• Journal of KIISE:Databases
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• v.30 no.6
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• pp.629-640
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• 2003

A shared disk (SD) cluster couples multiple nodes for high performance transaction processing, and all the coupled nodes share a common database at the disk level. In the SD cluster, a transaction routing corresponds to select a node for an incoming transaction to be executed. An affinity-based routing can increase local buffer hit ratio of each node by clustering transactions referencing similar data to be executed on the same node. However, the affinity-based routing is very much non-adaptive to the changes in the system load, and thus a specific node will be overloaded if transactions in some class are congested. In this paper, we propose a dynamic transaction routing scheme that can achieve an optimal balance between affinity-based routing and dynamic load balancing of all the nodes in the SD cluster. The proposed scheme is novel in the sense that it can improve the system performance by increasing the local buffer hit ratio and reducing the buffer invalidation overhead.

• Journal of the Korean Society of Clothing and Textiles
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• v.29 no.7 s.144
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• pp.959-967
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• 2005

The color of apparels has the interaction of the face skin colors of the wearers. This study was carried out to classify the face skin colors of Korean males into several similar face skin colors in order to extract favorable colors which flatter to their face skin colors. The criterion that select the new subjects who have the classified face skin colors have to be decided. With color spectrometer, JX-777, face skin colors of subjects were measured quantitatively and classified into three clusters that had similar hue, value and chroma with Munsell Color System. Sample size was 418 Korean males and other 15 of new males subjects. Data were analyzed by K-means cluster analysis, ANOVA, Duncan multiple range test, Stepwise discriminant analysis using SPSS Win. 12. Findings were as follows: 1. 418 subjects who have YR colors were clustered into 3 kinds of face skin color groups. 2. Discriminant variables of face skin colors was 4 variables : L value of forehead, v value of cheek, c value of forehead, and b value of cheek from standardized canonical discriminant function coefficient 1 and c value of forehead, L value of forehead, b value of cheek. and L value of cheek from standardized canonical discriminant function coefficient 2. 3. Hit ratio of type 1 was $92.3\%$, of type 2 was $96.5\%$ and of type 3 was $92.6\%$ by the canonical discriminant function of 4 variables. 4. The canonical discriminant function equation 1 and 2 were calculated with the unstandardized canonical discriminant function coefficient and constant, the cutting score, and range of the score were computed. 5. The criterion that select the new subjects who have the classified face skin colors was decided.

• Proceedings of the Korea Water Resources Association Conference
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• 2009.05a
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• pp.1590-1596
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• 2009

최근 기후변화의 영향으로 인한 기상이변으로 인해 세계적으로 많은 피해가 발생하고 있으며, 규모도 점점 커지고 있다. 특히 가뭄에 대한 피해는 더욱 더 심화되는 현상으로 보이고 있다. 본 연구에서는 국내에 적합한 월단위와 주단위 가뭄전망을 제시하였다. 월단위 전망에서는 앙상블 기법을 기반으로 기상청에서 제공하는 월간산업기상정보의 적용에 따른 가뭄전망 정확성을 비교하였다. 주단위 전망에서는 기상청에서 제공하는 GDAPS를 이용하여 확정론적 가뭄전망을 하였다. 가뭄지수로서는 강수, 유량, 지하수위를 인자로 하는 MSWSI(Modified Surface Water Supply Index)를 가뭄지수로 사용하였으며, MSWSI는 5개 구간으로 나누었다. 월단위 가뭄전망에서는 물수지모형인 abcd모형에 과거 강수와 잠재증발산량 시나리오를 입력변수로 하여 최종적으로 유량과 지하수위 시나리오를 생산하여, 확률 가뭄전망을 위해 각 구간의 발생확률을 산정하고 실측자료로부터 산정한 MSWSI와 비교하였다. 정확성 평가를 위해서 RPS(Ranked Probability Score)를 이용하였다. 금강유역에 적용한 결과, 이수기(10월-이듬해 6월)에는 4개 달이 초보전망보다 높았으나 전체 RPS는 1.87로서 초보전망의 1.84보다 높아 현재 월단위 가뭄전망기법에는 많은 불확실성이 존재하였다. 또한 월간산업기상정보를 이용한 월단위 가뭄전망에서도 초보전망보다 정확성이 낮아, 현재 중장기 기상정보를 이용하기에는 어려운 것으로 나타났다. 주단위 가뭄전망에서는 abcd모형에 GDAPS를 입력변수로 하여 확정론적 MSWSI를 산정하여 실측자료로부터 산정한 MSWSI와 비교하였으며, Hit ratio를 이용하여 그 정확성을 평가하였다. 주단위 가뭄전망 결과, 주단위 가뭄전망의 Hit ratio가 0.480으로서 초보전망보다 높아 주단위 가뭄전망은 효용성이 있음을 입증하였다. 본 연구에서 적용기간이 짧아 가뭄전망의 정확성을 판단하기는 이르나, 월단위 가뭄전망에서는 기상정보의 정확성이 향상에 따라 가뭄전망의 정확성도 향상될 것으로 판단된다. 장기적으로 본 연구 결과를 토대로 단기와 중장기 가뭄전망을 수행하고 평가한다면, 가뭄전망에 대한 신뢰도가 더 높아질 것으로 사료된다.

