• 전자공학회논문지
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• 제50권3호
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• pp.203-211
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• 2013

본 논문에서는 바닥작업용 서비스 로봇을 위한 두 팔 매니퓰레이터의 개발 및 제어에 관한 연구를 기술하였다. 6자유도의 매니퓰레이터를 설계하였으며, 그 중 5자유도 매니퓰레이터를 제작하였다. 제작된 매니퓰레이터의 순기구학과 역기구학을 해석하고 시뮬레이션을 수행하여 기구학을 검증하였다. 실제로 역기구학을 바탕으로 로봇 팔을 제작하여 제어하였다. 양팔의 동작 성능을 확인하기 위해 오른쪽 팔과 왼쪽 팔을 각각 따로 제어하여 서로 다른 경로를 추종하는 실험을 수행하였다. 실험결과를 통해 기구학 분석을 검증하였으며, 시스템의 동작 여부를 확인할 수 있었다.

• 한국자동차공학회논문집
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• 제13권4호
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• pp.97-104
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• 2005

Vision-based lane sensing systems require accurate and robust sensing performance in lane detection. Besides, there exists trade-off between the computational burden and processor cost, which should be considered for implementing the systems in passenger cars. In this paper, a stereo vision-based lane detection system is developed with considering sensor configuration aspects. An inverse perspective mapping method is formulated based on the relative correspondence between the left and right cameras so that the 3-dimensional road geometry can be reconstructed in a robust manner. A new monitoring model for estimating the road geometry parameters is constructed to reduce the number of the measured signals. The selection of the sensor configuration and specifications is investigated by utilizing the characteristics of standard highways. Based on the sensor configurations, it is shown that appropriate sensing region on the camera image coordinate can be determined. The proposed system is implemented on a passenger car and verified experimentally.

• KIEAE Journal
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• 제16권3호
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• pp.129-135
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• 2016

Purpose: Building figuration is imperative to perceive the its value, environmental clean status and form. Therefore, maintenance activities of the building exterior are required to keep the housing condition and value. Each household should pay the repair cost which is brought out in the future. For this repair cost, the estimation model would needed to forecast and provide the required cost. This study aimed at providing the estimation model of the repair cost, using the repair survey data between the 2011 and 2014 in Seoul. Method: For these, it took various estimation function of repair cost such as 1st function, inverse function and so on. These above functions would be applied into the building exterior and outdoor facilities which figure the building shape and characteristics. Result: Results of this study are shown ; First, among 11 estimation models, the power function has a better statistics and goodness-of-fit than any other models. Second, the estimation model with a variable of household has a pattern in upward to the right. On the contrary, the model with management area is little downward to the right. Both of them are depended on the estimated parameter of the power function and the parameter smaller than 1.

• 대한한방체열의학회지
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• 제1권1호
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• pp.13-19
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• 2002

Objectives : This study was performed to apply thermography as an method in diagnosis of hwabyung patients. We studied 11 Hwabyung patients who visited to chronic diseases center and circulatory oriental internal medicine of Kangnam oriental medicine hospital and 11 patients control group. Methods : Diagnosis of Hwabyung was based on the dignostic criteria of Hwabyung. The temperature was measured on Chonjung(CV17) Shimsu(B15), Kansu(B18), Kyonjong(G21) in each group. The ${\Delta}T$ was measured between Chonjung(CV17) and Chungjong(CV16), left and right Chungjong(CV16), Shimsu(B15), Kansu(B18), Kyonjong(G21) in each group. We compared the ${\Delta}T$ and DITI types between patients and control group. Results : The ${\Delta}T$ between left and right Chungjong(CV16), Shimsu(B15), Kansu(B18), Kyonjong(G21) were not statistically significant. But the ${\Delta}T$ between Chonjung(CV17) and Chungjong(CV16) was statistically significant(P<0.05) in each group. In control group, DITI type was straight 36%, diamond 27%, multiple small spot 18%, others 18%. In Hwabyung patients group, DITI type was inverse triangle 64%, multiple small spot 9.1%, round 9.1%. Conclusions : The ${\Delta}T$ between Chonjung(CV17) and Chungjong(CV16) and DITI type is considered useful diagnostic methods on Hwabyung patients.

• 충청수학회지
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• 제29권1호
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• pp.59-71
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• 2016

To obtain more accurate approximation of the true images in the deblurring problems, the weighted global generalized cross validation(GCV) function to the inverse problem with multiple right-hand sides is suggested as an efficient way to determine the regularization parameter. We analyze the experimental results for many test problems and was able to obtain the globally useful range of the weight when the preconditioned global conjugate gradient linear least squares(Gl-CGLS) method with the weighted global GCV function is applied.

• Corrosion Science and Technology
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• 제4권5호
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• pp.201-206
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• 2005

Starting with the meaning of the word quality, diverse concepts connoted by the term are examined. Instead of a bathtub curve, the desirable shape of a failure rate covering the entire life of a good product, which might be called hockey-stick line, is introduced. From the hockey-stick line and the definition of reliability, two measurements are extracted. The terms r-reliability (failure rate) and durability (product life) are explained. The conceptual analysis of failure mechanics explains that reliability technology pertains to design area. The desirable shape of hazard rate curve of electronic items, hockey-stick line, clarifies that Mean-Time-to-failure (MTTF) as the inverse of failure rate can be regarded a nominal life. And Bx life, different from MTTF, is explained. Reliability relationships between components and set products are explained. Reshaped definitions of r-reliability and durability are recommended. The procedure to improve reliability and the reasons for failing to identify failure mode are clarified in order to search right solutions. And generalized Life-Stress failure model is recommended for the calculation of acceleration factor.

