• 디지털산업정보학회논문지
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• 제16권4호
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• pp.9-17
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• 2020

When IoT sensor nodes are deployed in areas where data collection is challenging, sensors must be relocated if sensing holes occur due to improper placement of sensors or energy depletion, and data collection is impossible. The sensing hole's cluster header transmits a request message for sensor relocation to an adjacent cluster header through a specific relay node. However, since a specific relay node is frequently used, a member sensor located in a specific cluster area adjacent to the sensing hole can continuously receive the movement message. In this paper, we propose a method that avoids the situation in which the sensing hole cluster header monopolizes a specific relay node and allows the cluster header to use multiple relay nodes fairly. Unlike the existing method in which the relay node immediately responds to the request of the header, the method proposed in this paper solves a ping-pong problem and a problem that the request message is concentrated on a specific relay node by applying a method of responding to the request of the header using a timer. OMNeT++ simulator was used to analyze the performance of the proposed method.

• 대한음성학회지:말소리
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• 제51호
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• pp.57-69
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• 2004

Comprehension monitoring is a process of message evaluation and a very important skill of communication. Comprehension monitoring is a necessary language skill in classroom, as it is important for children to assess their own understanding of task instructions and teaching content. The present study investigated comprehension monitoring skill of children with Specific Language Impairment(SLI) compared to age-matched children and language-matched children. 18 vignettes and 6 displays were constructed. Children were asked to choose one object or 'DK' card from a display after the children listened to the vignettes. The results showed that children with SLI didn't have problem in comprehending unambiguous utterance and using prior statement. However, they had problem in monitoring comprehending ambiguous utterance compared age-matched children. Their performance were similar to language matched younger children. With respect to their performance, several possible explanations were discussed.

• Management Science and Financial Engineering
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• 제11권1호
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• pp.25-48
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• 2005

Firms often collaborate on building an infrastructure, which benefits all the firms in the industry, although in unequal magnitudes. Then a difficult and tricky issue is concerned with 'free riding.' Should there be only 'common, i.e., industry-wide' benefits in such collaboration, the literature indicated that the free rider problem is unavoidable, In this paper, however, we suggest that while collaborating, the firm also learns firm-specific knowledge, experience, and know-how, which can be directly utilized for its own internal improvement. That is, the collaboration between firms provides them with not only 'industry-wide,' but also 'firm-specific' benefits, Our analysis shows that if there indeed exist two types of benefits simultaneously, depending on the balance between the two, the free rider problem can be mitigated or even eliminated.

• 한국정보통신학회:학술대회논문집
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• 한국해양정보통신학회 2005년도 춘계종합학술대회
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• pp.785-787
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• 2005

In the Bluetooth specification version 1.0, one specific frequency in one piconet was created depending upon the device clock and the Bluetooth native address at one specific time slot in the frequency hopping method. The basic hopping pattern was arranging the 79 ISM frequency band in pseudo-random fashion. Possible problem is the chance of collision of ownership of one specific frequency by more than 2 wireless devices when they are within the communication-active range. In this paper, we propose the adaptive frequency hopping method in order to resolve the possible problem so that more than 2 wireless devices communicates with their own client devices without being interfered. The proposed method was implemented with HDL later to be synthesized with an automatic EDA synthesizer and verified as well. The implemented adaptive frequency hopping circuit operated normally at 24MHz which will be the target clock frequency of the target Bluetooth device.

• 한국컴퓨터정보학회논문지
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• 제20권9호
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• pp.21-29
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• 2015

The set partitioning problem is a well-known NP-hard combinatorial optimization problem, and it is formulated as an integer programming model. This paper proposes an Integer Programming-based Local Search for solving the set partitioning problem. The key point is to solve the set partitioning problem as the set covering problem. First, an initial solution is generated by a simple heuristic for the set covering problem, and then the solution is set as the current solution. Next, the following process is repeated. The original set covering problem is reduced based on the current solution, and the reduced problem is solved by Integer Programming which includes a specific element in the objective function to derive the solution for the set partitioning problem. Experimental results on a set of OR-Library instances show that the proposed algorithm outperforms pure integer programming as well as the existing heuristic algorithms both in solution quality and time.