• Journal of the Korean Operations Research and Management Science Society
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• v.28 no.3
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• pp.81-101
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• 2003

The financial statements purpose to provide useful information to decision-making process of business managers. The value-relevant information, however, embedded in the financial statement has been often overlooked in Korea. In fact, the financial statements in Korea have been utilized for nothing but account reports to Security Supervision Boards (SSB). The objective of this study is to develop earnings forecasting models through financial statement analysis using artificial intelligence (AI). AI methods are employed in forecasting earnings: artificial neural networks (ANN) for manufacturing industry and case~based reasoning (CBR) for banking industry. The experimental results using such AI methods are as follows. Using ANN for manufacturing industry records 63.2% of hit ratio for out-of-sample, which outperforms the logistic regression by around 4%. The experiment through CBR for banking industry shows 65.0% of hit ratio that beats the statistical method by 13.2% in holdout sample. Finally, the prediction results for manufacturing industry are validated through monitoring the shift in cumulative returns of portfolios based on the earning prediction. The portfolio with the firms whose earnings are predicted to increase is designated as best portfolio and the portfolio with the earnings-decreasing firms as worst portfolio. The difference between two portfolios is about 3% of cumulative abnormal return on average. Consequently, this result showed that the financial statements in Korea contain the value-relevant information that is not reflected in stock prices.

• The KIPS Transactions:PartA
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• v.14A no.5
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• pp.269-278
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• 2007

Caching in a cache sorrel cluster environment has an advantage that minimizes the request and response tine of internet traffic and web user. Then, one of the methods that increases the hit ratio of cache is using the hash function with cooperative caching. It is keeping a fixed size of the total cache memory regardless of the number of cache servers. On the contrary, if there is no cooperative caching, the total size of cache memory increases proportional to the number of cache sowers since each cache server should keep all the cache data. The disadvantage of hashing method is that clients' requests stress a few servers in all the cache servers due to the characteristics of hashing md the overall performance of a cache server cluster depends on a few servers. In this paper, we propose the method that distributes uniformly client requests between cache servers using dynamic server information. We performed experiments using 16 PCs. Experimental results show the uniform distribution o

• Journal of KIISE:Computing Practices and Letters
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• v.9 no.4
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• pp.410-419
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• 2003

The buffer cache of general operating systems such as Linux manages file data by using global block replacement policy and read ahead. As a result, multimedia data with a low locality of reference and various consumption rate have low cache hit ratio and consume additional buffers because of read ahead. In this paper we have designed and implemented a new buffer allocation algorithm for multimedia data on Linux. Our approach keeps one read-ahead cache per every opened multimedia file and dynamically changes the read-ahead group size based on the buffer consumption rate of the file. This distributes resources fairly and optimizes the buffer consumption. This paper compares the system performance with that of Linux 2.4.17 in terms of buffer consumption and buffer hit ratio.

• Journal of the Korea Society of Computer and Information
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• v.19 no.7
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• pp.113-130
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• 2014

In this paper, we propose BLOCS algorithm to find sequence of data that should be saved in cache device of hybrid storage system which uses SSD as a cache device. BLOCS algorithm which uses a sequence pattern mining scheme, creates a set of frequently requested sectors with respect to requested order of sectors. To compare the performance of the proposed scheme, we introduce Distance (DIST) based scheme, Request Frequency (FREQ) based scheme, and Frequency times Size (F-S) based scheme. We measure the hit ratio and I/O latency of different caching schemes using hybrid storage caching simulator. We acquired booting workload along with ten scenarios of launching applications and use the workloads as input to the cache simulator. After experiment with booting workload, we find that BLOCS scheme gives hit ratio of 61% which is about 15% higher than the least performing DIST scheme.