• International Journal of Control, Automation, and Systems
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• 제5권2호
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• pp.218-222
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• 2007

This paper presents a new Perfect Tracking Control (PTC) scheme for linear systems with state constraint. The proposed controller increases the number of the steps on-line for perfect tracking to satisfy the given ellipsoid-type state constraint. The unavoidable step delay that we impose is minimized by solving LMI feasibility problems and the possible feedback information loss is avoided. The proposed schemes are easy to develop, theoretically simple and clear, and include the conventional PTC as its special case.

• 대한수학회보
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• 제31권2호
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• pp.187-192
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• 1994

The author extended the small properties of topological semilattices to that of regular semigroups [3]. In this paper, it could be shown that a semigroup S is almost regular if and only if over bar RL = over bar R.cap.L for every right ideal R and every left ideal L of S. Moreover, it has shown that the Bohr compactification of an almost regular semigroup is regular. Throughout, a semigroup will mean a topological semigroup which is a Hausdorff space together with a continuous associative multiplication. For a semigroup S, we denote E(S) by the set of all idempotents of S. An element x of a semigroup S is called regular if and only if x .mem. xSx. A semigroup S is termed regular if every element of S is regular. If x .mem. S is regular, then there exists an element y .mem S such that x xyx and y = yxy (y is called an inverse of x) If y is an inverse of x, then xy and yx are both idempotents but are not always equal. A semigroup S is termed recurrent( or almost pointwise periodic) at x .mem. S if and only if for any open set U about x, there is an integer p > 1 such that x$^{p}$ .mem.U.S is said to be recurrent (or almost periodic) if and only if S is recurrent at every x .mem. S. It is known that if x .mem. S is recurrent and .GAMMA.(x)=over bar {x,x$^{2}$,..,} is compact, then .GAMMA.(x) is a subgroup of S and hence x is a regular element of S.

• 한국전자통신학회논문지
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• 제6권2호
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• pp.171-179
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• 2011

블록 암호는 Feistel 구조와 SPN 구조로 나눌 수 있다. Feistel 구조는 암호 및 복호 알고리즘이 같은 구조이고, SPN 구조는 암호 및 복호 알고리즘이 다르다. SPN 구조에서의 암호 및 복호 라운드 함수는 키 합산층과 S-박스에 의하여 혼돈을 수행하는 치환층 및 확산층의 세 단계로 구성된다. AES, ARIA 등 많은 SPN 구조에서 8 비트 S-박스를 사용하므로 Square 공격, 부메랑 공격, 불능 차분 공격 등이 유효하다. 본 논문에서는 암호와 복호 과정이 동일한 SPN 구조 블록 암호 알고리즘을 제안한다. SPN 구조 전체를 짝수인 N 라운드로 구성하고 1 라운드부터 N/2 라운드까지는 정함수를 적용하고, (N/2)+1 라운드부터 N 라운드까지는 역함수를 적용한다. 또한 정함수단과 역함수단 사이에 대칭 블록을 구성하는 대칭단을 삽입한다. 대칭단은 간단한 비트 슬라이스 대합 S-박스로 구성한다. 비트 슬라이스 대합 S-박스는 Square 공격, 부메랑 공격, 불능 차분 공격 등의 공격을 어렵게 한다. 본 논문에서 제안한 SPN 블록 암호는 제한적 하드웨어 및 소프트웨어 환경인 스마트카드와 전자칩이 내장된 태그와 같은 RFID 환경에서 안전하고 효율적인 암호 시스템을 구성할 수 있다.

• 대한방사선기술학회지:방사선기술과학
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• 제34권3호
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• pp.183-188
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• 2011

거리 역자승 법칙에 관한 엑스선 감약의 정도를 파악하고 이를 산란선 발생에서 적용하여 방사선사의 피폭을 저감할 수 있는 공간을 찾도록 알아보고자 하였다. 관전류량 10 mAs, 관전압 60 kVp, 70 kVp, 81 kVp, 90 kVp, 각각의 거리 60 cm, 120 cm, 180 cm에서 1차 선량을 측정하고, 산란선은 관전류량 20 mAs, 관전압 70 kVp, phantom의 중심부로부터 전면과 후면으로 42.5 cm, 52.5 cm, 62.5 cm 떨어진 곳에서 음 양극(좌우측)으로 각각 10 cm씩 60 cm까지 측정하였고, 거리역자승법칙과 비교하기 위해 전 후방 각각 42.5 cm, 85 cm, 127.5 cm에서 산란선을 측정하였다. 1차선은 거리가 2배에서는 20.52 mR(27.20%), 28.58 mR(25.20%), 38.82 mR(26.32%), 48.20 mR(26.27%)로 감약되고 거리가 3배에서는 7.06 mR(8.91%), 9.90 mR(8.73%), 13.64 mR(9.25%), 16.60 mR(9.05%)로 감약되는 것을 알 수 있었고, 산란선은 전 후방 각각 거리가 2배에서는 0.15 mR(23.09%), 0.15 mR(22.08%) 3배에서는 0.07 mR(10.43%), 0.06 mR(8.83%)로 감약되었다. 산란선의 발생량이 평균적으로 3사분면이 적게 발생하기에 환자를 붙잡고 촬영할 시에는 3사분면의 피사체에서 가능하면 거리를 두고 환자를 잡는 것이 피폭선량을 줄일 수 있다.