• Title/Summary/Keyword: dynamic factor

Search Result 2,069, Processing Time 0.027 seconds

Development of Structural Equation Model for Causal Relationships Among the Risk Factors of Arteriosclerosis (동맥경화증 위험요인들간의 인과관계에 대한 구조모형 구축)

  • 오현수;서화숙
    • Journal of Korean Academy of Nursing
    • /
    • v.29 no.6
    • /
    • pp.1192-1207
    • /
    • 1999
  • The purpose of this study was to clarify the dynamic relationships among risk factors of arteriosclerosis and to develop and examine a model which could explain this relationship clearly. Data were collected from medical records of 400 male clients who visited a university hospital located in Inchon for physical examinations, from May 1996 to December 1996. Data were analyzed using the LISREL (Linear Structural Relationship) 8 program. To test the fitness of the hypothesized model, chi-square, RMSR (root mean square residual), GFI (goodness of fit index), CN (critical number) and Q-plot were used. Most of the fitness measurements, except the chi-square showed that the hypothesized model complimented the real data. According to the results, there were trends that obesity and hyperlipidemia were prevalent in heavier smokers, higher alcohol intakers, and groups who excercised less. Also, hypertension was more prevalent in older age, higher alcohol intaker, and higher serum lipid level groups. In contrast to the hypothesis, alcohol intake did not significantly affect serum lipid levels. This might be due to the serum lipid measurements (total cholesterol and trigryceride) used in this study to estimate hyperlipidemia. The direct effect of smoking on hypertension was not significant. However, the total effect of smoking on the hypertension was significant since indirect effects of smoking on hypertension, such as obesity and hyperlipidemia, were significant. The total effect of obesity on hypertension was significant since the indirect effect of obesity on hypertension via hyperlipidemia was significant, although the direct effect of smoking on hypertension was not significant. The degree of explaining hyperlipidemia with smoking, exercise, and obesity was high (60%), however, the degree of explaining obesity with age, smoking, alcohol intake, and exercise was very low (7%). On the basis of these results, high risk factors of arteriosclerosis such as hypertension, hyperlipidemia, or obesity are either directly or indirectly correlated each other. Therefore, it is difficult to predict outcomes for increasing or decreasing the risk factors by simply modulating a factor. Smoking, alcohol, and exercise both directly and indirectly affected major risk factors of arteriosclerosis. Therefore, correcting these variables is required to decrease risk factors. Finally, the relationship among other risk factors which have been known to be related with arteriosclerosis (diet, stress or hereditary) should be clarified in further studies.

  • PDF

Platform Design for Optimal Migration Cost of Mobile Agents (이동 에이전트의 최적 이주 비용을 위한 플랫폼 설계)

  • 김완성;복경수;신재룡;유재수
    • Journal of the Korea Institute of Information and Communication Engineering
    • /
    • v.8 no.1
    • /
    • pp.137-149
    • /
    • 2004
  • A new software paradigm is required on the development of network and various service requirements. With this, many studies on a mobile agent have been made. For the execution of the mobile agent, migration is the most important factor that influences the performance of the mobile agent. In this paper we propose the method that leads to high migration efficiency in order to improve the performance. The features of our migration technique are as follows. First, the migration technique creates the dynamic itinerary that appropriately copes with the network conditions and the platform changes to improve the agent execution efficiency. Second, it perfecters an executed code to reduce the amount of the mobile data and reduces the execution time by instantiating the agent in advance. Third, it improves the execution efficiency by using the checkpoint-based recovery method that does not execute the agent again and recovers the process states even though the errors take place. Though the simulation we compare the proposed method with the existing methods. The simulation result shows that the proposed method outperform the existing methods in terms of migration.

Design and Implementation of Sensibilities Lighting LED Controller for a Ship (선박용 감성조명 LED 제어기의 설계 및 구현)

  • Lee, Jae-Hong;Park, Ju-Won;Lim, Jin-Kang;Lee, Sang-Bae
    • Journal of Navigation and Port Research
    • /
    • v.34 no.10
    • /
    • pp.763-768
    • /
    • 2010
  • Today the light of mankind since the dawn of mankind and that they were living "lives" on the huge influence across space is a dynamic energy. Because of this, when all human beings with the light and you can feel more comfortable with a stable mind to the beauty and the pursuit of happiness is to have instincts. In this paper, a fuzzy control system using a combination of external environmental factors, respectively, the conversion of quantitative uncertainty information into the LED lighting is designed to express algorithms, available in indoor circadian control circuit was designed and fabricated LED. Factor in the external environment temperature, humidity, and light intensity values to the controller through the sensor to accept these values and the optimal values for lighting the fuzzy control algorithm is converted into human emotion to feel comfortable to express through the dimming control LED lighting.

