• Journal of Elementary Mathematics Education in Korea
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• v.16 no.1
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• pp.125-143
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• 2012

This study is designed to see the characteristics of elementary students' arithmetic error patterns and error rates by going up grades and to draw some implications for effective instruction. For this, 580 elementary students of grade 3-6 are tested with the same subtraction, multiplication and division problems. Their errors are analyzed by the frame of arithmetic error types this study sets. As a result of analysis, it turns out that the children's performance in arithmetic get well as their grades go up and the first learning year of any kind of arithmetic procedures has the largest improvement in arithmetic performance. It is concluded that some arithmetic errors need teachers' caution, but we fortunately find that children's errors are not so seriously systematic and sticky that they can be easily corrected by proper intervention. Finally, several instructional strategies for arithmetic procedures are suggested.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.17 no.1
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• pp.183-189
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• 2013

This paper proposes a novel lossless image compression scheme composed of direction-adaptive prediction and context-based entropy coding. In the prediction stage, we analyze the directional property with respect to the current coding pixel and select an appropriate prediction pixel. In order to further reduce the prediction error, we propose a prediction error compensation technique based on the context model defined by the activities and directional properties of neighboring pixels. The proposed scheme applies a context-based Golomb-Rice coding as the entropy coding since the coding efficiency can be improved by using the conditional entropy from the viewpoint of the information theory. Experimental results indicate that the proposed lossless image compression scheme outperforms the low complexity and high efficient JPEG-LS in terms of the coding efficiency by 1.3% on average for various test images, specifically for the images with a remarkable direction the proposed scheme shows better results.

• Journal of KIISE:Computer Systems and Theory
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• v.30 no.7_8
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• pp.352-358
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• 2003

A cluster of servers is the most promising solution to provide highly scalable and highly available network services with low implementation cost. One of popular solutions is using dispatcher as a request distributor. However this solution has the problem that is can be the bottleneck or single-point of failure point of itself. ONE-IP, the previous work, solves this serious problem by using broadcast message for distributing the request packet in LAN. Using simple scheduling technique, in addition, the overhead due to dispatching the request becomes minimal. However, as ONE-IP using very simple static scheduling algorithm, it would spread the request among servers unevenly and downgrades the cluster performance consequently. In this paper, we propose an improved TCP connection scheduling technique solving this unbalanced distributing problem. Using Round-Robin(RR) scheduling instead of hashing clients IP address, proposed technique can more evenly distribute incoming service requests among the servers. Experiments show average 3.8% improved performance in throughput compared to original ONE-IP technique.

• Journal of Digital Convergence
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• v.19 no.10
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• pp.105-110
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• 2021

The pig ICT automatic feeder is capable of automatically feeding feed, etc. according to the set conditions. However, there is a disadvantage that the setting condition itself must depend on the user's experience. Therefore, trial and error is caused, and there is a problem that the efficiency is lowered. Therefore, it is necessary to develop a system and implement a service model that can improve pig productivity by suggesting optimal feeding setting conditions based on data. Therefore, in this paper, a pig feeding management service model was developed using the performance analysis program such as the existing feeding data, breeding management data, and pig production management system. Through this, we developed a consumer-oriented feed management service model that can be efficiently utilized by analyzing pig data. In addition, it is possible to provide a service that contributes to a decrease in the mortality rate and an increase in the MSY of the farms with the intelligent automatic feeding management service, thereby improving the productivity of the pig farms and thereby increasing the income of the pig farms.

• Asia-pacific Journal of Multimedia Services Convergent with Art, Humanities, and Sociology
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• v.9 no.3
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• pp.747-756
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• 2019

Students studying interpretation perform additional study and training in addition to regular class. In simultaneous interpreting and consecutive interpreting, interpreter should memorize speaker's announcement because of different language structure. To improve short-term memory, students perform memory training that requires a pair of students. Therefore, they can not perform self-learning, and therefore, efficiency of studying decreases. To resolve this problem, computer based short-term memory training system has been proposed. Student can perform self-learning by changing words in text to special character in the training system. However, efficiency of studying decreases because computer has low portability. Since the number of words is larger than the number of words to be switched into special character, learning difficulty decreases. To resolve this problem, smart device based short-term memory training system has been proposed. Student can perform smart device based training system without space constraints. Since the proposed training system increases the number of words to be changed into special character, learning difficulty increases. We implemented and evaluated the functionalities of the proposed training system.

