• Bulletin of the Korean Space Science Society
• /
• 2008.10a
• /
• pp.24.3-24.3
• /
• 2008

The signals transmitted from satellites of Global Navigation Satellite System (GNSS) interact with the plasma of the ionosphere. To study the impact of the ionospheric plasma on GNSS applications a comprehensive knowledge of the ionosphere is required. Especially the correct measurement of the ionosphere such as the peak height of the F2 layer peak electron density (hmF2) is important for the GNSS ionospheric model. Anyang ionosonde station ($37.39^{\circ}N$, $126.95^{\circ}E$) has been operating from October 2000 and the accumulated data for 8 years may allow us to obtain climatological characteristics of middle latitude ionospheric F region for GNSS application. We analyzed the variations of the hmF2 and NmF2 over Anyang station for different conditions of solar activity, geomagnetic activity, season, and local time, and we compared our results with the IRI model.

• Journal of the Korean Operations Research and Management Science Society
• /
• v.18 no.3
• /
• pp.129-149
• /
• 1993

The high level of activity in the development and maintenance of computer software makes the scheduling of software projects an importnat factor in reducing operating costs and increasing competitiveness. Software activity is labor intensive. Scheduling management of hours of software work is complicated by ther interdependencies between the segments of work, and the uncertainties of the work itself. This paper discusses issues of scheduling in software engineering management, and presents a modular decomposition model for software project scheduling, taking advantage of the facility for decomposition of a software project into relatively independent work segment modules. Modular decomposition makes it possible to treat scheduling as clustering and sequencing in the context of integer programming. A heuristic algorithm for the model is presented with some computational experiments.

• Journal of Hydrogen and New Energy
• /
• v.31 no.5
• /
• pp.444-452
• /
• 2020

This study investigated the cathode catalyst of direct borohydride/hydrogen peroxide fuel cells for space exploration. Various catalysts such as Au, Ag, and Ni were supported on multiwalled carbon nanotubes (MWCNTs). Various techniques, such as transmission electron microscopy, Brunauer-Emmett-Teller method, scanning electron microscopy, and X-ray diffraction were conducted to investigate the characteristics of the catalysts. Fuel cell tests were performed to evaluate the performance of the catalysts. Ag/MWCNTs exhibited better catalytic activity than the Ni/MWCNTs and better catalytic selectivity of the Au/MWCNTs. Ag/MWCNTs presented good catalytic activity and selectivity even at an elevated operating temperature. The performance of Ag/MWCNTs was also stable for up to 60 minutes.

• Journal of the Korea Institute of Military Science and Technology
• /
• v.3 no.2
• /
• pp.156-165
• /
• 2000

This paper describes modeling and simulation of automotive forward collision warning and avoidance system using CASE(Computer-Aided Systems Engineering) tool. The system is composed or many sensors, a controller, warning devices, brakes and etc. The system was modeled by one activity chart, fourteen state charts and one module chart. Rear-end collision scenarios was generated by Simulink and used to support Stalemate model. The resulting model was used to evaluate the correctness of function and behavior of the system. A simulator for the system has been designed and used to validate the model under realistic operating conditions in the laboratory. To model and simulate the system's functionality and behavior brings clarity to system design early in the system development.

• Proceedings of the KSR Conference
• /
• 2005.11a
• /
• pp.618-622
• /
• 2005

Railway safety case is an important measure for demonstrates operating company's capability, commitment and competence in accordance with Railway Regulation 2000 in UK. Safety case describes the scope of operation, definition and boundary of activity, risk analysis, system safety activity, annul safety plan. Relationships between' these components and company's policy, organization, human resource, control measure, investment plan are also included. A case study for Network Rail (infrastructure manager)'s safety case is described in this paper for the construction of safety rule and safety planning.

• Proceedings of the Korean Institute of Intelligent Systems Conference
• /
• 1993.06a
• /
• pp.1137-1140
• /
• 1993

A dynamic-structure system is one that has the flexibility to change the system configuration automatically so as to operate in an optimal manner. A conceptural model for a dynamic-structure system is presented in this paper. In this model, the interchangeable components of the overall system are grouped together. Their activity levels are evaluated by an intelligent preprocessor that is associated with the group. A knowledge-based task distribution system evaluates the activity levels and makes decisions as to how the components operating below capacity should be shared with workcells that have similar components that are overloaded. Associated decision making can be effected through fuzzy logic and particularly the compositional rule of inference. A simulation example is given to illustrate the application of dynamic structuring.

