Linear Combination Analysis Using GPS Data

Park, Woon-Yong,Lee, Dong-Rak,Back, Ki-Suk,Hong, Jung-Soo 東亞大學校 建設技術硏究所 2005 硏究論文集 Vol.28 No.2

We can process and compute the position, velocity and time by satellite signals of GPS. The signals are used to compute positioning of three dimensions and timing offset of the receiver clock when we can track the tour satellite signals at least. One of the specified aims is to use less expensive single frequency code/carrier phase GPS receivers, which are typically around half the price of dual frequency receivers. In the study, the author analyzed the accuracy and applicability of frequence linear combination using triangulation points evaluated distance limitation.

소프트 실시간 시스템의 주기변형에 의한 프로세스 스케줄링

崔龍洛,朴眞燮 大田大學校 1989 論文集 Vol.8 No.1

This paper studies on the period transformation algorithm. Rate monotonic algorithm was proved to be the optimal static priority scheduling algorithm for periodic process. Under dynamic environment, both earliest deadline and liast laxity scheduling algorithm were proven to be optimal dynamic priority scheduling algorithm. In spite of the optimality property, none of these algorithm are widely used in practice. But, by the period transformation on the basis rate monotonic algorithm, this problem was solved easily. Though this algorithm has low efficiency, simulation result was proven that nonperiodic deadline was guaranteed all.

인증 기능을 갖는 키 교환 알고리즘

최용락 大田大學校 産業技術硏究所 1997 산업기술연구소 論文集 Vol.8 No.1

This paper proposes a two pass and a three-pass authentication exchange schemes which combine public-key based on the mutual entity authentication with a Diffie-Hellman key derivation exchange. The security of key exchange of the proposed schemes depends on the discrete logarithm problem. The security of the entity authentication depends on that of the signature mechanism to be used in the proposed scheme. In comparison with the Kerberos, X.509 exchanges, and ISO 3-way authentication protocol, the proposed schemes ar not only simple and efficient, but also resistant to the full range of replay and interception attacks.

石炭灰를 利用한 燐의 除去에 관한 硏究

이강락,공성호,이상혁,김용수 漢陽大學校 環境科學硏究所 2001 環境科學論文集 Vol.22 No.-

질소와 인등의 영양물질은 폐쇄성 수역에서 부영양화의 원인이 되는 중요한 물질이다. 이중 인은 조류 성장의 제한물질로 알려지고 있으며, 이러한 인을 제거하기 위해 여러 가지 방법들이 많은 연구자들에 의해 연구되어 지고 있다. 석탄회에의한 인 제거효율은 높은 pH에서 석탄회 성분중 CaO함량에 따라 영향을 받으며, CaO함량이 높을수록 인 제거율이 높게 나타났다. SEM 분석결과 인은 칼슘과 반응하여 석탄회 표면에 결정으로 부착, 제거되었다. 석탄회에 의한 인 제거는 pH에 따라 메커니즘이 다른 것으로 나타났다. 이것은 석탄회 성분중 Ca^2+, Al^3+, Fe^3+가 인과 반응시 높은 pH에서는 Ca^2+와 반응하고 낮은 pH에서는 Al^3+, Fe^3+ 등과 반응하여 인 화합물을 생성하며, 이와 같은 현상은 pH에 따라 생성된 인 화합물의 용해도에 차이가 있기 때문이다. 흡착질의 농도변화에 따른 영향은 흡착질 농도가 높아질수록 제거효율은 감소하나 단위 흡착제 중량당 인 제거량은 증가하였다. 인 제거에서 방해이온의 영향은 SO₄^2-와 Cl^-의 영향은 크지 않았으나 CO₃^2-는 대단히 큰 영향을 미쳤다. In a closed water system, nutrients, such as nitrogen and phosphorus, bring about severe eutrophication. Phosphorus has been known to be a limiting reactant for the growth of algae. For the reason, how to remove phosphorus from water have been extensively studied. Dephosphorus-efficiency was influenced by the CaO content in the coal fly ash, and it became higher as the content increased. SEM analyses indicated that phosphorus was removed by the reaction between phosphorus and calcium, which generated a crystalline product on the surface of the coal fly ash. Dephosphorus reaction by coal fly ash followed different reaction mechanisms. This observation was resulted from different reaction mechanisms in different media. In basic media, phosphorus reacts mostly with Ca^2+, whereas it reacts with Al^3+ and Fe^3+ in acidic solution, thereby generates phosphorus compounds with different solubilities to the solution. As concentration of the adsorbent rised, the dephosphorus-efficiency was decreased, even though the amount of phosphorus removed per unit weight of the adsorbent was increased. As an interfering ion. CO^3- influenced dephosphorus reaction much, whereas SO₄^2- or Cl^- did not.

