• Journal of The Korean Association of Information Education
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• v.22 no.3
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• pp.297-305
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• 2018

Physical computing is the concept of expanding computing to humans, environments, and objects. It draws attention as a programming learning medium based on physical outputs in integration of hardware and software. This study developed a programming learning model based on interactive prototyping using the characteristics of physical computing with a high degree of technical freedom and analyzed its learning effect in an experiment. To examine the effect of the experimental treatment, this researcher divided fifty nine 5th-grade elementary students into an experimental group and into a control group. the interactive prototyping programming learning model was applied to the experimental group, and a linear sequential programming learning model was applied to the control group. Information Science Creative Personality Test was conducted before and after the experimental treatment. Analysis of Covariance was conducted with the pre-test scores of the two groups. As a result, it was proved that there was the effect of learning at the significance level of .05. It indicates that the physical computing based interactive prototyping programming learning model is applicable to the programming learning for 5th-grade elementary students.

• The Transactions of the Korea Information Processing Society
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• v.7 no.10
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• pp.3226-3235
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• 2000

The more complex and larger semiconductor integraed circuits become, the core important delay test becomes which guarantees that semiconductor integrated circuits operate in time. In this paper, we propose a new partial enhanced scan method that can generate test patterns for path delay faults offectively. We implemented a new partial enhanced scan method based on an automatic test pattern generator(ATPG) which uses implication and justification . First. we generate test patterns in the standard scan environment. And if test patterns are not generated regularly in the scan chain, we determine flip-flops which applied enhanced scan flip-flops using the information derived for running an automatic test pattern generator inthe circuti. Determming enhanced scan flip-flops are based on a fault coverage or a hardware overhead. through the expenment for JSCAS 89 benchmark sequential circuits, we compared the fault coverage in the standard scan enviroment and enhance scan environment, partial enhanced scan environment. And we proved the effectiveness of the new partial enhanced scan method by identifying a high fault coverage.

• Journal of KIISE:Computing Practices and Letters
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• v.8 no.3
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• pp.356-365
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• 2002

Test systems verify and classify the various kinds of semiconductor products. So test systems need programs that can test the various special functions of hardware modules and products. Programs can be modified, compiled and executed by engineers. Consequently, the systems needs programming languages that can be easily programmed by engineers and their compilers that can compile and execute teat programs. In this paper we discuss the environment of programming languages and their compilers for the existing domestic teat systems. We design a programming language and implement its compiler that can be conveniently used by the experienced engineers in the industry field. Experimental results show that a newly designed test system with our programming language and compiler can teat products faster than the existing test system.

• Journal of KIISE:Computer Systems and Theory
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• v.27 no.9
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• pp.803-815
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• 2000

최근 처리해야 하는 정보의 양의 급속히 배가됨에 따라 디스크 배열(disk array) 시스템에서 사용하는 디스크의 수가 증가되는 경향을 보이고 있다. 그러나 많은 수의 디스크를 이용하여 디스크 배열을 구성하게 되면 디스크 오류 발생 확률을 높이는 결과로 이어지게 된다. 이 논문에서는 많은 수의 디스크를 사용하는 환경에서도 높은 신뢰성을 제공하기 위하여 DH(Diagornal-Horizontal) 기법이라 불리는 두가지 형태의 이중 패리티 배치 기법들을 제안한다 제안한 기법들은 사선 패리티와 수평 패리티를 인코딩하여 이용함으로써 디스크 배열에서 이중 디스크 오류의 복구가 가능하다. DH 기법들의 특징은 알고리즘이 단순하고, N을 임의의 소수라고 할 때 N 또는 N+1개의 디스크를 기반으로 쉽게 구현할 수 있다. 기본적으로 제안하는 기법들은 검사정보 저장을 위해 최적의 디스크 공간을 사용하고, 인코딩이나 디코딩 과정에서 단지 XOR 연산만을 필요로 하기 때문에 하드웨어의 수정 없이 기존의 디스크 배열 시스템에 쉽게 응용할 수 있다. 더욱이 치명적 오류를 방지할 수 있는 두 오류 디스크에 대한 복구 시간은 디코딩에서의 XOR 연산수를 최소화함으로써 신속하게 처리할 수 있다. 결과적으로 제안하는 기법들은 디스크 배열 시스템에서의 치명적 오류 확률을 낮출 수 있는 효과적인 방법이다.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.14 no.7
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• pp.699-704
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• 2003

