• Journal of the Korea Society of Computer and Information
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• v.15 no.6
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• pp.65-72
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• 2010

In ad-hoc network, the technique to efficiently consume the limited amounts of energy is an important issue since the wireless terminal node is operated on batteries as their energy resource. In order to extend the system lifetime, through a balanced energy consumption, we must delay the situation in which a particular terminal node's energy is depleted and results in system disconnection. Also, the link, which has low reliability due to the mobility of the node, should be avoided considering the key element when setting up the route. The proposed CMLR method in this paper enables to increase the efficiency of energy consumption with a new cost function considering the residue energy of node, error rate of link, and transmission energy consumption. This method is extending the network lifetime and increasing the energy efficiency by compromising the value between the minimization of the transmission energy consumption and maximization of the node's lifetime. Through the simulations the proposed CMLR algorithm was verified by showing better performance over the conventional methods in terms of network lifetime and path efficiency.

• Journal of the Korean Solar Energy Society
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• v.38 no.4
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• pp.1-9
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• 2018

PVT modules commonly can be defined as a combination of PV modules and thermal collectors. After absorbing sun light, electricity and hot water can be actually provided to users simultaneously, which dual outputs (electricity and hot water) have drawn academic interest and industrial activities. Additionally, heat exchange between solar cell and flowing water can enhance solar cell efficiency. Because of PVT modules effectiveness, new international markets and commercial products have made. Especially European, facilities and measurement methods are established to evaluate PVT module performance. However, there are no currently appropriate internationally and domestic standards and facilities to test PVT module performance Herein, to test PVT module performance, indoor thermal simulators and fundamental standard study are considered.

• Archives of design research
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• v.18 no.3 s.61
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• pp.191-198
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• 2005

Menu is the most common interaction tool to select and execute a specific menu item from multiple menu options. With the very rapid increasing amount of information, various new menu designs have been developed. In this research, the pull-down menu, fisheye menu and grid menu were tested to compare the performance time, error rate, simplicity, usefulness, user friendliness, and overall user preference of each menu type. The grid menu was more efficient in selection speed than the pull-down and fisheye menus when the number of menu-items was 50 and 100. The time needed to choose a menu-item with a grid menu was less affected by the size of menu. The pull-down and the grid menus were considered to be more satisfactory, simple, user friendly, and useful than the fisheye menu. 42.3 percent of subjects indicated that the grid menu was their preferred selection tool among the menus. The grid menu is an efficient and robust alternative menu choice for small and middle size menu list. Further study is required to examine the possibility of grid menu on mobile devices.

• Proceedings of the Technology Innovation Conference
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• 1997.07a
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• pp.247-265
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• 1997

The objectives of not-for-profit organizations including government supported research institutes are, by definition, to achieve socially desired nonfinancial goals. Current reporting focuses on providing information to meet the needs of users. This information may be provided in the annual research report, financial report, and other reports. An objective of current reporting is to provide users with information that will assist them in evaluating the performance(efficiency and effectiveness) of reporting entity. The evaluation of R&D project's performance requires information not only about the acquition and use of resources, but also about the outputs and outcomes of R&D activities, This study aims to recommend that R&D Service Efforts and Accomplish- mints(SEA) reporting is useful for performance evaluation in national R&D programmes. To achieve this aims, I attempt to develop the R&D SEA measures with reference to the Concepts Statement No. 2 of the Governmental Accounting Standards Board. R&D SEA measures consist of five categories : (1) input measures, (2) outcome measures, (3) output measures, (4) re1a1e efforts to accomplishments, (5) explanatory information.

• Journal of the Korea Computer Industry Society
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• v.5 no.2
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• pp.325-330
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• 2004

The Big O notation of a sorting algorithm analysis is an asymptotic algorithm analysis which gives information of a rough mathematical function with an infinite increase of a sample size, without any specification of a probabilistic model. Hence. in an application with a limited finite number of data, it is necessary to test efficiencies of sorting algorithms. I estimated probabilistic models which analyze the number of exchanges varying input sizes to sort. The estimated models to explain the relationship of sorting efficiency on the sample size (N of the sample size and S of the number of exchange of elements) are S=0.9305 $N^{1.339}$ for Quick sort algorithm with O(nlogn) time complexity, and S=0.2232 $N^{2.0130}$ for Insertion sort algorithm with O( $n^2$) time complexity. Furthermore, there are strongly supports that more than 99% of the above relationship could be explained by the estimated models (p＜0.001). These findings suggest it is necessary to analyze sorting algorithm efficiency in applications with a finite number of data or a newly developed sorting algorithm.

