• Journal of Advanced Marine Engineering and Technology
• /
• 제17권4호
• /
• pp.87-99
• /
• 1993

Nowadays, the cartridge valve can be controlled proportionally in remote place by adopting proportional solenoid and it becomes widely used as control component in hydraulic systems. Especially, multi stage proportional valve is attractive because it consumes less input power though its characteristics might slightly be defected. But, the system parameter should be carefully chosen to obtain optimistic characteristics. This study concerning three stage proportional throttle control valve is purposed to examine the influences of paameters to the dynamic characteristics. The typical transient and frequency responses of proportional throttle control valve were inspected through the experiments and compared to those derived from the theoritical analyses. And it was confirmed that the analyses are appropriate. Then the influences of various system parameters to the dynamic characteristics were examined by means of simulations. For the analyses, the basic equations derived from lumped model were linearized and the linearized equations were transformed to the transfer functions between inputs and outputs. Then the transient responses and frequency responses were obtained from transfer functions. 1. It is appropriate to estimate the dynamic characteristics of valve which has relatively sophisticated structure by means of system analyses using linearized equations. 2. Though the valve has two pilot stages, fairly good characteristics can be obtained by carefully choosing system parameters. 3. Main valve very quickly follows the movement of second pilot valve when the parameters of main valve(the oil supply passage and discharge passage fpr second pilot valve) are appropriately chosen.

• 한국정밀공학회지
• /
• 제22권8호
• /
• pp.92-99
• /
• 2005

Tungsten heavy metal is characterized by a high density and novel combination of strength and ductility. Among them, 90W-7Ni-3Fe is used for applications, where the high specific weight of the material plays an important role. They are used as counterweights, rotating inertia members, as well as fur defense purposes(kinetic energy Penetrators, etc.). Because of these applications, it is essential to detemine the dynamic characteristics of tungsten alloy. In this paper, Explicit FEM(finite element method) is employed to investigate the dynamic characteristics of tungsten heavy metal under base of stress wave propagation theory for SHPB, and the model of specimen is divided into two parts to understand the phenomenon that stress wave penetrates through each tungsten base and matrix. This simulation results were compared to experimental one and through this program, the dynamic stress-strain curve of tungsten heavy metal can be obtained using quasi static stress-strain curve of pure tungsten and matrix.

• 대한교통학회지
• /
• 제20권6호
• /
• pp.99-113
• /
• 2002

교통량배분문제 가운데 다중계층 교통량배분문제는 유일해가 보장되지 않는 대표적 사례로 최근 들어 모형의 정식화 및 해법에 관해서 활발하게 전개되고 있다. 정식화에 있어서는 변동부등식이나 고정점 문제를 활용한 정식화가 보편적으로 활용되고 있으나 해법(알고리즘)에 관한 연구는 미흡한 실정이다. 본 연구에서는 변동부등식으로 정의된 다중계층 이용자균형 교통량배분문제의 해법으로서 GA알고리즘과 대각화알고리즘, 군집화알고리즘을 조합한 Hybrid Algorithm을 개발, 제안한다. GA알고리즘과 군집화알고리즘은 해의 탐색을 전역적이면서도 효과적으로 수행하기 위해서 도입된 대각화 알고리즘의 보완적 알고리즘이라 할 수 있다. 본 연구에서는 또한, 다중계층 이용자균형 교통량배분문제의 해법으로서의 제안된 AMSA(The Algorithm of Multiclass Static User Equilibrium Assignment)의 특징을 예제풀이를 통해서 설명하고 있다.