The characteristics of microwave reflectometry as a non-invasive device to examine the density distribution of inhomogeneous media using the technology of FM radar is presented. The microwave reflectometry system requires an optimized system hardware and the understanding of system response from the density distribution in order to provide the system solution to describe the object under test quantitatively. Among the applications, the use of microwave reflectomeoy in the area of applied plasma physics has been newly proposed and the number of usage is found to be increasing gradually. The microwave reflectometry systems that depend on the nature of the object under test are described. The experimental method to characterize the system is explained and the experimental results on the wavenumber dependence and the sensitivity on density perturbation are presented as well as the comparison to the results from the one dimensional numerical simulations.

• Proceedings of the Korean Information Science Society Conference
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• 2011.06c
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• pp.88-91
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• 2011

NAND 플래시 메모리는 저전력과 빠른 접근 속도의 특징 때문에 차세대 저장장치로 주목 받고 있다. 특히 플래시 메모리로 만들어진 SSD(solid state disk)는 인터페이스가 기존의 하드디스크와 동일하고 대용량화 되고 있기 때문에 가까운 미래에 다양한 저장시스템의 저장장치로 사용될 것으로 예상된다. 그러나 NAND 플래시메모리 기반 저장장치는 쓰기 전 소거 구조와 같은 독특한 하드웨어 특징을 가지고 있기 때문에 특정 지역에 반복적인 쓰기 요청을 발생하는 B트리를 구축하는 것은 심각한 성능저하를 야기 할 것이다. 이러한 문제를 해결하기 위해 버퍼를 이용하여 B트리 구축 성능을 개선한 방법들이 제안되었다. 그러나 이러한 기법들은 갑작스러운 전원 차단 시 버퍼에 유지하고 있던 데이터를 모두 유실하기 때문에 고장회복을 위한 추가적인 방법이 필요하다. 따라서 본 논문에서는 버퍼를 이용한 방법 중 IBSF기법을 기반으로 NAND 플래시 메모리 기반 저장장치에서 고성능의B트리 구축 방법뿐만 아니라 전원 차단시 효율적인 고장회복을 할 수 있는 기법을 제안한다. 본 논문에서 제안하는 기법은 B트리 변경시 변경 된 정보를 로그에 저장하여 관리한다. 또한 루트노드가 변경될 때 검사점(checkpoint)을 수행한다. 마지막으로 다양한 실험을 통하여 본 논문의 고장회복 성능을 보여준다.

• Journal of Biomedical Engineering Research
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• v.19 no.3
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• pp.261-268
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• 1998

Electrogastrography(EGG), the cutaneous recording of the myoelectrical activity of the stomach using surface electrodes, is a non-invasive technique to detect gastric motility disorder, We developed a detection and analysis system for the EGG signal, which consists of hardware(bio-amplifier, filter) and softwere(user interface, analysis algorithm, patient database). The EGG signal was amplified and filtered by 3 channel bio-amplifiers, and simultaneously digitized and stored on IBM PC with a sampling frequency of 16 Hz. The stored EGG signal was analyzed using developed algorithm to extract clinically useful information from the signal. The developed system has tested through animal experiments, and is under clinical evaluation.

