• Journal of the Korean Society of Hazard Mitigation
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• v.9 no.3
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• pp.127-133
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• 2009

In this study, dimensionless-cumulative rainfall curves were generated by multivariate Monte Carlo method. For generation of rainfall curve rainfall storms were divided and made into dimensionless type since it was required to remove the spatial and temporal variances as well as differences in rainfall data. The dimensionless rainfall curves were divided into 4 types, and log-ratio method was introduced to overcome the limitations that elements of dimensionless-cumulative rainfall curve should always be more than zero and the sum total should be one. Orthogonal transformation by Johnson system and the constrained non-normal multivariate Monte Carlo simulation were introduced to analyse the rainfall characteristics. The generative technique in stochastic rainfall variation using multivariate Monte Carlo method will contribute to the design and evaluation of hydrosystems and can use the establishment of the flood disaster prevention system.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.32 no.2
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• pp.66-75
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• 2009

As the population of the silver generation is increasing, the importance and effects of the market for the silver generation are also growing. We segments the categories of the silver generation into six sub-segments using based on the factors like life style, life stage, or performing role from the point of view in communication industry. After segmenting those categories, we observed the experience of each segmented group in detail. Likewise, we executed both FGD(Focused Group Discussion) and participants' observations together to effectively collect the expressed and/or potential needs. Customer's experience was collected along the touch points and customer corridors after dividing the customer's experience world into two groups; communication styles in usual life (life log) and direct contact channels. The effects of delivering an affirmative customer's experience would be empowered by eliminating negative experiences or complementing affirmative experiences. For this purpose, this paper presents the improvement points for the better customer's experience based on the observed customer's experience. This paper presented a sample way of customer-centric approach to design the services or products in the communication industry. In addition to that, the analyzed results of this paper will be useful to find out an effective approach to the market of silver generation.

• Convergence Security Journal
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• v.4 no.2
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• pp.9-15
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• 2004

The Internet is aggregate of trustless networks essentially Because the Internet is very difficult to control flowing of information, taking advantage of enough sporadic resource, security problem that can protect internal important stock from the Internet is risen seriously. Recently, virus accident and generation rate about system intrusion that happen become much higher and various than past. On these time, is progressing researcher for invasion cutout to keep away illegal act vigorouslyand do continuous development. In this paper, reporting administrator log information about invader's illegal act depending on XML format form, and I wished to solve problem that happen in administration side developing invasion interception system that can control to remote.

• The Korean Journal of Mycology
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• v.38 no.1
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• pp.25-28
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• 2010

New shiitake(Lentinula edodes) strain "Sanlim No. 7" was produced by Di-mon hybridization method. Bed-log cultivation of Sanlim No. 7 was performed. Fruit-body production was most at autumn and it is suitable to use as fresh shiitake rather than dried one. The fruit body is hemispherical shape, brown coloured and diameter of pileus is ca. 47 mm. Row of gill is straight, and its width is narrow. Optimum temperature of fruit-body formation was $11{\sim}23^{\circ}C$, and the fruiting is sporadic. The total amount of fruit-body production during 4 years(one generation) was ca. 1.4 kg/log.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.34 no.12C
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• pp.1197-1207
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• 2009

Orthogonal Frequency Division Multiple Access (OFDMA) is widely used as a multiple access technique for next generation mobile communication systems, however, its main drawback is the high peak-to-average ratio (PAPR). Thus for the uplink case where the transmit power is strictly limited due to the battery life of mobile units, single carrier frequency division multiple access (SC-FDMA) with low PAPR is preferred to OFDMA method. In this paper, we propose a method to improve the performance of SC-FDMA using frequency domain MMSE equalization. The proposed improved log-likelihood ratio (LLR) generation method exploits both the diversity characteristic of channels and the reciprocity that is obtained from the received signals. The complexity of the proposed method is analyzed and its performance gain is demonstrated via a set of computer simulations.

