• Proceedings of the KIEE Conference
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• 1998.07c
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• pp.899-901
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• 1998

Continuation power flow is a tool that can trace the path of the solution from the base stable solution. However, the base stable solution cannot be calculated when the initial system load is too large to operate at a stable operating point. This case is called as unsolvable case. This paper presents implementation of the optimal load shedding algorithm on continuation power flow. It performs steady-state analysis of power systems at unsolvable case that can occur in contingency analysis. Numerical simulation on 20-bus test system demonstrates that the continuation power flow applying the optimal load shedding algorithm is robust at solvable and unsolvable cases.

• Proceedings of the Korea Inteligent Information System Society Conference
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• 2001.06a
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• pp.445-454
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• 2001

A workflow model is useful fur business process analysis and has often been implemented for office automation through information technology. Accordingly, the results of workflow modeling need to be systematically managed as information assets. In order to manage the modeling process effectively, it is necessary to enhance the efficiency of their reuse. Therefore, this paper creates a Document-barred Workflow Modeling Support System (DWMSS) using a case-based reasoning (CBR) approach. It proposes a system architecture, and the corresponding modeling process is developed. Furthermore, a repository, which consists of a case base and vocabulary base, is built. A carte study is illustrated to demonstrate the usefulness of th is system.

• The KIPS Transactions:PartD
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• v.11D no.5
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• pp.1189-1196
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• 2004

It is a major concern of e-shopping mall managers to satisfy a variety of customer's desire by recommending a proper product to the perspective purchaser. Customer information like customer's fondness, age, gender, etc. in shopping has not been used effectively for the customers or the suppliers. Conventionally, e-shopping mall managers have recommended specific items of products to their customers without considering thoroughly in a customer point of view. This study introduces the ways of a choosing and recommending of products using case-based reasoning and rule-based reasoning for customer themselves or others. A similarity measure between one member's idiosyncrasy and the other members' is developed based on the rule base and the case base. The case base is improved for the system intelligence by recognizing and learning the changes of customer's desire and shopping trend.

• Journal of the Korean Society of Propulsion Engineers
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• v.16 no.1
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• pp.72-78
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• 2012

The position effect of the solid propellant in the combustion chamber on the decrease of the differential pressure has been investigated using the IBcode. Generally the metallic cartridge or CCC (combustible cartridge case) are used to load the propellant of the gun propulsion system. The position of the cartridge(propellant) is, therefore, a major factor for the interior ballistics in case the combustion chamber is larger than the cartridge. In this study, three different positions in the empty space of the chamber have been considered. As results, the case of the propellant located in the region near the base and breech has shown that the negative differential pressure and the difference between the breech pressure and the base pressure are much higher than those of the case of the propellant located in the center of the chamber. The case of the propellant in the center of the chamber is, therefore, more profitable to improve the performance of the interior ballistics.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2011.04a
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• pp.236-241
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• 2011

The position effect of the solid propellant in the combustion chamber on the decrease of the differential pressure has been investigated using the IBcode. Generally the metallic cartridge or CCC (combustible cartridge case) as the propellant for the cannon has been loaded. The position of the propellant(cartridge) is, therefore, a major factor for the interior ballistics in case the combustion chamber is larger than the cartridge. In this study, three cases of the existence of empty space in the chamber has been considered. As results, the case of the propellant located in the region near the base and breech has shown that the negative differential pressure and the difference between the breech pressure and the base pressure are much higher than those of the case of the propellant located in the center of the chamber. The case of the propellant in the center of the chamber is, therefore, more profitable to improve the performance of the interior ballistics.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.30 no.3
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• pp.89-93
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• 2007

In this study, we consider an assembly line operated under a base-stock policy. A product consists of two parts, and a finished product transfers to a warehouse in which demands are satisfied. Assume that demands arrive according to a Poisson process and processing times at each production line are exponentially distributed. Whenever a demand arrives, it is satisfied immediately from an inventory in the warehouse if available; otherwise, it is backlogged and satisfied later by the next product exiting from production lines. In either case, an arriving demand automatically triggers the production of a part at both production lines. These two parts will be assembled into a product that eventually transfers to the warehouse. We obtain a closed form formula of approximation for delay time or lead time distribution of a demand when a base- stock level is s. Moreover, it can be applied to the optimal base-stock level which minimizes the total inventory cost. Numerical examples are presented to show our optimal base-stock level's quality.