• Proceedings of the Korea Information Processing Society Conference
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• 2020.11a
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• pp.8-11
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• 2020

4 차 산업혁명 시대의 도래와 함께 AI, ICT 기술의 융합이 진행됨에 따라, 유저 레벨의 디바이스에서도 AI 서비스의 요청이 실현되었다. 이미지 처리와 관련된 AI 서비스는 피사체 판별, 불량품 검사, 자율주행 등에 이용되고 있으며, 특히 Deep Convolutional Neural Network (DCNN)은 이미지의 특색을 파악하는 데 뛰어난 성능을 보여준다. 하지만, 이미지의 크기가 커지고, 신경망이 깊어짐에 따라 연산 처리에 있어 낮은 데이터 지역성과 빈번한 메모리 참조를 야기했다. 이에 따라, 기존의 계층적 시스템 구조는 DCNN 을 scalable 하고 빠르게 처리하는 데 한계를 보인다. 본 연구에서는 DCNN 의 scalable 하고 빠른 처리를 위해 3 차원 메모리 구조의 Processing-In-Memory (PIM) 가속기를 제안한다. 이를 위해 기존 3 차원 메모리인 Hybrid Memory Cube (HMC)에 하드웨어 및 소프트웨어 모듈을 추가로 구성하였다. 구체적으로, Processing Element (PE)간 데이터를 공유할 수 있는 공유 캐시 및 소프트웨어 스택, 파이프라인화된 곱셈기 및 듀얼 프리페치 버퍼를 구성하였다. 이를 유명 DCNN 알고리즘 LeNet, AlexNet, ZFNet, VGGNet, GoogleNet, RestNet 에 대해 성능 평가를 진행한 결과 기존 HMC 대비 40.3%의 속도 향상을 29.4%의 대역폭 향상을 보였다.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.46 no.12
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• pp.1049-1055
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• 2018

This paper proposes the Signal Quality Indicator (SQI) to certify the wired communication channels connected between sub-systems embedded in guided flight systems. The communication signals can be distorted due to the poor interconnections of wired channels, the interference from the signals passing through the adjacent routed channels, and additive white Gaussian noises. As the ways to find out the condition of the communication channels, we present the Hamming distance based SQI (H-SQI) and the Euclidean distance based SQI (E-SQI). Two SQIs are compared in terms of the SQI resolution performance and the required number of hardware resources for implementations. The E-SQI requires the 10 times FPGA resources and an additional analog-digital converter over the H-SQI in spite of its outstanding SQI resolution performance. Moreover, the H-SQI could have the enough SQI resolution performance to find out the channel condition by increasing the oversampling rate, so the H-SQI is the more adequate than the E-SQI for the SQI of the guided flight systems.

• Progress in Medical Physics
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• v.17 no.3
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• pp.144-152
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• 2006

The telemedicine using independent client-server system via networks can provide high quality normalized services to many hospitals, specifically to local/rural area hospitals. This will eventually lead to a decreased medical cost because the centralized institute can handle big computer hardware systems and complicated software systems efficiently and economically, Customized cancer radiation treatment planning for each patient Is very useful for both a patient and a doctor because it makes possible for the most effective treatment with the least possible dose to patient. Radiation planners know that too small a dose to the tumor can result in recurrence of the cancer, while too large a dose to healthy tissue can cause complications or even death. The best solution is to build an accurate planning simulation system to provide better treatment strategies based on each patient's computerized tomography (CT) image. We are developing a web-based and a network-based customized cancer radiation therapy simulation system consisting of four Important computer codes; a CT managing code for preparing the patients target data from their CT image files, a parallel Monte Carlo high-energy beam code (PMCEPT code) for calculating doses against the target generated from the patient CT image, a parallel linear programming code for optimizing the treatment plan, and scientific data visualization code for efficient pre/post evaluation of the results. The whole softwares will run on a high performance Beowulf PC cluster of about 100-200 CPUs. Efficient management of the hardware and software systems is not an easy task for a hospital. Therefore, we integrated our system into the client-sewer system via network or web and provide high quality normalized services to many hospitals. Seamless communication with doctors is maintained via messenger function of the server-client system.