• CDE review
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• v.21 no.2
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• pp.69-74
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• 2015

A Sudoku puzzle is a kind of magic square puzzle which requires a non-repeated series of numbers from 1 to 9 in each 9 rows and 9 columns. Furthermore it contains total of 9 small three-by-three matrices, which need non-repeated numbers from 1 to 9 as well. Therefore the total number of possible cases of Sudoku puzzle is finite, even though that of creating nine-by-nine square is exponentially great. Accordingly a certain set of way is need not only for solving the puzzle, but also creating a new one. In this study, the method for creating a Sudoku puzzle applying genetic algorithm is suggested and will be demonstrated. Also, it will be shown that a Sudoku puzzle can be solved by genetic algorithm.

• Water Engineering Research
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• v.1 no.2
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• pp.159-168
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• 2000

In this paper, the increment of the local scour depth at piers by constructing the bridge between existing bridges is examined through the experiments in which 5 piers in the non-cohesive bed material in the experimental flume were installed. In the experiments the maximum distance of 25 times of the pier length and the maximum distortion width of 8 times of the pier width were utilized. Through the experimental studies, it was indicated that low flow, which can be characterized as the flow having low Froude numbers, the maximum bed configuration change is obtained when the piers are installed in the straight line in the flor direction without any distortion. However, In the high flow, which can be characterized as the flow having high Froude numbers, the maximum bed configuration change is obtained when the piers are installed with some distortion from the flow direction. The influence of the bed configuration by interaction between bridge piers is changed depending upon the Froude numbers, the distance between piers, and the distortion width between adjacent bridge piers. Also, because the scour patterns are affected by the bed configuration, the maximum scour should be increased by about 60% compared to that in a single pier if the interaction between bridge piers exists. It can be suggested that the maximum scour depth at bridge piers predicted by applying the existing equations should be increased if the interaction between bridge piers exist. Those cases are found when new bridges are constructed successively in the river in the urban area.

• Korean Journal of Radiology
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• v.1 no.3
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• pp.142-151
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• 2000

Objective: To determine the optimal scan timing for contrast-enhanced magnetic resonance angiography and to evaluate a new timing method based on the arteriovenous circulation time. Materials and Methods: Eighty-nine contrast-enhanced magnetic resonance angiographic examinations were performed mainly in the extremities. A 1.5T scanner with a 3-D turbo-FLASH sequence was used, and during each study, two consecutive arterial phases and one venous phase were acquired. Scan delay time was calculated from the time-intensity curve by the traditional (n = 48) and/or the new (n = 41) method. This latter was based on arteriovenous circulation time rather than peak arterial enhancement time, as used in the traditional method. The numbers of first-phase images showing a properly enhanced arterial phase were compared between the two methods. Results: Mean scan delay time was 5.4 sec longer with the new method than with the traditional. Properly enhanced first-phase images were found in 65% of cases (31/48) using the traditional timing method, and 95% (39/41) using the new method. When cases in which there was mismatch between the target vessel and the time-intensity curve acquisition site are excluded, erroneous acquisition occurred in seven cases with the traditional method, but in none with the new method. Conclusion: The calculation of scan delay time on the basis of arteriovenous circulation time provides better timing for arterial phase acquisition than the traditional method.

• Knowledge Management Research
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• v.9 no.4
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• pp.113-125
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• 2008

Net present value (NPV) and return on investment (ROI) are commonly used to evaluate investment in new technologies. Sometimes, however, measuring the value of investment in new IT becomes very difficult due to its wide scope of application coupled with embedded options in its adoption. Therefore, comprehensive but easily understandable methodologies are needed to solve the complicated problems resulting from the complexity of new technologies. This paper employs a real option analysis to evaluate RFID adoption in the supply chain. Real options analysis should be a better way to evaluate a disruptive technology like RFID. However, the pure (probabilistic) real option rule characterizes the present value of expected cash flows and the expected costs by a single number, which is not realistic in many cases. To solve the problem, this paper considers the real option rule in a more realistic setting, namely, when the present values of expected cash flows and expected costs are estimated by trapezoidal fuzzy numbers.

• Kyungpook Mathematical Journal
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• v.50 no.1
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• pp.59-69
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• 2010

The main aim of this article is to introduce a new class of sequence spaces using the concept of n-norm and to investigate these spaces for some linear topological structures as well as examine these spaces with respect to derived (n-1)-norm. We use an Orlicz function, a bounded sequence of positive real numbers and some difference operators to construct these spaces so that they become more generalized and some other spaces can be derived under special cases. These investigations will enhance the acceptability of the notion of n-norm by giving a way to construct different sequence spaces with elements in n-normed spaces.