• 센서학회지
• /
• 제14권4호
• /
• pp.250-257
• /
• 2005

Respiratory tubes with the length of 35 mm and the diameter of 10, 15, and 20 mm were made and both the static($P_{S}$) and dynamic($P_{D}$) pressures were measured for steady flow rates ranging 1-12 l/sec. Regression analysis resulted successful fitting of $P_{S}$ and $P_{D}$ data with quadratic equations with correlation coefficients higher than 0.99. The measurement standards of the American Thoracic Society (ATS) were applied to $P_{S}$ data, which demonstrated the smallest tube diameter of 15 mm to satisfy the ATS standards. The maximum $P_{D}$ value of the velocity type transducer with the diameter of 15 mm was estimated to be 75 cm$H_{2}O$, implying approximately 7 times larger sensitivity than the widely used pneumotachometer. These results showed that the velocity type respiratory air flow transducer is a unique device accomplishing miniaturization with the sensitivity increased, thus would be of great advantage to develop portable devices.

• 한국측량학회:학술대회논문집
• /
• 한국측량학회 2004년도 추계학술발표회 논문집
• /
• pp.99-104
• /
• 2004

Recently, the old surveying method for acquiring surveying-geo information results had a low economic efficiency and a low dependence of precision because it took much times and high costs. So, we acquired law data by execution of control surveying through Static positioning of DGPS(Ashtech). It is computed plainmetric(X, Y) positioning through postprocessing by Prism S/W. And we computed height(Z) through control surveying by ring-closed leveling surveying. After control surveying execution, we built DEM(Digital Elevation Model) using LDT S/W and accuracy 3D detail surveying by EDM(Electronic Distance Measurement) surveying. The purpose of this study was to yield automated digital mapping and the automated amount of materials using ahead data. The conclusions were as follows; First, we built the automated amount of materials system and got high efficiency about personnel, times and precision. Second, when, people precisely positioned on railroads of a high-speed railroad and used GPS surveying, the result was permitted. Finally, it was possible to draw automated profile and cross-section using the 3D terrain model build with the DEM technique.

• 대한의용생체공학회:의공학회지
• /
• 제26권3호
• /
• pp.163-169
• /
• 2005

Respiratory tubes with a length of 35mm and diameters of 10, 15, and 20mm were made for experimental purpose, and both the static$(P_s)\;and\;dynamic(P_D)$ pressures were simultaneously measured for steady flow rates ranging 1-12//sec. Least squares analysis resulted successful fitting of $P_s\;and\;P_D$ data with quadratic equations with correlation coefficients higher than 0.99(P<0.0001). The spirometric measurement standards of the American Thoracic Society(ATS) were applied to $P_s$ data, which demonstrated the smallest tube diameter of 15mm to satisfy the ATS standards. The maximum $P_D$ value of the velocity type transducer(the functional single use respiratory air flow tube) with the diameter of 15mm was estimated to be approximately $75cmH_2O$, implying more than 7 times larger sensitivity than the widely used pneumotachometers. These results showed that the velocity type respiratory air flow transducer is a unique device accomplishing miniaturization with the sensitivity increased, thus would be of great advantage to develop portable medical devices.

• 한국통신학회논문지
• /
• 제36권2A호
• /
• pp.91-99
• /
• 2011

이동 통신 시스템에서 음영 지역의 셀 커버리지를 확보하기 위하여 다양한 종류의 중계기가 사용되고 있다. 그러나 일반적인 무선 중계기는 송 수신 안테나 간의 궤환신호로 인한 발진 문제 때문에 고출력 옥외 중계기로 상용하기 어렵다. 궤환 간섭제거 중계기는 디지털 적응필터를 이용하여 송 수신 안테나 간의 궤환신호를 제거하여 발진을 방지한다. 본 논문에서는 dual NLMS(Normalized Least Mean Square) 알고리듬을 제안하며, 궤환 채널의 도플러 주파수 추정을 통하여 적응필터의 스텝 사이즈를 결정한다. 시불변 채널 및 다중 경로 페이딩 채널 환경에서 제안하는 알고리듬의 성능을 분석하고 모의 실험을 통하여 검증한다.

