• Proceedings of the Korean Society of Agricultural Engineers Conference
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• 2000.10a
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• pp.302-307
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• 2000

The wintering honey bee chambers were constructed and inside environment factors were analyzed to provide high technology for efficient wintering of honeybee colonies. As a result of this study, inside air temperature of yongin chamber under the wide range of outside temperature condition was found to be appropriated for wintering of bee, and inside temperature of beehive was about 2$^{\circ}C$ higher than the air temperature in the chamber. The fan operation schedule did not control the high temperature down properly in the chamber, It was necessary to find a new fan operation schedule to be able to provide the optimum temperature for wintering honey bee colonies. inside humidity variation of Yongin chamber was very much depended on outside humidity.

• Proceedings of the Korea Association of Information Systems Conference
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• 2000.11a
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• pp.1.4-4
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• 2000

We present an autonomous distributed manufacturing system to plan the manufacturing process and the schedule based on a customer order, which considers the system efficiency as well as to the flexibly. In our system, an intermediate conceptual agent called process agent is introduced, of which the role is to create a plausible alternative for the working group to fulfill the given order. The process related decision such as process sequence, allocated facilities, schedule and cost is also made simultaneously. Given an order, several these process agents are created, and the optimum on is selected through a bidding mechanism. As a criterion of such a decision-making, we consider a concept of value which is determined by several factors such as cost, delivery, working ratio and so forth. Every agent consisting of the system makes decisions and actions so as to maximize its possessing value, and the overall behavior of the system is controlled by the value distribution.

• Proceedings of the KIEE Conference
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• 1987.07a
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• pp.288-292
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• 1987

The purpose of this paper is to develope the parallel computation algorithm that enables it to minimize the completion tine of computation execution of the entire subtasks, under the constraints of the series-parallel precedence relation in each subtask. The developed algorithm was applied to the control of a robot manipulator functioned by multi-CPU's and to obtain the minimum time schedule so that real time control may be achieved. The completion time of computation execution was minimized by applying "Variable" Branch and Bound algorithm which was developed In this paper in determining the optimum ordered schedule for each CPU.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.16 no.6
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• pp.112-123
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• 2017

The accurate forecasting of the public transportation's transit and arrival time has become increasingly important as more people use buses and subways instead of personal vehicles under the government's public transportation promotion policy. Using bus management system (BMS) data, which provide information on the real-time bus location, operation interval, and operation history, it is now possible to analyze the bus schedule reliability. However, the punctuality should always be considered together with the operation safety. Therefore, this study suggests a new methodology to secure both reliability and safety using the BMS data. Unlike other studies, we calculated the bus travel time between two bus stops by dividing the total travel length into 6 sections using 5 different measuring points. In addition, the optimal travel time for each bus route was proposed by analyzing the mean, standard deviation and coefficient of variation of the each section's measurement. This will ensure the reliability, safety and mobility of the bus operation.

• Journal of the Korean Institute of Navigation
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• v.5 no.1
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• pp.1-23
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• 1981

As far as transportation problems are concerned, the minimization of transportation cost is the most prevailing object. But in some cases, the cargo delivery time is the utter problem rather than the cost. For instance, we may imagine the case that the delivery of the construction materials is delayed behind the schedule and this makes the construction cost increased because of idle time of other materials and man power, in addition to the indemnity. Therefore the allocation of ships, in marine transportation which is now the main route of overseas trade, to the needed area on the required time is to be appropriately performed. However, there are several restrictions for cargo delivery to meet the demand, such as ship's size, number to be employed and cargo handling capacity of the ports, etc. And there are some other factors to be considered, that is, the degree of necessities of commodities, on their kinds, amount, and the time of arrival, etc. This paper deals with the problem of optimum allocation of ships emphasizing the cargo delivery time adopting Linear Programming technique with those cargo delivery restrictions and factors transformed by introducing the multi-speed conception, the conversion of multi-commodity to a single commodity, allowable delivery time, weight penalty number and nominating priority. This paper presents a case of optimum allocation of ships in the light of cargo delivery time for a construction company which has two different construction places and analyzes the result. This study will give a planner a good tool for optimum planning of maring transportation and be used for decision of schemes.