• Journal of Society of Preventive Korean Medicine
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• v.5 no.1
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• pp.57-75
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• 2001

This study was conducted to improve the current regulation guidelines for developing traditional Korean medicines with effectiveness and productivity, in order to cope with the upcoming ICH on specifications on oriental herbal drugs. Also, major purposes of this study are to motivate R&D and to pioneer foreign markets for domestic herbal drug companies. First, after examining concepts of traditional Korean medicines and comparing the numbers and differentiation of herbal drugs registered on Pharmacopeia among Korea, China, and Japan, the current new drug development requirements for traditional Korean medicines were reviewed in detail, followed by comparison of foreign regulation systems including USA, EU, China, and Japan. Second, empirical cases on failure of development for new traditional Korean medicines under the current regulation system in the domestic companies including Dong-A, Kwangdong, and Samchondang, were collected and analyzed. As a result, hanbangsaengyak, the new category for traditional Korean medicines was newly developed on the basis of scientification of data between saengyak and hanyak, from the perspectives of harmonization between oriental medicine and western medicine and of balance between food and drug, in terms of industrialization, publicity, modernization, and effectiveness of administration. In addition, the new regulation requirements for the new hanbangsaengyak preparations were discussed by establishing principles of reinforcing preclinical test and of simplifying clinical trials in Korea. Finally, the further researches to articulate the complete specifications for pre-clinical and clinical requirements for traditional Korean medicines were strongly suggested.

• Journal of the Korean Society for Precision Engineering
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• v.20 no.10
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• pp.169-176
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• 2003

Genetic algorithm (GA), which has a powerful searching ability and is comparatively easy to use and also to apply, is in the spotlight in the field of the optimization for mechanical systems these days. However, it also contains some problems of slow convergence and low efficiency caused by a huge amount of repetitive computation. To improve the processing efficiency of repetitive computation, some papers have proposed paralleled GA these days. There are some cases that mention the use of gray code or suggest using gray code partially in GA to raise its slow convergence. Gray code is an encoding of numbers so that adjacent numbers have a single digit differing by 1. A binary gray code with n digits corresponds to a hamiltonian path on an n-dimensional hypercube (including direction reversals). The term gray code is open used to refer to a reflected code, or more specifically still, the binary reflected gray code. However, according to proposed reports, gray code GA has lower convergence about 10-20% comparing with binary code GA without presenting any results. This study proposes new Full gray code GA (FGGA) applying a gray code throughout all basic operation fields of GA, which has a good data processing ability to improve the slow convergence of binary code GA.

• Journal of Chest Surgery
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• v.25 no.4
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• pp.438-444
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• 1992

We analysed 7,180 annual cases of surgical treatment performed by Department of Thoracic and Cardiovascular Surgery of 6 major institutes in Seoul Korea, All cases were applied to 101 of 140 coded items applicable to the field of Thoracic and Cardiovascular Surgery, in the book of "Standard Price List for Medical Service" which was notified by the Ministry of Health and Social Affairs, and of them, applied field specific items were 70 of 93 applicables. The most frequently applied items were those associated to ECC[extracorporeal circulation] 1,510 cases, and then item of closed thoracostomy 751 cases was next. Except the items associated to ECC, the coded item of the highest "Total cost[fee x total applied numbers]" was mitral valve replacement 182,356,570 won[534,770 won x 341 cases]. 140 items were arranged in "Total cost" order, and then categorized into 5 groups. Medical insurance fees of each group were modified by different grades without changes in sum of total fees. Fees of Group 1, the highest group in "Total cost" were pulled up, on the other hand, Group 4, the lowest group, were pulled down, Group 5, composed of overlapping items with other fields, were not changed. The result of adjustment by grouping showed 21.2% increment effect[535,749,105 won] in real income. And we found that new coded items for modern high technological procedures should be added to "Standard Price List for Medical Service “Standard Price List for Medical Service".

• Journal of the Korean Geotechnical Society
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• v.37 no.8
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• pp.15-24
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• 2021

Recently, cases for inevitable adjacent construction are increasing due to the limited spaces in urban area. When a new structure is constructed near an existing structure, interference effects induced by the pre-existing structure should be considered. Thus, numbers of studies have been conducted to investigate the effects of adjacent construction, while laboratory scales studies are not well reported. In this study, laboratory scale experiments have been conducted to investigate the bearing capacity and settlement variations with different adjacent construction cases. Results show an optimistic ground bearing capacity increase of the new foundation structure due to the existing foundation structure, while concerns on the increased settlement of the pre-existing structure. Thus, both bearing capacity of the new foundation structure and subsequent settlement of the existing foundation structure have to be considered when assessing the technical applicability of adjacent structure construction on site.

• Journal of Environmental Impact Assessment
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• v.19 no.2
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• pp.205-213
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• 2010

The purpose of this research is to analysis the application of the ISG(Index of Streetscape Greenness) in EIA through case study of Seoul. ISG is a new index which directly expresses human's perceptions of plants in a street and is defined as the area ratio of which leaves of plants occupy an eye-level view of a person standing on the center line of a street. In this research the 42 cases of 3 step reports such as plans, drafts, and final reports which had been passed through the EIA procedure of Seoul were analyzed. The results are as follows: In the drafts frequent mistakes or errors such as unsuitable picture composition, unsuitable sample points, inconsistency of the simulation result with the planting plan, and insufficient numbers of analysis were found, but almost of them were corrected in the final reports. In the most of final reports, the 30% of minimum requirement was satisfied. At all cases the changes of the ISG values were clearly positive. Finally the average current ISG was 19.6%, meanwhile the average proposed ISG was 35.4%. It was verified that the ISG is very practical index to promote green streetscape, but in order to guarantee an achievement a thorough investigation of reports are needed.