• 한국IT서비스학회:학술대회논문집
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• 2009.11a
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• pp.343-350
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• 2009

대규모 금융권 차세대 프로젝트에서 테스트에 대한 중요성은 재무RISK 관점에서 뿐만 아니라 소프트웨어 품질향상을 위한 결함의 제거 관점에서도 그 의미가 크다. 대규모 차세대 프로젝트는 일반 프로젝트에 비하여 개발되는 소프트웨어의 양이 방대하고 개발참여인원도 일반적인 관리수준을 넘어 수작업에 의한 테스트만으로는 충분한 품질을 보장하지 못한다. 또한 테스트를 수행한 이후에도 지속적으로 변경이 발생하고 이를 반영하는 과정에서 많은 결함이 유입되는 현재의 SI 프로젝트 특성상 지속적인 테스트 및 반복적인 검증만이 소프트웨어의 품질을 보장할 수 있다. 본 논문에서는 code coverage testing기법을 활용하여 동적 테스트 수행결과를 log로 도출하고, log 분석 결과를 통해 소프트웨어 품질의 향상을 기대할 수 있는 방안을 제시한다.

• Communications for Statistical Applications and Methods
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• v.29 no.4
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• pp.453-469
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• 2022

The study of immune cellular composition has been of great scientific interest in immunology because of the generation of multiple large-scale data. From the statistical point of view, such immune cellular data should be treated as compositional. In compositional data, each element is positive, and all the elements sum to a constant, which can be set to one in general. Standard statistical methods are not directly applicable for the analysis of compositional data because they do not appropriately handle correlations between the compositional elements. In this paper, we review statistical methods for compositional data analysis and illustrate them in the context of immunology. Specifically, we focus on regression analyses using log-ratio transformations and the alternative approach using Dirichlet regression analysis, discuss their theoretical foundations, and illustrate their applications with immune cellular fraction data generated from colorectal cancer patients.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.29 no.4
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• pp.719-728
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• 2019

Recently, there has been a growing market for shared mobility businesses that share 'transport' such as cars and bikes, and many operators offer a variety of services. However, if the fare can not be charged normally because of security vulnerability, the operator can not continue the business. So there should be no security loopholes. However, there is a lack of awareness and research on shared mobility security. In this paper, we analyzed security vulnerabilities exposed in application log of shared bike service in Korea. We could easily obtain the password of the bike lock and the encryption key of the AES-128 algorithm through the log, and confirmed the data generation process for unlocking using software reverse engineering. It is shown that the service can be used without charge with a success rate of 100%. This implies that the importance of security in shared mobility business and new security measures are needed.

• Water for future
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• v.7 no.1
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• pp.71-77
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• 1974

This paper reviews several different single site generation models for further development of a model for generating the Synthetic sequences of streamflow in the continuous streams like main streams in Korea. Initially the historical time series is looked using a time series technique, that is correlograms, to determine whether a lag one Markov model will satisfactorily represent the historical data. The single site models which were examined include an empirical model using the historical probability distribution of the random component, the linear autoregressive model(Markov model, or Thomas-Fiering model) using both logarithms of the data and Matala's log-normal transformation equations, and finally gamma distribution model.

• The KIPS Transactions:PartD
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• v.15D no.6
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• pp.755-766
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• 2008

Recently, NAND flash memory is becoming into the spotlight as a next-generation storage device because of its small size, fast speed, low power consumption, and etc. compared to the hard disk. However, due to the distinct characteristics such as erase-before-write architecture, asymmetric operation speed and unit, disk-based systems and applications may result in severe performance degradation when directly implementing them on NAND flash memory. Especially when a B-tree is implemented on NAND flash memory, intensive overwrite operations may be caused by record inserting, deleting, and reorganizing. These may result in severe performance degradation. Although ${\mu}$-tree has been proposed in order to overcome this problem, it suffers from frequent node split and rapid increment of its height. In this paper, we propose Log-Structured B-Tree(LSB-Tree) where the corresponding log node to a leaf node is allocated for update operation and then the modified data in the log node is stored at only one write operation. LSB-tree reduces additional write operations by deferring the change of parent nodes. Also, it reduces the write operation by switching a log node to a new leaf node when inserting the data sequentially by the key order. Finally, we show that LSB-tree yields a better performance on NAND flash memory by comparing it to ${\mu}$-tree through various experiments.