• Proceedings of the Korean Nuclear Society Conference
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• 1997.10a
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• pp.528-533
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• 1997

A CANFLEX(CANdu FLEXible fuelling) 43-element bundle has developed for a CANDU-6 reactor as an alternative of 37-element fuel bundle. The design has two diameter elements (11.5 and 13.5㎜) to reduce maximum element power rating and buttons to enhance the critical heat flux(CHF), compared with the standard 37-element bundle. The freon CHF experiments have performed for two series of CANFLEX bundles with and without buttons with a modelling fluid as refrigerant H-l34a and axial uniform heat flux condition. Evaluating the effects of buttons of CANFLEX bundle on CHF and Critical Channel Power(CCP) with the experimental results, it is shown that the buttons enhance CCP as well as CHF. All the CHF's for both the CANFLEX bundles are occurred at the end of fuel channel with the high dryout quality conditions. The CHF enhancement ratio are increased with increase of dryout quality for all flow conditions and also with increase of mass flux only lot high pressure conditions. It indicates that the button is a useful design lot CANDU operating condition because most CHF flow conditions for CANDU fuel bundle are ranged to high dryout quality conditions.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2020.06a
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• pp.155-156
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• 2020

Unlike new construction projects, road paving maintenance work shows large productivity discrepancies depending on the conditions of the worksite. The current construction cost calculation scheme, however, only provides daily construction volume categorized by work scope and scale: There are no detailed standards that can be implemented on various types of worksites. To develop standards that enable the calculation of appropriate construction costs by taking into account worksite conditions, the current study conducted on-site surveys and interviews. The on-site research and analysis revealed that location, construction width, the day's worksite lot, work scope, and construction objectives were found to cause differences in construction volume. In addition to the existing work scope and work scape variables, the current study added weight constants reflecting the daily work volume based on movement conditions at site and the size of the worksite lot. In this process, the current study found that even one type of construction project can have fifteen different levels of daily construction volume. Such detailed classification was deemed to enable the proper calculation of construction costs based on worksite conditions.

• Journal of the Korean Operations Research and Management Science Society
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• v.25 no.3
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• pp.49-64
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• 2000

A vendor supplies a product to a sole/major buyer on a lot-for-lot basis under deterministic inventory control conditions. The basic premise is that the setup cost reduction technologies are available to both the buyer and the vendor, and that the vendor's inventory and setup reduction investment costs differ from the buyer's. Therefore, an individually designed ordering and setup cost reduction policy will likely cause mismatches between the vendor's and the buyer's optimal cycle times. For this situation, we show that a joint optimal setup cost reduction and ordering policy, together with an appropriate side payment(quantity discount or premium price) schedule, can be designed in a spirit in a spirit of coordination to eliminate mismatches in individual optimal cycle times.

• Journal of the Korean Institute of Navigation
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• v.8 no.1
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• pp.17-48
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• 1984

The economy of ship's size and speed is affected by the freight rates, sailing distances, cargo handling rates, fuel oil prices and even interest rates of the borrowed funds. It can be a step more powerful measures if the economic evaluation model takes in a cargo lot size which prevails in the shipping markets. This paper has dealt with hypothetical cargo lots which happen to the market with uniform distribution in probability. The evaluation models are either profit maximization method or cost minimization method. The former compares among different voyages in profitability to the invested funds, the later defines the transportation efficiency in ton-mile unit and be used in comparing two or more transportation means. This paper adopted both of above methods to derive out ships economical evaluation contours for the various ship's speed and deadweight for certain cargo lot sizes, which can be used as important managerial decision data in purchasing ships or selecting a most profitable one among the proposed voyages. This evaluation contours will also be efficiently used in appraising so called "handy size ships" in connection with port water depth and conditions of voyage tracks.ge tracks.

• Fashion & Textile Research Journal
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• v.11 no.2
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• pp.350-358
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• 2009

This research has a purpose to examine the actual conditions of natural dyeing program as a personal learning experience, participants' characteristics and common people's interest on natural dyeing nowadays. To examine the actual conditions of natural dyeing center and programs, many web sites and newspapers dealing with natural dyeing were used as main resources. As common people's interest on natural dyeing increased, there were a lot of natural dyeing centers in around country. To examine the interest on natural dyeing and the participants' characteristics of natural dyeing program, the data was obtained from a convenient survey of 326 respondents over 15 years old during 15th, May~30th, July in 2006. Almost 40% of respondents were interested in natural dyeing, but only 19% of respondents had ever participated in natural dyeing experience program. The participants' characteristics such as motivation, participating time, dyeing sources and materials, etc. were examined. Almost 65% of respondents were satisfied with natural dyeing experience. As long as people have interest on natural dyeing, Industrialization of natural dyeing will be advanced.