An Implementation of Network Intrusion Detection Engines on Network Processors (네트워크 프로세서 기반 고성능 네트워크 침입 탐지 엔진에 관한 연구)

  • Cho, Hye-Young;Kim, Dae-Young
    • Journal of KIISE:Information Networking
    • /
    • v.33 no.2
    • /
    • pp.113-130
    • /
    • 2006
  • Recently with the explosive growth of Internet applications, the attacks of hackers on network are increasing rapidly and becoming more seriously. Thus information security is emerging as a critical factor in designing a network system and much attention is paid to Network Intrusion Detection System (NIDS), which detects hackers' attacks on network and handles them properly However, the performance of current intrusion detection system cannot catch the increasing rate of the Internet speed because most of the NIDSs are implemented by software. In this paper, we propose a new high performance network intrusion using Network Processor. To achieve fast packet processing and dynamic adaptation of intrusion patterns that are continuously added, a new high performance network intrusion detection system using Intel's network processor, IXP1200, is proposed. Unlike traditional intrusion detection engines, which have been implemented by either software or hardware so far, we design an optimized architecture and algorithms, exploiting the features of network processor. In addition, for more efficient detection engine scheduling, we proposed task allocation methods on multi-processing processors. Through implementation and performance evaluation, we show the proprieties of the proposed approach.

A Parametric Image Enhancement Technique for Contrast-Enhanced Ultrasonography (조영증강 의료 초음파 진단에서 파라미터 영상의 개선 기법)

  • Kim, Ho Joon;Gwak, Seong Hoon
    • KIPS Transactions on Software and Data Engineering
    • /
    • v.3 no.6
    • /
    • pp.231-236
    • /
    • 2014
  • The transit time of contrast agents and the parameters of time-intensity curves in ultrasonography are important factors to diagnose various diseases of a digestive organ. We have implemented an automatic parametric imaging method to overcome the difficulty of the diagnosis by naked eyes. However, the micro-bubble noise and the respiratory motions may degrade the reliability of the parameter images. In this paper, we introduce an optimization technique based on MRF(Markov Random Field) model to enhance the quality of the parameter images, and present an image tracking algorithm to compensate the image distortion by respiratory motions. A method to extract the respiration periods from the ultrasound image sequence has been developed. We have implemented the ROI(Region of Interest) tracking algorithm using the dynamic weights and a momentum factor based on these periods. An energy function is defined for the Gibbs sampler of the image enhancement method. Through the experiments using the data to diagnose liver lesions, we have shown that the proposed method improves the quality of the parametric images.

A Service Selection Method using Trust Evaluation in QoS based Web Services Composition (QoS 기반 웹서비스 조합에서 신뢰성 평가를 통한 서비스 선택 기법)

  • Kim, Yu-Kyong;Ko, Byung-Sun
    • Journal of KIISE:Software and Applications
    • /
    • v.36 no.1
    • /
    • pp.1-9
    • /
    • 2009
  • In heterogeneous and distributed computing environments, with an increasing number of Web services providing similar functionalities, the reliability of Web services is a critical decision factor. To fulfill the open business model such as cooperation among enterprises, several Web services can be composed into the upper level business transaction. In Web services composition, the reliability of services is more and more critical. Though each unit Web service can be reliable, the reliability of the composed service is not guaranteed. Thus a way to efficiently assess and select composed Web services is needed. In this paper, we define new metrics for measuring the trust value of Web services, and propose an evaluation method to predict the trustworthy degree of the composed services based on the metrics. We also define a conceptual framework to support optimal Web services selection based on the proposed trust evaluation method. By selecting using the quantitative measurement rather than intuitive selection of the service user, it allows the service users to select the high reliable service meeting their quality requirements well.

Effects of Rotarod Exercise and Electroacupuncture on Muscle Activity and Serum BDNF Level in the Ataxic Rats by the 3-Acetylpyridine (3-Acetylpyridine에 의한 운동실조 동물모델에서 로타로드 운동과 전침이 근활성도와 혈청 BDNF에 미치는 영향)

  • Rho, Min-Hee;Park, Sook-Young
    • The Journal of the Korea Contents Association
    • /
    • v.10 no.4
    • /
    • pp.236-246
    • /
    • 2010
  • The 3-Acetylpyridine(3-AP) induces cerebellar injury which is chemoablation of the inferior olive nucleus. The purpose of this study was to investigate the effects of exercise(Ex) and electroacupuncture(EA) on muscle activity of hindlimb and serum brain derived neurotrophic factor(BDNF) in the ataxia rats by the 3-AP. 12-week-aged male Sprague-Dawley rats were randomly divided into the 5 groups: Control, 3-AP, 3-AP+Ex, 3-AP+EA and 3-AP+Ex+EA groups. Maximal Height Vertical Jump(MHVJ) was significantly decreased in the 3-AP compared with control group, and it was increased in Ex, EA and Ex+EA groups than 3-AP group. The muscle activity of hindlimb was significantly increased in the 3-AP groups than control group, also it was most decreased in Ex+EA group. The concentration of BDNF of the serum was significantly decreased in the Ex, EA and Ex+EA groups than 3-AP group. The results of this study showed that dynamic exercise and electroacupuncture have a positive effect on functional recovery and in the ataxia rats by the 3-AP.