• 한방재활의학과학회지
• /
• 제20권2호
• /
• pp.89-99
• /
• 2010

Objectives : This study was designed to analyze the pattern of asymmetrical alignment. Methods : This study was carried out with the data from comprehensive medical testing. 91 subjects aged 30-39 were evaluated by full spine AP X-ray. For pelvis, innominate measurement(IM), off centering measurement(OCM), ilium shadow measurement(ISM), major axis of obturator foramen(MaF), minor axis of obturator foramen(MiF) were analyzed. Spinal curvature and height of shoulder girdle were analyzed. Results : 1. In pelvis, It. posterior-inferior and it. inflare combination pattern was 38 cases(42.8%). 2. In spinal curvature, "reverse S" curve was 45 cases(49.4%) and "reverse C" curve was 30 cases(33%). 3. In shoulder girdle, It. superior pattern was 42 cases(46.1 %) and It. superior pattern was 39 cases(42.9%). 4. In whole body analysis, It. posterior-inferior and It. inflare pelvis, "reverse S" spinal curvature and It. superior shoulder girdle combination patten was 11 cases(12.1 %). This pattern is similar to Kendall's right handedness pattern and Zink's common compensatory pattern. Conclusions : Results from this investigation showed asymmetrical alignment in 30-39 years-old adults. This results are expected to contribute to classifying the alignment pattern in clinic and systemic treatment.

• Bulletin of the Korean Chemical Society
• /
• 제27권1호
• /
• pp.99-105
• /
• 2006

Polyamine dendrimers functionalized with electrochemiluminescent (ECL) polypyridyl Ru(II) complexes, dend-$[CO-(CH_2)_3-mbpy{\cdot}Ru(L)_2]_3(PF_6)_6$ (dend: N$(CH_2CH_2NH)_3$-, L: bpy, o-phen, phen-Cl, DTDP), were synthesized through the complexation of dendritic polypyridyl ligands to Ru(II) complexes. Their electrochemical redox potentials, photoluminescence (PL), and relative ECL intensities were studied. The ECL emissions produced by the reaction between the electro-oxidized $Ru^{3+}$ species of polyamine dendrimers and tripropylamine as a coreactant were measured in a static system with potential cycles between 0.8 and 1.3 V or through flow injection analysis with a potential of +1.3 V, and were compared to that of $[Ru(o-phen)_3](PF_6)_2{\cdot}Dend-[CO-(CH_2)_3-mbpy{\cdot}Ru(bpy)_2]_3(PF_6)_6$ showed an ECL intensity that was two-fold greater than that of the reference complex $[Ru(o-phen)_3](PF_6)_2$.

• 패션비즈니스
• /
• 제9권5호
• /
• pp.1-14
• /
• 2005

The purpose of this study was to analysis the perception of men's wear brands (Intermezzo and Rogatis), for developing the possibility & strategy of the nichi-market in men's wear market for the apparel marketers and manufactures. For this study, the data obtained from 312 respondents were analyzed by descriptive statistics, ANOVA. The results from the study were as follow ; The perception of the 2 brand images revealed that Intermezzo accounted for 79.8% of the frequencies, and Rogatis accounted for 99%. Also, results revealed the total evaluation of Intermezzo accounted for 3.86 of the mean rated on 5 point Likert-type scales in the 9 features, and Rogatis accounted for 3.28. And then, results revealed that there were signifiant differences in 2 cluster of Rogatis that the purchasing cluster accounted for 3.46 of the mean, and the perceiving cluster accounted for 3.07. The brand images of Intermezzo and Rogatis were evaluated and rated on 5 point Likert-type scales of 17 pair adjectives. As a results, the image characteristic with Intermezzo was considered with more dynamic, trendy than the image characteristic with Rogatis. Also, results revealed that The Image with Intermezzo was considered with urban, lively, chic, modern, and sophsticated image-features, and the Image with Rogatis were evaluated mannish, urban, sophsticated, luxury, and static image-features.