• Journal of Korean Society of Water and Wastewater
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• v.30 no.1
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• pp.59-67
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• 2016

Owing to time and cost constraints, new methods that would make it possible to evaluate the safety of the water supply pipeline in a less time- and cost-consuming manner are urgently needed. In response to this exigency, the present study developed a new statistical model to assess the safety of the water supply pipeline using the quantification theory type II. In this research, the safety of the water supply pipeline was defined as 'a possibility of the pipeline failure'. Quantification analysis was conducted on the qualitative data, such as pipe material, coating, and buried condition. The results of analyses demonstrate that the hit ratio of the quantification function amounted to 77.8% of hit ratio, which was a fair value. In addition, all variables that were included in the quantification function were logically valid and demonstrated statistically significant. According to the results derived from the application of the safety evaluation model, the coefficient of determination ($R^2$) between K-region's water supply pipeline safety and the safety inspection amounted to 0.80. Therefore, these findings provide meaningful insight for the measured values in real applications of the model. The results of the present study can also be meaningfully used in further research on safety evaluation of pipelines, establishing of renewal prioritization, as well as asset management planning of the water supply infrastructure.

• Journal of Sasang Constitutional Medicine
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• v.7 no.2
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• pp.89-100
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• 1995

This study was conducted for the purpose of finding out an objective classification method for Sasang Constitutional medicine, which divides people into 4 groups of constitution and presents comprehensively physiology, pathology, diagnosis, therapy and recuperation regarding each constitution. Questionnaire of Sasang Constitution Classification(I) was administered to 328 inpatients at Kyung Hee Oriental Medicine Hospital. Data was collected during 10 months from June 1994 to Mar. 11, 1995. For the purposes of this study, the collected data was analyzed by crosstabs, variation analysis, and discrimination analysis. The analyzing program was SPSS PC+V4.0. For the purposes of this study, the collected data was analyzed by crosstabs, cariation analysis, and discrimination analysis. The analyzing program was SPSS PC+V4.0. The results were as follows : 1. There was significant differences of each group scales through variation analysis. The questions of each group had Sasang constitutional diagnostic discrimination abilities 2. The diagnostic discrimination abilities(Hit-ratio=56.10%) of the Questionnaire for Sasang Constitution Classification(I) were found to have over 20% improvement than the propotional chance criteria(33.3%), Especially, Hit-ratio for $So{\breve{u}}m$-In(63%) was higher than that of SoYang-In(55%) and $Ta{\breve{e}}um$-In(56.3%). 3. Through discrimination analysis on good questions of each group, the diagnostic discrimination abilities of the Questionnaire for Sasang Constitution Classification(I) was 57.93%. 4. This would be on the ground that the Questionnaire for Sasang Constitution Classification(I) could be used as a tool for Sasang constitution classification.

• The Journal of Korean Medicine
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• v.26 no.1 s.61
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• pp.93-102
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• 2005

Objective : This research was conducted to evaluate the method of sasangin classification by voice analysis, The 2 pilot tests were thus designed to solve the following problems: 'What are the conditions at classification for sasangin by the voice analysis?' and 'What are the important variances of /a/ parameter?'. Methods: 122 volunteers Were examined to make a diagnosis of sasangin by QSCC II and they were disease-free and healthy, First, they said /a/ three times for 2 seconds in their usual voice, Second, they said /a/ for 2 seconds by the different ways of high tone, mid tone, and low tone. The sounds were collected by a recording program (cooledit 2000) through a Sony microphone (ecm-26l). We analyzed the voices by maltlab, the simulation tool. Results: There were no differences and were correlations when one said /a/ three times for 2 seconds in the usual voice. There were some things to correlate when one said /a/ three times for 2 seconds by the different ways of high speech, usual speech, and low speech. Others were nothing to correlate. We evaluated the value of sasangin classification method by only /a/ voice analysis. The hit ratio was average $66.3\%\;:\;soyangin\;67.9\%,\;taeumin\;68.0\%,\;soeumin\;63.9\%$. Conclusion: We must set up the conditions to use the method of sasangin classification by voice analysis. The value of sasangin classification method by only fa! voice analysis was a hit ratio of $66.3\%$.