circ}C$ for the stability of a sensor designed. It was also concluded that the characteristics of output voltage converted from the dielectric constant were linearly distributed and predicted the optimized time for the exchange of engine oil.

가상경계 유한차분 격자 볼츠만 법을 이용한 평판근처 원형 실린 더 주위의 비압축성 유동에 관한 수치적 연구 (A numerical study of the incompressible flow over a circular cylinder near a plane wall using the Immersed Boundary - Finite Difference Lattice Boltzmann Method)

  • 양희주;정해권;김래성;하만영
    • 대한기계학회:학술대회논문집
    • /
    • 대한기계학회 2007년도 춘계학술대회B
    • /
    • pp.2731-2736
    • /
    • 2007
  • In this paper, incompressible flow over a cylinder near a plane wall using the Immersed Boundary. Finite Difference Lattice Boltzmann Method (IB-FDLBM) is implemented. In this present method, FDLBM is mixed with IBM by using the equilibrium velocity. We introduce IBM so that we can easy to simulate bluff-bodies. With this numerical procedure, the flow past a circular cylinder near a wall is simulated. We calculated the flow patterns about various Reynolds numbers and gap ratios between a circular cylinder and plane wall. So these are enabled to observe for vortex shedding. The numerical results are found to be in good agreement with those of previous studies.

  • PDF

비평형 1 차 외삽 경계조건을 이용한 격자 볼츠만 법의 수치적 안정성 및 정확도에 관한 연구 (A Study on the Numerical Stability and Accuracy of Lattice Boltzmann Method with Non-equilibrium first order extrapolation boundary condition)

  • 정해권;김래성;이현구;하만영
    • 대한기계학회:학술대회논문집
    • /
    • 대한기계학회 2007년도 춘계학술대회B
    • /
    • pp.2684-2689
    • /
    • 2007
  • Non-equilibrium first order extrapolation boundary condition proposed by Guo et $al.^{(9)}$ proposed has a good application for complex geometries, a second order accuracy and a treatment on non-slip wall boundary condition easily. However it has a lack of the numerical stability from high Reynolds number. Guo et $al.^{(9)}$ substituted the density value of adjacent nodes for the density of boundary nodes. This procedure causes the numerical instability on the boundary. In this paper, we derived a procedure of density extrapolation and compared to previous results.

  • PDF

센서네트워크를 위한 홉간 순서 번호를 이용하는 신뢰성 있는 데이터 전송 지원 기법 (A Reliable Transport Support Using Hop-by-hop Sequence Numbers for a Wireless Sensor Network)

  • 이해준;고양우;이동만
    • 한국정보과학회:학술대회논문집
    • /
    • 한국정보과학회 2005년도 가을 학술발표논문집 Vol.32 No.2 (1)
    • /
    • pp.178-180
    • /
    • 2005
  • 최근 센서네트워크에서는 코드 분배과 같이 신뢰성 있는 전송을 요구하는 새로운 기능들이 추가 되고 있다. 이를 위한 기존의 프로토콜은 센서노드 간의 높은 전송 실패율 때문에 홉간 손실 복구 기법을 제안하였다. 하지만 기존 프로토콜은 홉간 손실 복구를 위해 종단간 세션의 정보를 사용하기 때문에 모든 중간 노드들이 최근 받은 패킷의 순서 번호 같은 정보를 알고 있어야만 한다. 만약, 세션 중간에 경로가 바뀌어서 새로운 노드가 참가하게 된다면 기존 프로토콜은 잘 동작할 수가 없다. 본 논문은 홉간 순서 번호 기반의 손실 복구 기법인 HRS를 제안한다. 홉간 손실 복구에서는 종단간 세션의 순서 번호 대신에 홉간 순서 번호가 사용되기 때문에 중간 노드는 종단간 세션의 정보 없이도 손실복구에 바로 참가 할 수 있다. 시뮬레이션을 통해 제안하는 기법이 세션 중간에 경로 변화와 상관없이 잘 동작하고 경로 변화가 없더라도 기존의 프로토콜보다 대부분의 기준에서 우수하다는 것을 보였다.

  • PDF

실시간 대화형 화산재 확산 예측 시스템 개발 (Developing Interactive Simulator for Predicting Volcanic Ash)

  • 김해동;이호만
    • 한국환경과학회지
    • /
    • 제23권3호
    • /
    • pp.527-532
    • /
    • 2014
  • According to the analysis of volcanic observation data around Korean peninsula, the activities of volcano increase continuously. For example, the volcanic eruption of Mt. Sakurajima is an example, and Mt. Baekdu can be another example potentially. In these regards, developing unified system including realtime prediction and 3D visualization of volcano ash are important to prepare the volcanic disaster systematically. In this technical report, an interactive simulator embedding dispersion algorithm and 3D visualization engine is developed. This system can contribute to the realtime prediction of volcanic disaster scientifically.

