• Journal of Communications and Networks
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• v.18 no.1
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• pp.50-64
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• 2016

Nowadays, smart meter (SM) technology is widely effectively used. In addition, power allocation (PA) and channel selection (CS) are considered problems with many proposed approaches. In this paper, we will suggest a specific scenario for an SM configuration system and show how to solve the optimization problem for transmission between SMs and the data concentrator unit (DCU), the center that collects the data from several SMs, via simulation. An efficient CS with PA scheme is proposed in the TV white space system, which uses the TV band spectrum. On the basic of the optimal configuration requirements, SMs can have a transmission schedule and channel selection to obtain the optimal efficiency of using spectrum resources when transmitting data to the DCU. The optimal goals discussed in this paper are the maximum capacity or maximum channel efficiency and the maximum allowable power of the SMs used to satisfy the quality of service without harm to another wireless system. In addition, minimization of the interference to the digital television system and other SMs is also important and needs to be considered when the solving coexistence scenario. Further, we propose a process that performs an interference analysis scheme by using the spectrum engineering advanced Monte Carlo analysis tool (SEAMCAT), which is an integrated software tool based on a Monte-Carlo simulation method. Briefly, the process is as follows: The optimization process implemented by genetic evolution optimization engines, i.e., a genetic algorithm, will calculate the best configuration for the SM system on the basis of the interference limitation for each SM by SEAMCAT in a specific configuration, which reaches the solution with the best defined optimal goal satisfaction.

• The Journal of the Korea institute of electronic communication sciences
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• v.13 no.4
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• pp.729-736
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• 2018

Due to the frequency offset, interchannel interference (ICI) is occurred in the received symbols of the orthogonal frequency division multiplexing (OFDM) systems. The ICI self-cancellation (ICI-SC) technique appropriately adjusts the subchannel signal assignment of the OFDM symbols, thereby canceling the interference caused by other subchannels. The conventional adjacent symbol repetition (ASR) method can reduce the interference caused by remote subchannels. However, it may not mitigate or even increases the ICI produced by some nearest subchannels. To solve the problem, a new ASR based ICI-SC technique is proposed and its performance is analyzed in this paper. Here, a t-parameter obtained by the interference coefficients of 3 successive subchannels is applied. As a result, the proposed method has the same capability to reduce the influence of remote subchannels. However, it can reduce the ICI caused by the nearest subchannels significantly.

• Journal of Physiology & Pathology in Korean Medicine
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• v.26 no.6
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• pp.812-817
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• 2012

In "The region of the body in which abdomen pain manifests(腹痛有部分)" of "Dongeuibogam(東醫寶鑑)", the abdomen is divided into the upper abdomen(大腹), umbilicus area(臍腹) and lower abdomen(小腹), which are in turn assigned to 3 Yins of greater yin(太陰), lesser yin(少陰) and reverting yin(厥陰) respectively to explain the causes and treatments of abdomen pain according to their locations. Meanwhile, the present Korean medicine tends to issue herbal formula without considering the cause of regional abdomen pain and the aspect of cold and heat(寒熱), deficiency and excess(虛實) in the symptom. This fragmentary treatment may bring out a serious failure. For the correction of this problem, the literature study on "The region of the body in which abdomen pain manifests(腹痛有部 分)" of "Dongeuibogam(東醫寶鑑)" was carried out to obtain the following conclusions. In "The region of the body in which abdomen pain manifest (腹痛有部分)" of "Dongeuibogam(東醫寶鑑)", it turned out that the use of herbal formula for the abdomen pain was the integrated one of herbal formulas for the abdomen pain in the external contraction such as cold damage yin condition(傷寒陰證) and cold in the middle condition(中寒證) and that the cause of abdomen pain was the explanation of diverse internal causes for the abdomen pain. And it was also found that the assignment of the upper abdomen(大腹), umbilicus area(臍腹) and lower abdomen(小腹) to 3 Yins had the locational and meridian meanings of 3 Yins according to internal causes and external contraction to get the basis of abdomen pain treatment in dividing it into 3 Yins.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.41 no.10
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• pp.1210-1220
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• 2016

As modern warfare has changed into network centered, the ability to share situational awareness among allies become a core competency for performing operational missions. In an airborne environment, it uses a tactical data link such as Link-16 for shared situational awareness. There exist problems when it shares situational awareness over the existing data link that can not allocate slots dynamically or that can not change the number of a slot to be allocated. In addition, there was a problem that can not share this failure so that failed to improves situation awareness because of finite time slot resources. In this paper, we accommodate dynamic slot allocation and changes of slot allocation with mixed structure of TDMA (time division multiple access) and random access. We propose a technique that can be used when available slots are exhausted, and a load balancing method to prevent slot allocation delay when slot requesting or message sending is concentrated on a single subframe.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.17 no.5
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• pp.1160-1167
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• 2013

Web based simulation service is utilized to computationally analyze various phenomena in real world according to the progress of network and computing technology. In this paper, we present an improvement and utilization of e-AIRS (e-Science Aerospace Integrated Research System). e-AIRS, has been utilized to support web based CFD simulation service since 2008. has some problems such as stable system, pre processing, post processing. To solver this problem, we improved e-AIRS such as distributed service processing, personal simulation job assignment control, and faster data loading. After improvement, although users increase from 110 to 606, the priority of user requirements is changed from stable system to pre/post processor. User requirements and statistics about e-AIRS simulation service for each semester is analyzed to support more stable and comfortable service.