• Food Science and Industry
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• v.54 no.2
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• pp.73-81
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• 2021

Korea Agency of HACCP Accreditation and Services(KAHAS) has been focused on strengthen food safety management and competitiveness of the food industry. As a solution, the institution has launched the smart HACCP project, which is highly praised to be an innovation in food safety management system. KAHAS try to analysis of food manufacturing company, candidate of supporting about construction of smart factory from Small and Medium venture Business Department and confirm the effect of smart HACCP introduction. Korea Agency of HACCP Accreditation and Services will use these results for widespread of smart HACCP

• The Journal of Korean Institute of Communications and Information Sciences
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• v.27 no.9C
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• pp.853-860
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• 2002

In this paper, we proposed a new buffer management and cell scheduling scheme for GFR service in ATM networks. The proposed scheme is able to satisfy fairness criteria and efficient cell service in GFR. Performance analysis through the simulation presents that the proposed scheme can meet fairness 2(MCR plus equal share), which are not met by conventional scheduling mechanisms such as WRR. Also, the proposed scheme is superior to WRR about 29% in throughput and more efficency in fairness criteria.

• Proceedings of the Korean Information Science Society Conference
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• 2012.06a
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• pp.45-47
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• 2012

응용 프로그램의 QoS를 보장하기 위하여 태스크들에게 지분을 부여하고 단위 시간동안 각 태스크에게 주어진 지분만큼의 CPU 자원을 할당하는 비례 지분 알고리즘들이 많이 연구되었다. 대부분 비례 지분 알고리즘들은 태스크 수, 지분 분포 등의 다양한 환경에 따라 동작 방식이 다르기 때문에 이러한 인자들은 시스템의 공정한 자원 할당에 많은 영향을 준다. 본 논문에서는 비례 지분 알고리즘을 동작 방식에 따라서 분류한 후, 태스크의 수와 더불어 지분의 편향성, 즉 지분 분포에 따라 QoS 공정성 결과를 분석한다. 분석결과, 비례 지분 알고리즘에서는 태스크의 수 뿐 만 아니라 지분의 분포 역시 QoS 공정성에 많은 영향을 주며, 각 환경에 따라 효율적인 최적의 알고리즘들이 존재함을 확인하였다. 제안된 분석 결과는 QoS를 지원하는 다양한 시스템에서 효율적인 비례 지분 알고리즘을 선택하여 시스템의 신뢰성을 향상시킬 수 있다.

• Proceedings of the Korea Multimedia Society Conference
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• 2001.11a
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• pp.105-110
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• 2001

차량이 증가함에 따라서 첨단 교통 시스템(intelligent Transportation System: ITS)은 교통의 효율성, 신뢰성, 안정성 향상에 중점을 두게되었다. 첨단 교통 시스템의 일부분인 운전자 도움 시스템(Advanced Drivers Assistance System)은 운전을 하고 있는 상황에서 도움을 주기 위한 체계이고, 전방의 장애물 검지는 운전자 도움 시스템에서 전방의 상황을 운전자에게 알려주기 위한 중요한 요소이다. 본 논문에서는 HSV 컬러모델을 이용하여 연속된 컬러 영상으로부터 도로상의 차선과 방향 표시자에 구애받지 않고 전방의 차량을 검출하는 방법을 제안한다. HSV 컬러 모텔에서 차량을 검출하기 위해서는 태도(Saturation)와 명도(Value)성분의 관계를 이용하여 차량 영역을 구하고, HSV성분과 위치 특징을 이용하여 이전 프레임의 차량인지 검증한다. 도로 영상에서 차량이 있는 경우 차량의 아래 부분에 그림자 영역이 존재한다는 점을 이용한다. 제안된 방식의 효과를 검증하기 위해 노트북 PC와 PC용 CCD 카메라로 도로에서의 영상을 촬영하고 차량검출알고리즘을 적용한 처리 시간, 정확도, 차량검지 등의 결과를 보인다.

• Review of KIISC
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• v.20 no.5
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• pp.48-55
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• 2010

최근 들어, 저탄소 녹색성장에 대한 관심이 높아지면서, 전력 시스템과 IT 기술의 융합이 주목받고 있다. 이에 각국 정부에서는 스마트 그리드 사업을 추진하고 있으며, 관련 연구도 활발히 진행되고 있다. 스마트 그리드는 기존의 전력시스템과 IT 기술을 융합한 차세대 지능형 전력시스템으로, 모든 전자 기기들을 네트워크에 연결하고 실시간으로 에너지 사용량을 수집하여 사용자 및 에너지공급업체에 제공한다. 이를 통해 사용자는 에너지 소비를 줄일 수 있으며, 공급업체는 에너지 공급 효율성을 극대화할 수 있다. 이러한 서비스를 제공하기 위해서는 전력을 사용하는 각 사업장 및 가정에 스마트미터라는 장치를 설치해야만 한다. 하지만 스마트미터는 일반적으로 건물 외부에 설치되기 때문에 물리적으로 많은 공격 위협에 노출되어 있다. 따라서 플랫폼 무결성 보장, 신뢰할 수 있는 데이터 암호화 안전한 키 저장 등을 위해 최근 스마트미터에 TPM을 도입하고자 하는 연구가 이루어지고 있다. 이에 본 논문에서는 TPM 지술 및 개발 현황을 살펴보고, TPM과 관련된 평가인증 제도를 비교 분석하고자 한다.