• 전자공학회논문지B
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• 제32B권3호
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• pp.31-37
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• 1995

In this paper, we propose a programmable 16 bit DSP architecture using FIFO instruction memory. With this DSP architecture, System structure, BUS structure, instruction set ant and an assembler for system test are developed. The characteristic of this structure is that it simply fetches instructions not from RAM but from FIFO using shift operations. Accordingly, System can be designed regardless of RAM access time. One cycle is enough to execute an instruction, if instruction pipeline is operated. Another merit of this structure is that we can obtain the same effect as instruction pipelining without constructing a complex pipelined controller by decreasing the pipeline number.

• 소성∙가공
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• 제19권2호
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• pp.113-119
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• 2010

Hydroforming is the technology that utilizes hydraulic pressure to form tube or sheet materials into desired shapes inside die cavities. Tube hydroforming provides a number of advantages over the conventional stamping process, including fewer secondary operations, weight reduction, assembly simplification, adaptability to forming of complex structural components and improved structural strength. In many case, hydroformed parts have to be structurally joined at some point. Therefore it is useful if the hydroformed automotive parts can be given a localized attachment flange. In this study for the numerical process design FE analysis was performed with DYNAFORM 5.5. Die parting angle and circumferential expansion ratio was optimized. With optimized condition, bulge and hydroforming experiments to form flange were performed. Forming characteristic at various pressure conditions was analyzed and optimized internal pressure condition was evaluated. The results show that flanged parts can be successfully produced by tube hydroforming process.

• 한국수학교육학회지시리즈D:수학교육연구
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• 제19권2호
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• pp.89-100
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• 2015

The study investigated pre-service teachers' knowledge and computational skills by using Triangular Arithmagon. Participants included 90 pre-service teachers from two schools in the United States and Taiwan. The Triangular Arithmagons Test (TAT) was used to measure pre-service teachers' performance in whole number, fractions, and decimals operations (i.e., addition, subtraction, multiplication, and division), each of which included level-1 (basic) and level-2 (advanced) tests. MANOVA analysis was performed to compare the performance between teachers from the United States and Taiwan. Results indicated that overall, pre-service teachers in Taiwan outperformed those in the United States, especially on the advanced-level tests. Pre-service teachers in the United States were found to have poor ability of solving complex operation problems. Different curriculum plans and teaching methods may lead to the performance gap between the two countries.

• 경영과학
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• 제18권2호
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• pp.25-38
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• 2001

The well-known back-propagation algorithm for multi-layered neural network has successfully been applied to pattern c1assification problems with remarkable flexibility. Recently. the multi-layered neural network is used as a powerful data mining tool. Nevertheless, in many cases with complex boundary of classification, the successful learning is not guaranteed and the problems of long learning time and local minimum attraction restrict the field application. In this paper, an Improved learning procedure of multi-layered neural network is proposed. The procedure is based on the generalized delta rule but it is particular in the point that the architecture of network is not fixed but enlarged during learning. That is, the number of hidden nodes or hidden layers are increased to help finding the classification boundary and such procedure is controlled by entropy evaluation. The learning speed and the pattern classification performance are analyzed and compared with the back-propagation algorithm.

• Journal of Chest Surgery
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• 제24권11호
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• pp.1045-1057
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• 1991

Over the past four decades after World War II a great deal of data and clinical experiences have been accumulated relating to the diagnosis and surgical treatment of cardiovascular diseases in Korea. Clinical data after the first open heart surgery by Professor Yung Kyoon Lee on August 7, 1959 up to 1984 revealed the total number of cardiovascular surgery in Korea as 13,100 cases performed in 22 institutes with overall hospital mortality of 7.7%[Cardiovascular Surgery in Korea 1985], Publishing committee of the Korean Thoracic and Cardiovascular Surgical Society collected the data of cardiovascular surgical cases in Korea again in between 1985 and 1990 from 38 institutes out of total 42 institutes of open heart centers in Korea. The results are: 1. The survey reply ratio was 90.5%[38 out of 42 institutes]. 2. Of the total 30,061 cases of cardiovascular surgery reported from 38 institutes 1,402 cases were failed as hospital mortality of 4.7%[4.5% of the 21,761 operations for congenital, and 5.2% of the 8,300 operations for acquired heart diseases]. Out of the total congenital cases, 17,303 cases were acyanotic group with a operative mortality as 2.0%, and 4,458 cases were cyanotic group with a hospital mortality as 14.le The incidence of corrective operations for complex congenital cardiac anomalies were increasing recently with decreasing age group. 3. During the year in 1990, 38 institutes performed 5,427 cardiovascular surgery with a hospital mortality of 3.4%. 4. Of the total cumulative 6,458 cases for cardiac valve surgery more than 90% cases were put to prosthetic valve replacement with hospital mortality as 4.8%. And the incidence of re-Do valve surgery was increasing recently as 13.1% in 1990. 5. Coronary artery bypass graft was increasing recently with 7.9% of hospital mortality in total 440 cases. Intracardiac operation for intractable arrhythmia was started since 1987 as 49 cases in total. Experiences on VAD and ECMO were also reported sporadically in recent year. 6. Home made oxygenator[OXYREX] is now in clinical use, and under animal experiment for clinical trial in near future.