URBAN ENVIRONMENTAL QUALITY ANALYSIS USING LANDSAT IMAGES OVER SEOUL, KOREA

  • Lee, Kwon-H.;Wong, Man-Sing;Kim, Gwan-C.;Kim, Young-J.;Nichol, Janet
    • Proceedings of the KSRS Conference
    • /
    • 2007.10a
    • /
    • pp.556-559
    • /
    • 2007
  • The Urban Environmental Quality (UEQ) indicates a complex and various parameters resulting from both human and natural factors in an urban area. Vegetation, climate, air quality, and the urban infrastructure may interact to produce effects in an urban area. There are relationships among air pollution, vegetation, and degrading environmental the urban heat island (UHI) effect. This study investigates the application of multi-spectral remote sensing data from the Landsat ETM and TM sensors for the mapping of air quality and UHI intensity in Seoul from 2000 to 2006 in fine resolution (30m) using the emissivity-fusion method. The Haze Optimized Transform (HOT) correction approach has been adopted for atmospheric correction on all bands except thermal band. The general UHI values (${\Delta}(T_{urban}-T_{rural})$) are 8.45 (2000), 9.14 (2001), 8.61 (2002), and $8.41^{\circ}C$ (2006), respectively. Although the UHI values are similar during these years, the spatial coverage of "hot" surface temperature (>$24^{\circ}C$) significantly increased from 2000 to 2006 due to the rapid urban development. Furthermore, high correlations between vegetation index and land surface temperature were achieved with a correlation coefficients of 0.85 (2000), 0.81 (2001), 0.84(2002), and 0.89 (2006), respectively. Air quality is shown to be an important factor in the spatial variation of UEQ. Based on the quantifiable fine resolution satellite image parameters, UEQ can promote the understanding of the complex and dynamic factors controlling urban environment.

  • PDF

Simple Camera-based Evaluation System for Lower Limb Alignment during Pedalling (자전거 페달링 시 하지 정렬 평가를 위한 영상 시스템 개발)

  • Oh, Ho-Sang;Choi, Jin-Seung;Kang, Dong-Won;Seo, Jeong-Woo;Bae, Jae-Hyuk;Tack, Gye-Rae
    • Korean Journal of Applied Biomechanics
    • /
    • v.22 no.1
    • /
    • pp.123-129
    • /
    • 2012
  • Simple camera-based system for evaluation of lower limb alignment as a part of an automated cycling fitting system was developed and verified in this study. Developed imaging system can evaluate lower limb alignment quantitatively during pedaling using a general camcorder and single marker attached on the knee. Threshold-based marker detection algorithm was proposed in this study. Experiment was carried out to compare the trajectory data from marker detection algorithm of the developed imaging system with the trajectory data from 3-D motion capture system. Results showed that average error between trajectories was 2.33 mm (0.92 %) in the vertical direction and 0.62 mm (1.86 %) in the medio-lateral direction. There existed significant correlation between two measured values (r=0.9996 in the vertical direction and r=0.9975 in the medio-lateral direction). It can be concluded that developed imaging system be applied to evaluate lower limb alignment which is an important factor for dynamic bicycle fitting.

Friction Power Loss Reduction for a Marine Diesel Engine Piston (박용엔진 피스톤 스커트 프로파일 변경에 의한 마찰손실(FMEP) 저감 연구)

  • An, Sung Chan;Lee, Sang Don;Son, Jung Ho;Cho, Yong Joo
    • Tribology and Lubricants
    • /
    • v.32 no.4
    • /
    • pp.132-139
    • /
    • 2016
  • The piston of a marine diesel engine works under severe conditions, including a combustion pressure of over 180 bar, high thermal load, and high speed. Therefore, the analyses of the fatigue strength, thermal load, clamping (bolting) system and lubrication performance are important in achieving a robust piston design. Designing the surface profile and the skirt ovality carefully is important to prevent severe wear and reduce frictional loss for engine efficiency. This study performs flexible multi-body dynamic and elasto-hydrodynamic (EHD) analyses using AVL/EXCITE/PU are performed to evaluate tribological characteristics. The numerical techniques employed to perform the EHD analysis are as follows: (1) averaged Reynolds equation considering the surface roughness; (2) Greenwood_Tripp model considering the solid_to_solid contact using the statistical values of the summit roughness; and (3) flow factor considering the surface topology. This study also compares two cases of skirt shapes with minimum oil film thickness, peak oil film pressure, asperity contact pressure, wear rate using the Archard model and friction power loss (i.e., frictional loss mean effective pressure (FMEP)). Accordingly, the study compares the calculated wear pattern with the field test result of the piston operating for 12,000h to verify the quantitative integrity of the numerical analysis. The results show that the selected profile and the piston skirt ovality reduce friction power loss and peak oil film pressure by 7% and 57%, respectively. They also increase the minimum oil film thickness by 34%.