• Journal of Korean Society of Transportation
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• v.28 no.5
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• pp.131-139
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• 2010

The transport mode choice problem is to determine which of the alternative transport modes connecting an origin and destination will be used by a traveler. Most of the research relating to transport mode choice have mainly been focused on modeling, properties, and applications of the model, but rarely were concerned with equilibrium among the modes. This paper proves the equilibrium among the modes by using a logit mode choice model, and then verifies it with the Korean Transport Database (KTDB). In order to obtain such an equilibrium, this paper also presents a solution algorithm based on the fixed point theorem. The algorithm was tested with an example and confirmed the equilibrium solution.

• Journal of Korea Society of Industrial Information Systems
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• v.11 no.2
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• pp.18-28
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• 2006

We consider a Direct Input Output Manufacturing System(DIOMS) which has a munber of machine centers placed along a built-in Automated Storage/Retrieval System(AS/RS). The Storage/Retrieval (S/R) machine handles parts placed on pallets for the operational aspect of DIOMS and determines the optimal operating policy by combining computer simulation and genetic algorithm. The operational problem includes: input sequencing control, dispatching rule of the S/R machine, machine center-based part type selection rule, and storage assignment policy. For each operating policy, several different policies are considered based on the known research results. In this paper, using the computer simulation and genetic algorithm we suggest a method which gives the optimal configuration of operating policies within reasonable computation time.

• Convergence Security Journal
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• v.18 no.2
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• pp.123-131
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• 2018

The goal of this study is to look deeper into a reading education method for improving cognitive abilities of petty officer majoring students in community college level. Lack of the cognitive ability through the passing status of reading information processing highly can cause a problem for understanding information of context. Therefore, this study redefines the reading step to improve the cognitive ability. also, it sets up progress steps; material selection - learning - inspection - practice based on the cognitive abilities. To achieve those goals, there are two major ways. The first, setting up a proper reading assignment that is suitable for petty officer major students in community college level is a key step for this study. Second, the instructor leads the students to judge their own cognitive ability objectively by using a portfolio curriculum which contains a checking list of the portfolio, structuring a curriculum based on weekly achievements, self-checking, and setting up a direction of practice. The two presented ways are the most effective ways to develop students' cognitive ability based on continuous reading and checking. For the last, the study mentions a proposal for further tasks in this field of the study.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.43 no.4
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• pp.116-122
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• 2020

Human and material resource planning is one representative example of Operations Research. Resource planning is important not only in civilian settings but also in military ones. In the Air Force, flight scheduling is one of the primary issues that must be addressed by the personnel who are connected to flight missions. However, although the topic is of great importance, relatively few studies have attempted to resolve the problem on a scientific basis. Each flight squadron has its own scheduling officers who manually draw up the flight schedules each day. While mistakes may not occur while drafting schedules, officers may experience difficulties in systematically adjusting to them. To increase efficiency in this context, this study proposes a mathematical model based on a binary variable. This model automatically drafts flight schedules considering pilot's mission efficiency. Furthermore, it also recommends that schedules be drawn up monthly and updated weekly, rather than being drafted from scratch each day. This will enable easier control when taking the various relevant factors into account. The model incorporates several parameters, such as matching of the main pilots and co-pilots, turn around time, availability of pilots and aircraft, monthly requirements of each flight mission, and maximum/minimum number of sorties that would be flown per week. The optimal solution to this model demonstrated an average improvement of nearly 47% compared with other feasible solutions.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.15 no.6
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• pp.93-103
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• 2005

As the usage of XML documents increases the requirement of security for XML documents is growing. Especially it is very important to solve the problem of access control to XML object which shares in the environment where various users connect to each others. In this paper, we propose the access control model and mechanism which is combined with role hierarchy in the RBAC and hierarchical key derivation/assign method for the access to XML object. So we implement the access control mechanism by including hierarchical key derivation method. The technique, we proposed, gives not only the benefit in management which RBAC provides in access control to XML objects, but also it ran help derive a lower layer key from the higher layer user's. This feature decrease the number of keys managed in each role hierarchy in comparison with previous methods.