• Korean Journal of Occupational Health Nursing
• /
• v.20 no.3
• /
• pp.279-288
• /
• 2011

Purpose: The purpose of this study was to identify the relationship between occupational stress and depression of construction workers. Methods: The subjects were 168 construction workers selected from I city and K city in Korea by convenient sampling. The data were collected by self-report questionnaires from August 1 to 31, 2011. The data were analyzed by frequencies, t-test, ANOVA, Tukey test, Pearson correlation coefficient, stepwise multiple linear regression with the SPSS/WIN 15.0 program. Results: The total mean scores of occupational stress on the subjects were 46.65 and lower (below 50%) than those of the Korean male workers, standard. According to the CES-D cut-off point, the prevalence of depression was 25%. The study showed that occupational stress is positively correlated with depression. Conclusion: This study concludes that it is necessary to develop stress management program to reduce occupational stress and depression.

• Journal of Microbiology and Biotechnology
• /
• v.16 no.4
• /
• pp.505-510
• /
• 2006

A gallocyanine-bound nanoporous titanium dioxide electrode system was investigated to carry out a mediated enzyme reaction. Gallocyanine was bound either directly or through an aminopropylsilane linker to the film of nanoporous titanium dioxide and used as a mediator for nitrate reductase in the mediated enzymatic nitrate reduction. The electrode with the aminopropylsilane linker showed 20% higher efficiency of electron transfer at the same potential than that directly linked. The prepared electrodes showed $0.26{\mu}mol/h$ nitrate reduction at a $100mm^2$ surface of the electrode, and linear current response on nitrate ion concentration up to 1.0 mM, which is very useful as a biosensor of nitrate ion in water.

• Nuclear Medicine and Molecular Imaging
• /
• v.41 no.2
• /
• pp.78-84
• /
• 2007

Quantitative analysis of dynamic brain PET data using a tracer kinetic modeling has played important roles in the investigation of functional and molecular basis of various brain diseases. Parametric imaging of the kinetic parameters (voxel-wise representation of the estimated parameters) has several advantages over the conventional approaches using region of interest (ROI). Therefore, several strategies have been suggested to generate the parametric images with a minimal bias and variability in the parameter estimation. In this paper, we will review the several approaches for parametric imaging with linearized methods which include graphical analysis and mulilinear regression analysis.

• 연구논문집
• /
• s.22
• /
• pp.65-74
• /
• 1992

This paper aims at calculating optimum design dimensions to minimize the weight satisfied strain and stress intensity of the frame while loading maximum weight into a mechanical press in the static condition. Analysis of the frame was carried out by using the FEM, then the optimum condition was obtained by using these data. As modeling in the finite element analysis has great impact on the reliablity of analysis results, the analyzed object was selected a 150-ton mechanical press of J Company, the part little affected to structural rigidity was simplified, the load condition was considered in the only maximum load, the boundary condition was used by giving symmetric displacement due to symmetric boundary condition, the finite element was applied a linear membrane element. An intermediate processor program applied the normal ANSYS to analyze finite elements was developed, and the design sensitivity was calculated. This program was applied to the optimum design.

• International Journal of Air-Conditioning and Refrigeration
• /
• v.12 no.3
• /
• pp.113-122
• /
• 2004

In case of heat exchangers operating under frosting condition, the thermal resistance and the air-side pressure loss increase with a growth of frost layer. In this paper, a transient characteristic prediction model of the heat transfer for a multi-inverter heat pump with frosting on its surface was presented by taking into account the change of the fin efficiency due to the growth of the frost layer. This dynamic simulation program was developed for a basic air conditioning system composed of an evaporator, a condenser, a compressor, a linear electronic expansion valve, and a bypass circuit. The theoretical model was derived from measured heat transfer and mass transfer coefficients. We also considered that the heat transfer performance was only affected by the decrease of wind flow area. The calculated results were compared with the experimental results for frosting conditions.

• Animal Systematics, Evolution and Diversity
• /
• v.36 no.4
• /
• pp.296-303
• /
• 2020

Three species of the genus Dohrniphora, viz., D. cornuta, D. malaysiae, and D. prescherweberae were newly recorded from Korea. These newly recorded species can be easily identified by the characteristic that inner face of male hind femur equipped with a group of peg-like stout setae on basal sensory area. Peg-like setae are arranged perpendicularly in D. cornuta whereas linear in D. malaysiae and somewhat arched in D. prescherweberae. Also, concave area near the peg-like setae is also well developed in male which is smooth in D. cornuta, on the other hand, there is well developed distal carina in D. malaysiae and with groups of microtrichia in D. prescherweberae. In this study, detailed descriptions with photographs of three newly recorded species and a key to males of all Korean Dohrniphora species are provided.

• Korean Journal of Hydrosciences
• /
• v.6
• /
• pp.107-118
• /
• 1995

The water distribution system problem consists of finding a minimum cost system design subject to hydraulic and operation constraints. The design of new branchin network in a paddy irrigation system is presented here. The program based on the linear programming formulation is aimed at finding the optimal economical combination of two main factors : the capital cost of pipe network and the energy cost. Two loading conditions and booster pumps for design of pipe network are considered to obtain the least cost design.

• Proceedings of the Korean Society for Technology of Plasticity Conference
• /
• 1994.10a
• /
• pp.157-164
• /
• 1994

Finite element analysis of material deformation is successfully utilized to understand metal forming processes such as forging, extrusion and deep drawing. However, such analysis involves contact problems; a free node touches a die surface and a contact node slips along the die surface. In the present investigation, appropriate contact algorithms were developed assuming that a three dimensional surface can be divided into bilinear patches and that nodal velocities are linear during an incremental time. The algorithms were coded into a computer program and tested for a simple surface. Comparison of the test result with that obtained from a commercial code is presented and discussed.

• Proceedings of the KIEE Conference
• /
• 2001.05a
• /
• pp.20-23
• /
• 2001

Stability aspects have often been incorporated in the dispatch/pricing procedure using trial and error methods, or approximated in the dispatch optimization directly as a set of linear constraints on generation/transmission. This paper presents introduction of PSS/OPF and voltage instability analysis using the program. Additional advantages offered by FSS/OPF are easier procedures, less computation and avoidance of engineering judgement in identifying the amount of shunt requrement at the candidate buses.

• 제어로봇시스템학회:학술대회논문집
• /
• 2002.10a
• /
• pp.57.3-57
• /
• 2002

1. Introduction 2. General flux balance model 3. MetaFluxNet 3.1 Overview of MetaFluxNet 3.2 Project file format 3.3 Construction of metabolite reaction model 3.4 Metabolic flux analysis using linear programming 3.5 Visualization of MFA results 4. Conclusion and plan 5. Acknowledgement. References.