TCP 세션을 활용한 사설망 구간 CCTV 단말의 생사판별 알고리즘 (Device Alive Check Algorithm using TCP Session under CCTV Network based on NAT)

  • 신해준;정연기
    • 한국멀티미디어학회논문지
    • /
    • 제18권5호
    • /
    • pp.631-640
    • /
    • 2015
  • Recently CCTV system is installed widely purpose to enhanced physical security, gathering criminal evidence and management of facilities. In spite of supporting strong management function, CCTV system has weak security function. Therefore high security management function is required. Generally it's not easy to control the devices under NAT using a NMS(Network Management System). So we design and implement alive check algorithm of CCTV devices under NAT using DVRNS address resolution and TCP session check. We evaluated and analyzed of developed system on real environment which includes about 100 DVRs under NAT. As a result of test, it showed that device alive check and DVRNS address resolution were well performed without any error.

A Fatal Case of Acute Respiratory Failure Caused by Mycobacterium massiliense

  • Choi, Kyoung Hwa;Yu, Hae Min;Jeong, Jae Seok;Kim, So Ri;Lee, Yong Chul
    • Tuberculosis and Respiratory Diseases
    • /
    • 제74권2호
    • /
    • pp.79-81
    • /
    • 2013
  • Few recent reports have indicated that Mycobacterium massiliense causes various infections including respiratory infection. However, there is scarce information on the clinical significance, natural history of the infection, and therapeutic strategy. This report describes a case of an immunocompetent old man infected by M. massiliense that causes acute respiratory failure. In light of the general courses of non-tuberculous mycobacterium infections, rapid progression and fatality are very rare and odd. In addition, we discuss the biological and pathological properties of M. massiliense with the review of cases reported previously including our fatal one.

The Study of CFAR(Constant False Alarm Rate) process for a helicopter mounted millimeter wave radar system

  • Kim In Kyu;Moon Sang Man;Kim Hyoun Kyoung;Lee Sang Jong;Kim Tae Sik;Lee Hae Chang
    • 대한전자공학회:학술대회논문집
    • /
    • 대한전자공학회 2004년도 학술대회지
    • /
    • pp.890-895
    • /
    • 2004
  • This paper describes constant alarm rates process of millimeter wave radar that exits on non-stationary target detection schemes in the ground clutter conditions. The comparison of various CFAR processes such as CA(Cell-Average)-CFAR, GO(Greatest Of)/SO(Smallest Of)-CFAR and OS(Order Statistics)-CFAR performance are applied. Using matlab software, we show the performance and loss between detection probability and signal to noise ratio. When rang bins increase, this results show the OS-CFAR process performance is better than any others and satisfies the optimal detection probability without loss of detection in the homogeneous clutter.

  • PDF

갑상설관 낭종에서 발생한 유두상 선암 1예 (A Case of Papillary Thyroid Carcinoma Arising in Thyroglossal Duct Cyst)

  • 이경근;안해선;이광만
    • 대한두경부종양학회지
    • /
    • 제16권1호
    • /
    • pp.83-86
    • /
    • 2000
  • Thyroglossal duct cyst is common midline mass, which is related to hyoid bone and may show signs of inflammation. Carcinoma arising in the thyroglossal duct cyst is rare, occuring in less than 1% of thyroglossal duct cyst. Papillary adenocarcinoma is the most common histologic type(75-85%). The initial treatement of choice is wide excision of the tumor bearing tissue(Sistrunk procedure), resection of associated lymph node alone is enough when they are small and isolated, but a modified neck dissection must be done if regional involvement is more extensive. Its prognosis is excellent(the incidence of regional lymph node metastasis is 7% compare to 89% for papillary cancer of thyroid gland proper).

  • PDF

Standardization of South Korean Propolis

  • Woo, Soon-Ok;Lee, Kwang-Gill;Yeo, Jee-Hong;Kweon, Hae-Yong;Lee, Myoung-Lyeol;Lee, Man-Young
    • 한국잠사학회:학술대회논문집
    • /
    • 한국잠사학회 2003년도 International Symposium of Silkworm/Insect Biotechnology and Annual Meeting of Korea Society of Sericultural Science
    • /
    • pp.126-127
    • /
    • 2003
  • This study was investigated total flavonoid and phenolic contents, heavy metals, et al. fer standardization on the south Korean propolis. The propolis collected from the whole part of South Korea, such as central, southern and Jeju island. (omitted)

  • PDF