• Journal of Digital Convergence
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• v.9 no.6
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• pp.295-311
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• 2011

The government is working out the development of a venture enterprise through a venture certification system. The broad effects of its policies are anticipated by the government and revealed in the 'The Survey on Actual Condition of Venture Enterprises 2010'. These benefits include the revitalization of start-up, promotion of technological innovation, progress in marketing ability, improvement in corporate image, financing and investment, and benefit from tax reduction & exemption. However, with the estimation of production function and sales function, which both uses capital and labor as a basic elements, it was found that only 'financing and ease of investment' produces a statistically significant effect on production and sales. An addition, this study looks into whether venture-supporting system are helpful to the eradication of technical inefficiency. The policies brought about positive changes in reduction of technical inefficiencies except with regard to the ease of start-up where it was found that an increase in inefficiencies was the result.

• Journal of the Korean GEO-environmental Society
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• v.9 no.2
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• pp.23-29
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• 2008

It has been mentioned that CSTR (Completely Stirred Tank Reactor) and UASB (Upflow Anaerobic Sludge Blanket) processes, the existing anaerobic processes, have problems in the treatment of highly concentrated particulate organic wastewater (HCPOW). Therefore, this paper discusses the treatment possibility of distillery wastewater which is a typical HCPOW using ADEPT (anaerobic Digestion Elutriated Phased Treatment) process. In the comparison of CSTR and ADEPT, ADEPT produced much higher gas than that of CSTR removing more organic matters and suspended solids in ADEPT process, ADEPT had no effect on the decrease in pH by volatile fatty acids and showed steady pH in spite of relatively short HRT. In the results of removal rate according to recycle ratios between 6Qin and 2Qin in ADEPT, 6Qin showed high removal rate during the operation time. Therefore it appears that ADEPT had an applicability for the treatment of distillery wastewater. ADEPT could be a economical process, due to the short HRT, the energy recovery by the methane production, and the utilization for carbon source of produced organic acid from the ADEPT-acid reactor.

• The KIPS Transactions:PartC
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• v.19C no.1
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• pp.9-18
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• 2012

In 2010, Pedro et al. proposed RFID distance bounding protocol based on WSBC cryptographic puzzle. This paper points out that Pedro et al.'s protocol not only is vulnerable to tag privacy invasion attack and location tracking attack because an attacker can easily obtain the secret key(ID) of a legal tag from the intercepted messages between the reader and the tag, but also requires heavy computation by performing symmetric key operations of the resource limited passive tag and many communication rounds between the reader and the tag. Moreover, to resolve the security weakness and the computation/communication efficiency problems, this paper also present a new RFID distance bounding protocol based on WSBC cryptographic puzzle that can provide strong security and high efficiency. As a result, the proposed protocol not only provides computational and communicational efficiency because it requires secure one-way hash function for the passive tag and it reduces communication rounds, but also provides strong security because both tag and reader use secure one-way hash function to protect their exchanging messages.

• Tunnel and Underground Space
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• v.32 no.4
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• pp.254-271
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• 2022

The performance of truck haulage operations in an underground mine was evaluated using the time usage model and key performance indicators (KPIs) proposed by Global Mining Guidelines Group (GMG). An underground mine that mainly produces iron and titanium iron was selected as a study area, and truck haulage data were collected using Bluetooth beacons and tablet PCs. The collected data were analyzed to identify unit operations, activities, events, and required time of truck haulage operations, and time categories were classified based on the time usage model. The performance of the haulage operations was evaluated using nine indicators in terms of availability, utilization, and effectiveness. As a result, in terms of availability, uptime was 33.9%, physical availability was 95.7%, and mechanical availability was 94.9%. In the case of utilization, use of availability was 83.1%, asset utilization was 28.1%, and operating and effective utilization were 79.6% and 77.7%, respectively. Also, in terms of efficiency, operating efficiency was high at 97.6%, and production effectiveness was found to be 49%.

• Review of KIISC
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• v.13 no.6
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• pp.1-5
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• 2003

IT 산업이 급속히 발전하면서 정보보호와 관련된 문제가 중요한 고려 사항으로 대두되고 있다. 이러한 문제 해결의 일환으로 정보보호제품에 대한 수요가 증가하고 있으며, 또한 이들 정보보호제품의 안전 $.$신뢰성이 중요한 이슈로 부각되고 있다. 정보보호제품에 대한 보안성 평가가 이미 시행되고 있지만, 보안성 평가에는 비교적 많은 시간이 소요되므로 개발자가 평가 과정을 거쳐 적시에 제품을 시장에 출시하는 데에는 어려움이 따른다. 본 고에서는 정보보호 제품 개발 프로세스를 공통평가기준에서 요구하는 수준으로 개선하도록 함으로써, 제품 평가 준비 및 평가에 소요되는 비용과 시간을 경감시키고 평가의 효율성을 향상시킬 수 있는 방안을 모색하여 보고자 한다.