• Journal of Distribution Science
• /
• v.17 no.11
• /
• pp.81-92
• /
• 2019

Purpose: The salesperson, the core of the operating activities, plays the role of connecting the inside and outside of the company, representing the company to the consumer and identifying and responding to the customer's needs. The department store industry is the most representative retail industry in South Korea, and competition among its peer group and industry is intensifying, requiring differentiated service sales activities and performance from its employees. This study divided the sales force system into activity control(process-oriented control) and output control(performance-oriented control) and verified the differential impact on the job attitude of the salesperson (e.g., job satisfaction and burn-out), respectively. In addition, the effect of job satisfaction and burn-out of the salesperson on the job performance were checked. Research design, data, and methodology: The survey was conducted on 200 sales people working at five branch stores of Hyundai department store in Seoul, and 194 of them were analyzed. The reliability and validity of the variables were analyzed and hypotheses were verified through the SEM. Results: Results have shown that activity control has a greater impact on burn-out compared to output control, and output control has a greater impact on job satisfaction compared to activity control. It has been shown that the salesperson's burn-out does not affect sales performance, but that job satisfaction has a positive effect on sales performance. Conclusions: This study examines the effect of sales force management system such as activity control and output control, on the job attitude and sales performance in department stores. According to the results of this research, each of two control systems have a discriminatory effect on the job attitude variables. For the sales managers of department store, it is recommended to increase the efficiency of sales management by increasing the use of outcome control compared to activity control.

• Korean Journal of Community Nutrition
• /
• v.11 no.5
• /
• pp.642-649
• /
• 2006

The purposes of this study were to investigate methods of applying activity-based cost to menu engineering and to examine the feasibility. A total of 6 menu items of XYZ restaurant in Seoul were selected and the ledger of September 2005 was used for menu analysis. The menu mix percent of beef sirloin steak (61.95%) and beef tenderloin steak (17.13%) were labeled as high, whereas BBQ pork ribs (4.94%), salmon fillet (2.66%), seafood platter (5.77%), and teriyaki chicken (7.56%) showed low menu mix percent. In addition, the contribution margin for BBQ pork ribs (29,000 won), salmon fillet (25,810 won), seafood platter (22,400 won), and teriyaki chicken (22,000 won) were higher than the average contribution margin (21,957 won), and those for beef sirloin steak (21,200 won) and beef tenderloin steak (21,900 won) were lower than average. When popularity and contribution margin were applied in menu engineering, BBQ pork ribs, salmon fillet, seafood platter and teriyaki chicken were classified as puzzles and beef tenderloin steak and beef sirloin steak as plowhorses. Menu engineering using popularity and operating profit, which was calculated from activity-based cost, also gave the same results, whereas the additional label for activity cost placed BBQ pork ribs and salmon fillet in the brain teaser category. Ranking analysis on variables estimating menu profitability using Spear-man's ${\rho}$ revealed that there were no significant correlation between variables, which means the estimation of menu item profitability could differ by methods of analysis. With these results, it was concluded that activity-based cost would help to establish more detailed marketing strategy for a restaurant.

• Journal of the Korean Wood Science and Technology
• /
• v.48 no.1
• /
• pp.107-116
• /
• 2020

Termiticidal and fungicidal activities of wood vinegar from Cinnamomum parthenoxylon (CP) stem wood have been evaluated against Coptotermes curvignathus and wood rotting fungi (Schizophyllum commune and Fomitopsis palustris). The utilized CP wood vinegar was produced in the operating temperature range 250-300℃ pyrolysis. A no-choice test was applied for evaluating termiticidal activity with 33 active termites and antifungal activity using the agar media assay. The result showed that an increase in the concentrations of CP wood vinegar significantly raised the mortality of termite. CP wood vinegar showed high termiticidal activity, organic acids (acetic acid 42.91%, 3-butenoic acid 6.89%, butanoic acid, 2-propenyl ester 2.26%), and ketones (1-hydroxy-2-propanone 5.14%, 3-methylcyclopentane-1,2-dione 2.34%) might be largely contributed to termiticidal activity in addition to other minor components. Furthermore, CP wood vinegar exhibited significant inhibition of fungal growth. These data showed that CP wood vinegar was more toxic to white-rot fungi (S. commune) than brown-rot (F. palustris). The results suggested that phenolic compounds from lignin degradation were responsible for good antifungal activity.

• Journal of the Society of Disaster Information
• /
• v.18 no.3
• /
• pp.660-671
• /
• 2022

Purpose: This study is intended to confirm the business disruptive risk in the Serious Accidents, and propose a plan to comply with the Serious Accidents Punishment Act through the Disaster Mitigation Activity Management System. Method: Through literature review and case studies, the requirements and characteristics of each of the Serious Accidents Punishment Act, the Disaster Mitigation Activity Management System, and ISO 45001 were compared and analyzed, and implications were derived. Result: The business disruption and financial adverse effects caused by industrial accidents were identified. Based on this and by using the Disaster Mitigation Activity Management System, measures to link the documentation requirements of the the Serious Accidents Punishment Act to the Disaster Mitigation Activity Management System, and to manage the implementation records of the Serious Accidents Punishment Act's duty were derived. Conclusion: When establishing and operating the Disaster Mitigation Activity Management System, it can not only comply with the Serious Accidents Punishment Act but also contribute to maintaining business continuity and ESG management through the prevention of various disasters and the minimization of secondary damage, etc.