• Journal of the Korean Ceramic Society
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• v.28 no.6
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• pp.488-494
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• 1991

In this study, the effects of catalyst and DCCA content were investigated in order to determine the optimum conditions of monolithic silica gel formation through sol-gel process. Formamide, oxalic acid, glycerol and dimethylformamide are used as DCCA. To observe the phenomena in drying and heat-treating of gels, we examined structural exchange of gels using FT-IR, TG-DTA and XRD. Monolithic gels were obtained by adding formamide and dimethylformamide as DCCA. According to the heat treatment schedule, silica glass is prepared by heat-treatment up to 1050$^{\circ}C$.

• Journal of the Korean Ceramic Society
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• v.28 no.10
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• pp.793-802
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• 1991

The multicrystalline machinable ceramics was fabricated by melting method using domestic pyrophyllite. After determination of optimum crystallization temperature and time from results of DTA, XRD and SEM, base glasses were heat treated by 2-step schedule. Main crystalline phases identified by XRD, EDX were Na-fluorophlogopite, ${\beta}$-spoduemen and ${\alpha}$-cordierite, and the crystallization condition of these crystals was varied with chemical composition, thermal history and nucleation agents. The thermal, chemical properties of prepared samples were excellent.

• IE interfaces
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• v.16 no.spc
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• pp.132-137
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• 2003

We consider scheduling jobs on multipurpose machines where jobs can be processed by a subset of the machines operated in parallel with the objective of minimizing makespan. We apply LPT(Longest Processing Time first) algorithm and prove that its posterior worst-case performance ratio is at most $log_24m/(1+{\lambda})$, where \lambda is the number of machines eligible for processing the job with the latest completion time. In general, LPT is shown to always find a schedule with makespan at most $log_24m/3$ times optimum.

• Proceedings of the Korea Concrete Institute Conference
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• 1995.04a
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• pp.183-188
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• 1995

Up to date, high-strength concrete pile which is producing in factory sells in the market. But according to the site and the construction conditions, the system to produce high-strength concrete pile directly in site is utilized in advanced country. Such the production system is the technique phenomenon very disirable in the side of quality control in site and the construction schedule, the time and the cost saving. This study is a fundamental experiment including concrete mixing design, non-autoclave curing method and the optimum condition to produce high-strengh concrete pile in site. As results of this study, High-strength concrete pile in site which target strength is 400kg/ $\textrm{cm}^2$ is able to produce it with optimum curing ciondition(75$^{\circ}C$, 9hr)and mixing design.

• Radiation Oncology Journal
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• v.16 no.4
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• pp.357-366
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• 1998

Brachytherapy is an essential part of radiotherapy for uterine cervical cancer. The low dose rate (LDR) regimen has been the major technique of intracavitary therapy for cervical cancer. However, there has been an expansion in the last 20 years of high dose rate (HDR) machines using Ir-192 sources. Since 1979, HDR brachytherapy has been used for the treatment of uterine cervical cancer in Korea. The number of institutions employing HDR has been increasing, while the number of low dose rate system has been constant. In 1995, there was a total 27 HDR brachytherapy units installed and 1258 cases of patients with cervical cancer were treated with HDR Most common regimens of HDR brachytherapy are total dose of 30-39 Gy at point A with 10-13 fractions in three fractions per week. 24-32 Gy with 6-8 fractions in two fractions per week, and 30-35 Gy with 6-7 fractions in two fractions per week. The average fractionation regimen of HDR brachytherapy is about 8 fractions of 4.1 Gy each to Point A. In Korea, treatment results for HDR brachytherapy are comparable with the LDR series and appears to be a safe and effective alternative to LDR therapy for the treatment of cervical carcinoma. Studies from the major centers report the five-year survival rate of cervical cancer as. 78-86$\%$ for Stage 1, 68-85$\%$ for stage 11, and 38-56$\%$ for Stage III. World-wide questionnaire study and Japanese questionnaire survey of multiple institutions showed no survival difference in any stages and dose-rate effect ratio (HDR/LDR) was calculated to be 0.54 to 0.58. However the optimum treatment doses and fractionation schemes appropriate to generate clinical results comparable to conventional LDR schemes have yet to be standardized. In conclusion, HDR intracavitary radiotherapy is increasingly practiced in Korea and an effective treatment modality for cervical cancer. To determine the optimum radiotherapy dose and fractionation schedule, a nation-wide prospective study is necessary in Korea. In addition, standardization of HDR application (clinical, computer algorithms, and dosimetric aspects) is necessary.