• 디지털산업정보학회논문지
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• 제6권4호
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• pp.161-170
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• 2010

This paper provides a novel approach for a user oriented system for face detection system for application developers. Even though there are many open source or commercial libraries to solve the problem of face detection, they are still hard to use because they require specific knowledge on detail algorithmic techniques. The purpose of this paper is to come up with a high-level system for face detection with which users can develop systems easily and even without specific knowledge on face detection theories and algorithms. Important conditions are firstly considered to categorize the large problem space of face detection. The conditions identified here are then represented as expressions so that application developers can use them to express various problems. Once the conditions are expressed by developers, the interpreter proposed take the role to interpret the conditions, find and organize the optimal algorithms to solve the represented problem with corresponding conditions. A proof-of-concept is implemented and some example problems are tested and analyzed to show the ease of use and usability.

• Journal of Information Processing Systems
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• 제8권4호
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• pp.567-574
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• 2012

This paper presents a strong designated verifiable signcryption scheme, in which a message is signcrypted by a signcryptor and only a specific receiver, who called a "designated verifier", verifies it using his own secret key. The scheme is secure, as an adversary can not verify the signature even if the secret key of the signer is compromised or leaked. The security of the proposed scheme lies in the complexity of solving two computationally hard problems, namely, the Discrete Logarithm Problem (DLP) and the Integer Factorization Problem (IFP). The security analysis of the scheme has been done and it is proved that, the proposed scheme can withstand an adaptive chosen ciphertext attack. This scheme can be very useful in organizations where there is a need to send confidential documents to a specific recipient. This scheme can also be applicable to real life scenarios, such as, e-commerce applications, e-banking and e-voting.

• Journal of the Korean Society for Industrial and Applied Mathematics
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• 제4권2호
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• pp.99-110
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• 2000

This paper is devoted to the parallelism of a numerical matrix eigenvalue problem. The eigenproblem arises in a variety of applications, including engineering, statistics, and economics. Especially we try to approach the industrial techniques from mathematical modeling. This paper has developed a parallel algorithm to find all eigenvalues. It is contributed to solve a specific practical problem, a vibration problem in the industry. Also we compare the runtime between the serial algorithm and the parallel algorithm for the given problems.

• 공학교육연구
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• 제18권3호
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• pp.39-45
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• 2015

Many methods have been suggested for a creative problem solving approach. TRIZ approach is ranked top in its practical application because it is originated from the real patent analysis. This approach is assumed to be generic which can be applied to any types of problems regardless of problem type and its domain. The objective of this study is to propose a creative problem solving approach using TRIZ's contradiction analysis, then introduce a case study of applying this approach to a creative design coursework. Main topic covers a creative problem solving approach, a problem definition using TRIZ contradiction analysis, finding invention principles, and problem solving from the generic approach. For the course project, Roborobo tool is adopted to implement the design concept. This coursework helps students finding a general problem solving approach, and applying a generic solution for their specific problem domain.

• 한국수학교육학회지시리즈A:수학교육
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• 제47권2호
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• pp.113-133
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• 2008

This study is to develop the methods of specifying teaching that can consider individual differences in middle school geometry education. The purpose of this study is to decide the variations causing individual differences and to find the proper learning methods considering the variations. Through literature review, this study made it clear that the matter of individual difference is just the matter of talent and examined what factors make up mathematical talents. On the basis of the result, five important variations and fourteen subordinate factors were determined. I researched into the learning methods that consider the determined subordinate factors using the 'congruence' unit of middle school textbooks and developed specific learning methods for each of the subordinate factors through specific congruence problem solving situations. This study can be summarized as follows : I researched the studies of mathematical ability conducted by several educators and psychologists. This research is divided into the early study and the developed study of mathematical ability. Through this study five specific variations were determined. And fourteen subordinate factors have been made from the determined variations. The specific learning methods based on individual differences was developed according to the fourteen subordinate factors on the basis of middle school textbooks of Korea, Gusev's textbook, problem books of Russia, and etc.