• 센서학회지
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• 제19권2호
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• pp.99-111
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• 2010

This paper proposes an efficient hardware architecture to estimate disparities between 2D images for generating 3D depth images in a stereo vision system. Stereo matching methods are classified into global and local methods. The local matching method uses the cost functions based on pixel windows such as SAD(sum of absolute difference), SSD(sum of squared difference) and NCC(normalized cross correlation). The NCC-based cost function is less susceptible to differences in noise and lighting condition between left and right images than the subtraction-based functions such as SAD and SSD, and for this reason, the NCC is preferred to the other functions. However, software-based implementations are not adequate for the NCC-based real-time stereo matching, due to its numerous complex operations. Therefore, we propose a fast pipelined hardware architecture suitable for real-time operations of the NCC function. By adopting a block-based box-filtering scheme to perform NCC operations in parallel, the proposed architecture improves processing speed compared with the previous researches. In this architecture, it takes almost the same number of cycles to process all the pixels, irrespective of the window size. Also, the simulation results show that its disparity estimation has low error rate.

• 한국전자거래학회지
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• 제9권1호
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• pp.209-220
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• 2004

If protocol has fast operations and short key length, it can be efficient user authentication protocol. Lenstra and Verheul proposed XTR. XTR have short key length and fast computing speed. Therefore, this can be used usefully in complex arithmetic. In this paper, to design efficient user authentication protocol we used a subgroup of Galois Field to problem domain. Proposed protocol does not use GF(p/sup 6/) that is existent finite field, and uses GF(p²) that is subgroup and solves problem. XTR-ElGamal based user authentication protocol reduced bit number that is required when exchange key by doing with upside. Also, proposed protocol provided easy calculation and execution by reducing required overhead when calculate. In this paper, we designed authentication protocol with y/sub i/ = g/sup b.p/sup 2(i-1)//ㆍv mol q, 1(equation omitted) 3 that is required to do user authentication.

• 한국콘텐츠학회:학술대회논문집
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• 한국콘텐츠학회 2007년도 추계 종합학술대회 논문집
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• pp.84-88
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• 2007

데이터베이스관리시스템(DBMS)이 대용량의 트리플 형식의 지식을 저장하기 위한 도구로 사용되는 것이 일반적인 추세인 상황에서, 보다 효율적으로 트리플 형식의 지식을 저장/관리/추론/질의하기 위해 DBMS에 어떠한 형태로 스키마를 설계하느냐는 여전히 이슈로 남아 있다. 본 논문에서는 효율적인 질의 관점에서 확장 클래스-속성 뷰(ECPV)를 활용하여 질의를 처리하는 방법과 이로 인해 얻어지는 응답 속도의 개선을 소개한다. DBMS기반의 추론 엔진의 응답 시간은 결국 테이블의 크기와 조인 횟수에 비례하게 되며, 질의가 복잡할수록 필요한 조인 횟수도 늘어나므로 응답 시간도 증가하게 된다. ECPV는 바로 조인 횟수를 줄이기 위해 미리 조인 연산을 수행해 둔 것으로, 질의 과정에서 이를 활용하기 위해서는 SPARQL 질의를 ECPV를 사용하는 SQL 질의로 변환해줘야 한다. 본 논문은 이러한 변환 과정과 함께 실험을 통해 응답 속도의 개선 정도를 제시한다.

• 한국구조물진단유지관리공학회 논문집
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• 제1권2호
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• pp.87-94
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• 1997

This research aims to develop an algorithm of optimal transducer placement using Kinetic Energy of the structural system. The structural vibration response-based health monitoring is considered one of the best for the system which requires a long-term, continuous monitoring. In its experimental modal testing, however, it is difficult to decide on the measurement locations and their number, especially for complex structures, which have a major influence on the quality of the results. In order to minimize the number of sensing operations and optimize the transducer location while maximizing the accuracy of results, this paper discusses about an optimum transducer placement criterion suitable for the identification of structural damage. As a criterion algorithm, it proposes the Kinetic Energy Optimization Technique (EOT), and then addresses the numerical issues which are subsequently applicable to actual experiment where a bridge model is used. By using the experimental data, it compares the EOT with the EIM (Effective Independence Method) which is generally used to optimize the transducer placement for the damage identification and control purposes. The comparison conclusively shows that the EOT algorithm proposed in this paper is preferable when a structure is to be instrumented with fewer sensors.

• 한국가스학회지
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• 제20권2호
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• pp.66-71
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• 2016

현재 산업단지에는 수많은 센서로부터 얻는 정보를 이용해 누출 발생지역을 감지 감시하고 있다. 그러나 화학물질 누출사고는 꾸준히 발생하고 있으며, 때에 따라 다량의 화학물질이 누출되는 경우에는 큰 피해가 발생하고 있다. 이때 중요하게 작용하는 센서 배치가 현재까지는 과거의 경험을 통하여 그 결정이 이루어지거나, 또는 센서제작 업체에서 제시하는 가이드를 통하여 설치되고 있다. 따라서 본 연구에서는 화학물질 누출이 일어났을 때 빠른 감지 및 대응을 위해 가장 중요한 요소인 센서 배치 최적화 방법론을 제시하였다. 특히 공정구조에 따른 누출흐름이 미반영된 상태에서 초기 배치 최적화를 위해 센서 개수 최소화 측면과 화학물질감지확률 측면으로 나누어 일반적으로 사용할 수 있는 수식을 제시하였다. 제시된 방법은 간단한 누출 시나리오를 이용하여 검증을 진행하였고, 이를 통해 각 공정의 안전성 목표치를 성취함으로써 안전한 공정 운영이 가능하도록 하였다.