분산 시스템 환경의 인증 서비스 및 실체 인증 메커니즘 분석

최용락 大田大學校 産業技術硏究所 1996 산업기술연구소 論文集 Vol.7 No.2

A distributed system is susceptible to a variety of security threats mounted by intruders as well as legitimate users of the system. This paper deals with authentication services in a distributed system. By reviewing some basic authentication requirements and comparing several authentication schemes, we can make the consideration of main design issues for a complete cryptographic-based authentication mechanism. In this paper, the various types of masquerade and replay attacks among the communication entities are analyzed in the related authentication mechanism such as Kerberos, X.509, Difffie&Hellman, PGP and SPX.

이미지 처리기법을 이용한 스캐너 용지 이송정밀도에 관한 연구

정용락,김영태,장영배 금오공과대학교 2005 論文集 Vol.26 No.-

Two different types of paper feeding methods are widely used for modem printers and scanners. One of them is the flat-bed type, which utilizes a translating camera to scan the images on a stationary sheet. The other one is the sheetfed type, which requires continuous movement of the sheet. This study involves the precision of the paper feeding mechanism of the sheetfed type, which is known to be less precise. Test sheets were generated by printing straight lines in both machine and lateral directions, forming square patterns. The test sheets were. fed into the scanner, and the machine-direction line spacing of the scanned images was analyzed. It was determined that the paper speed momentarily changed three times: when the leading edge of paper contacted the guide plate, the moment the leading edge reached the pull roller, and the instant the trailing edge departed from the push roller. It appeared that the first two speed reductions were due to buckling of the sheet, while the last one was related to the loss of pushing force. For 0.1-mm-thick paper, the variation of sheet speed due to the loss of pushing force was approximately 50 percent of the average speed, while the effect of the impact at the leading edge was less significant. However, the trends reversed with thicker 0.35-mm paper. The momentary speed reduction of the thicker paper due to the impact at the leading edge was more prominent than that due to the loss of pushing force.

개방형 분산환경의 정보보호를 위한 범용 암호 서비스 모델

최용락 大田大學校 産業技術硏究所 1997 산업기술연구소 論文集 Vol.8 No.2

This paper analysis the design model of generic security services for application programmers in open distributed environment. The generic security service provides cryptographic interfaces to application programmers which don't have the knowledge of cryptographic algorithm in detail. In this paper, GSS-API, GCS-API and PKI that can be used in various application mechanisms are reviewed and the design strategies of a generic cryptographic service API are proposed.

범용 퍼지 신경회로망 응용 모델

김용수,최용락 대전대학교 산업기술연구소 1999 산업기술연구소 論文集 Vol.10 No.2

The performance of neural network depends on the structure, the similarity measure used, and the learning rule. This paper presents a fuzzy learning rule which incorporates fuzzy membership value and intra-cluster membership value into the leaky competitive learning rule. The proposed learning rule is compared with the Kohonen learning rule. The IRIS data set is used to analyze the effect of two learning rules on the performance of the neural network.

지붕경사각 변화에 따른 막구조의 풍압 변화 특성

길용식,김동우,하영철,이광렬,김종락 대한건축학회 2003 대한건축학회 학술발표대회 논문집 - 계획계/구조계 Vol.23 No.1(구조계)

This paper describes on the results of 1:400 geometrical laboratory modeling of wind-induced point pressure on the membrane roof structure of Stadium with variable roof slopes. The wind flow for flat ground surface was simulated in a boundary wind tunnel at Kumoh National Institute of Technology. The roof slope of membrane structure changed into 5 types. The locations of wind pressures taps are distributed on the same upper and lower part of membrane roof. The resultant wind pressure for each measurement points are analysed on 2 categories. One is acting on upper direction, the other is lower direction. The results showed that in the case of upper direction the changes of wind pressures on the membrane roof are not dominant in regard to changing roof slope, but in lower direction wind pressures are increased at the rear part of roof with changing roof slopes.

메세지 전송을 이용한 클럭 동기화에 관한 연구

최용락,박진섭,하수철 大田大學校 1988 論文集 Vol.7 No.1