• Korean Journal of Environment and Ecology
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• v.29 no.6
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• pp.936-946
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• 2015

This study is aimed to analyze the reduction performance of building energy consumption according to planting base types of panel-type green walls which can be applied to existing buildings. The performance was compared to the general performance of green walls that have demonstrated effects of improving the thermal environment and reducing building energy consumption in urban areas. The number of planting base types was 4 in total, and simulations were conducted to analyze the thermal conductivity, thermal transmittance, and overall building energy consumption rate of each planting base type. The highest thermal conductivity by the planting base type was Case C (0.053W/mK), followed by Case B (0.1W/mK) and Case D (0.17W/mK). According to the results of energy simulation, the most significant reduction of cooling peak load per unit area was Case C (1.19%), followed by Case B (1.14%) and Case D (1.01%) when compared to Case A to which green wall was not applied; and the most significant reduction of heating peak load per unit area was estimated to be Case C (2.38%), followed by Case B (1.82%) and case D (1.50%) when compared to Case A. The amount of yearly cooling and heating energy use per unit area showed 3.04~3.22% of reduction rate. The amount of the 1st energy use showed 5,844 kWh/yr of decrease on average for other types when compared to Case A. The amount of yearly $CO_2$ emission showed 996kg of decrease on average when compared to Case A to which the green wall was not applied. According to the results of energy performance evaluation by planting location, the most efficient energy performance was eastward followed by westward, southward and northward. According to the results of energy performance evaluation by planting location by green wall ratio, it was found that as the ratio of green wall increased, the energy performance displayed better results, showing approx. double reduction rate in energy consumption at 100% of green wall ratio than the reduction rate at 20% to 80% of green wall ratio.

• The KIPS Transactions:PartD
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• v.12D no.4 s.100
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• pp.531-542
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• 2005

In this paper, we propose the MDBMS(Multi-DataBase Management System) which integrates the LDBMSs(Local DataBase Systems) with heterogeneous environment into distributed system and provides global users with rapidly query process. For designing the MDBMS, we define the functions of components and design the interaction among them. In a point of view of the global view manager in components, we describe the following 3 cases; (1)the case which the results for the global query are all stored to the global view repository, (2)the case which no result exists in the global view repository, and (3)the case which the partial results we stored to the global view repository. By comparing above cases, we establish the functionalities of our MDBMS through the sequence diagram including the interlace of among objects and the method calling. Finally, we propose the model designed in the concrete by showing the executing procedures of each function using sample query on established functions mentioned above.

• Journal of Welding and Joining
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• v.24 no.1
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• pp.56-63
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• 2006

The characteristics of $CO_2$ or Nd:YAG laser welded 600MPa ade TRIP steel was investigated. He or Ar gas was used as a shield gas in case of $CO_2$ laser welding, but the shield gas was not used in case of Nd:YAG laser welding. Bead on plate welding was performed with various welding conditions. Defects in the joints of both welding type occurred at 1.8m/min but were not observed over the welding speed of 2.1m/min in case of Nd:YAG laser welding. However, porosity occurred in $CO_2$ laser welding and the tendency of decreasing with the increase of welding speed. The hardness was the highest at heat affected zone near fusion zone as well as at the fusion zone and decreased on approaching the base metal. In a perpendicular tensile test to the weld line, all specimens that have been welded at optimum conditions were fractured at the base metal, and the tensile properties showed the rather higher than those of raw material. In a parallel tensile test, the strength of the joints was higher than that of the base metal. Elongation was found to be lower than that of the raw material. Forming height by Erichsen test and elongation were deeply related with the ratio of base metal/weld metal and the maximum hardness of the weld metal. Also porosity induced to decrease the strength and the elongation. The maximum formability was recorded at approximately 80% as compared with that of the raw material with the optimum condition.

• Journal of Appropriate Technology
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• v.5 no.2
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• pp.97-105
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• 2019

Most of the BoP (Base of the Pyramid) do not have the economic power to eat balanced nutrients. Therefore, the solution is to add essential nutrients to the food you eat. This method can improve nutrition without putting an economic burden on the BoP classes. The aim of the paper is to apply the strategic management process for analysing BoP solutions in nutrition improvement sector. This allows identification of critical aspects in developing BoP solutions. This includes reaching sustainability related objectives. Two cases (Ajinomoto, Grameen Danone) covering both products and services have been researched, allowing a contribution towards the applicability of strategic management in respective situations. In this study, we analyzed the case through the "Appropriate Technology 2.0" framework of Polak and Warwick (2014). In addition, we introduced the strategy of BoP business. Based on the results of this analysis, we analyzed the success factors of appropriate technology business in the emerging markets through the 4A model.