• Proceedings of the Safety Management and Science Conference
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• 2002.05a
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• pp.237-241
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• 2002

This paper deals with the problem of determining the buyer's economic lot sizing policy for exponentially deteriorating products under trade credit. It is also assumed that the ordering cost consists of a fixed set-up cost and a freight cost, where the freight cost has a quantity discount offered due to the economies of scale. We formulate the mathematical model and the solution algorithm is developed based on the properties of an optimal solution.

• Journal of Institute of Control, Robotics and Systems
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• v.11 no.11
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• pp.956-962
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• 2005

This paper presents an integrated analysis of production and financing decisions. We assume that a cash storage unit is installed to manage the cash flows related with production activities such as raw material procurement, process operating setup, Inventory holding cost and finished product sales. Temporarily financial investments are allowed for more profit. The production plant is modeled by the Batch-Storage Network with Recycle Streams in Yi and Reklaitis (2003). The objective function of the optimization is minimizing the opportunity costs of annualized capital investment and cash/material inventory while maximizing stockholder's benefit. No depletion of all the material and cash storage units is major constraints of the optimization. A novel production and inventory analysis formulation, the PSW(Periodic Square Wave) model, provides useful expressions for the upper/lower bounds and average level of the cash and material inventory holdups. The expressions for the Kuhn-Tucker conditions of the optimization problem can be reduced to two subproblems and analytical lot sizing equations under a mild assumption about the cash flow pattern of stockholder's dividend. The first subproblem is a separable concave minimization network flow problem whose solution yields the average material flow rates through the networks. The second subproblem determines the decisions about financial Investment. Finally, production and financial transaction lot sizes and startup times can be determined by analytical expressions as far as the average flow rates are calculated. The optimal production lot and storage sizes considering financial factors are smaller than those without such consideration. An illustrative example is presented to demonstrate the results obtainable using this approach.

• International Journal of Air-Conditioning and Refrigeration
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• v.14 no.1
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• pp.28-39
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• 2006

Two-phase flow through a T-junction has been studied by numerous researchers so far. The dividing characteristics of the gas and liquid phases at the T-junction are very complicated due to a lot of related variables. The prediction models have been suggested by using experimental data for a specific condition or working fluid. But, they showed the application limitation for the most of the other conditions or fluids. Since most of them are applicable for their own experimental range, the generalized model for the wide range of conditions and fluids is needed. Even though it's not available now, some of the models developed for air-water flow at a T-junction might be applicable for the part of refrigerants with some modifications. Especially, for the two-phase flow of refrigerants at the T-junction, very few studies have been performed. Further experimental study is required to be performed for the wide range of test conditions and fluids to predict properly the two-phase flow distribution and phase separation through the T-junction.

• Proceedings of the KIEE Conference
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• 1998.11a
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• pp.344-346
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• 1998

The OBCS(On-Board Computer System) achieves train system diagnosis and control. For commercial train operation, it must guarantee the reliability for safe and have low cost operational algorithm. To guarantee the diagnosis function and the control ability of OBCS, sufficient actual railway running test under severe conditions is required. But, running test has some limitations for making severe conditions because of safety and it demands quite long time and a lot of costs. So simulator is required and is utilized in many countries. We designed a simulator to test various functions and performance of controllers for high speed train's power car under various conditions and it is represented briefly.

• Korean Institute of Interior Design Journal
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• v.17 no.4
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• pp.66-74
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• 2008

A form of consumption has been changed to a form of pursuing rather qualitative sides than quantitative sides according to an improvement of the living level followed by an increase in national income and to an increase in women's advance to society in modern society. The above change had a lot of effects on children play space, a subsidiary means within commercial facilities. However, partial children play facilities have steady children injury cases by a lack of safety management facilities. Therefore, the study investigated indoor children play facilities installed in large-scale distribution stores as department stores and discount stores out of commercial facilities in Seoul. The study investigated actual conditions and collected picture data with a checklist drawn up on the basis of the safety management standard for three months from April, 2008 to June, 2008 by visiting five places under cooperation. The purpose of the study was to grasp actual conditions of safety management of play space within commercial facilities through the contents and picture data of the investigated checklist and to offer basic data in the side of safety management of commercial facilities and various indoor children play spaces by proposing security measures for the problems.