• The KIPS Transactions:PartD
• /
• v.11D no.2
• /
• pp.351-360
• /
• 2004

Most mobile agents are migrated to many mobile agent systems by the sequential node migration method. However. in this case, if some problems such as host's fault or obstacle etc. happened, mobile agent falls infinity walt or orphan states. Therefore, it is difficult to get an expectation effect as use of other distribution technologies because the required time for networking between nodes increases. And so, many researches have been performed to solve this problems. However, most of methods decide node migration based on passive routing table or detour hosts which have some problems. Actually, the researches for reducing the total required time for networking are insufficient yet. In this paper, to reduce the required time for networking of mobile agent we design an active routing table based on the information of implemented objects which are registered in the meta-table of naming agent. And also, for user's keyword, we propose an replication model that replicates many agent object according to the information and number of object references corresponding to meta-table. Replicated objects are migrated to mobile agent systems in parallel and it provides minimized required time for networking.

• Journal of the Korean Society for Aeronautical & Space Sciences
• /
• v.47 no.5
• /
• pp.326-334
• /
• 2019

Development of Small UAV using HILS (Hardware In the Loop Simulation) can be effectively used to improve the reliability of UAV (Unmanned Aerial Vehicle) while reducing cost and time. It is also possible to reduce the damage to people or property by simulating the malfunction of the Flight Control Computer (FCC) that may occur during the actual flight. For applying such HILS, a real-time simulation environment capable of providing an environment similar to an actual flight condition is required. In this paper, we constructed a real - time HILS environment for Small UAV using 6 D.O.F motion table. In order to link the 6 D.O.F motion table developed in the previous research with the HILS environment in real time, the motion algorithm was changed from the position control method to the velocity control method. Also, we implemented modeling of inverse kinematics model for command transmission in Matlab $Simulink^{(R)}$ and verified the action of motion table according to the simulation model.

• Journal of the Korea Institute of Information Security & Cryptology
• /
• v.16 no.6
• /
• pp.95-109
• /
• 2006

Elliptic Curve Cryptosystem (ECC) is suitable for resource-constrained devices such as smartcards, and sensor motes because of its short key size. This paper presents an efficient multi-scalar multiplication algorithm which is the main component of the verification procedure in Elliptic Curve Digital Signature Algorithm (ECDSA). The proposed algorithm can make use of a precomputed table of variable size and provides an optimal efficiency for that precomputed table. Furthermore, the given scalar is receded on-the-fly so that it can be merged with the main multiplication procedure. This can achieve more savings on memory than other receding algorithms. Through experiments, we have found that the optimal sizes of precomputed tables are 7 and 15 when uP+vQ is computed for u, v of 163 bits and 233 bits integers. This is shown by comparing the computation time taken by the proposed algorithm and other existing algorithms.

• Journal of the Korea Institute of Information Security & Cryptology
• /
• v.22 no.3
• /
• pp.565-573
• /
• 2012

To investigate the business corruption, the obtainments of the business data such as personnel, manufacture, accounting and distribution etc., is absolutely necessary. Futhermore, the investigator should have the systematic extraction solution from the business data of the enterprise database, because most company manage each business data through the distributed database system, In the general business environment, the database exists in the system with upper layer application and big size file server. Besides, original resource data which input by user are distributed and stored in one or more table following the normalized rule. The earlier researches of the database structure analysis mainly handled the table relation for database's optimization and visualization. But, in the point of the digital forensic, the data, itself analysis is more important than the table relation. This paper suggests the extraction technique from the table relation which already defined in the database. Moreover, by the systematic analysis process based on the domain knowledge, analyzes the original business data structure stored in the database and proposes the solution to extract table which is related incident.

• The Korean Journal of Nuclear Medicine Technology
• /
• v.13 no.3
• /
• pp.86-91
• /
• 2009

Purpose: The whole body scan in Nuclear Medicine is a widely accepted examination and procedure. Especially, it is mainly used in bone, I-131, MIBI, and HMPAO WBC scans. The diverse uses of the whole body scan range from the HMPAO WBC scan with a speed of 13cm/min, to a whole body bone scan using the Onco. Flash technique with a speed of 30cm/min. The accuracy of table movement has a strong correlation with the image quality, and inaccuracy of speed could negatively affect the image quality. The purpose of this study is to evaluate the accuracy of the table movement while considering the influence of the age of the equipment and the variability in the weight of the patients. Material and Methods: The study was conducted using two of Seoul Asan Medical Center's SIEMENS gamma cameras which are commonly used in our whole body study. The first one is the oldest gamma camera, an ECAM plus (installed in 2000), and the last is brand new one, a SYMBIA T2 (installed in 2008). Three trials were conducted with the tables moving at a different speed each time; 10, 15 and 30 cm/min. The tables' speeds were measured by checking how long it took for the table to move 10cm, and this was repeated every 10cm until the table reached 100 cm. With an average body weight of the patients of about 60~70 kg, the table speed was measured with weights of 0 kg, 66 kg and 110 kg placed on the table, then compared among conditions. Results: The coefficient of variance (CV) of the ECAM plus showed 1.23, 1.42, 2.02 respectively when the table movement speeds were set at 10, 15, and 30 centimeters per minute. Under the same conditions, the SYMBIA T2 showed 1.23, 1.83 and 2.28 respectively. As table movement speed more, the variance of CV as the speed increases. When the patient body weight was set to 0, 66 and 110kg, the CV values of both cameras showed 0.96, 1.45, 2.08 (0 Kg), 1.32, 1.72, 2.27 (66 Kg) and 1.37, 1.73, 2.14 (110 Kg). There was no significant difference (p>0.05) in 95 percent of confidence intervals and measured CV values were acceptable. However, the CV value of the SYMBIA T2 was relatively larger than the ECAM plus. Conclusion: The scan speed of the whole body scan is predetermined based on which examination is being performed. It is possible for the accuracy of the speed to be affected, such as the age of the equipment, the state of the bearings or the weight of a patient. These factors can have a negative impact on the diagnostic consistency and the image quality. Therefore, periodic quality control should be needed on the gamma cameras currently being used, focusing on the table movement speed in order to maintain accuracy and reproducibility.

• Proceedings of the Korean Information Science Society Conference
• /
• 2004.10b
• /
• pp.607-609
• /
• 2004

질 높은 모바일 게임을 단시간에 개발하기 위해서 예전에 PC에서 인기 있었던 게임을 모바일용으로 재개발하는 경우가 많아지고 있다. 모바일의 플랫폼이 통일화되어 있지 않은 지금 PC의 게임을 모바일로 변환하는 작업을 플랫폼 별로 개별 개발을 하여야 하는 문제점을 갖고 있으며 이러한 중복되는 작업을 최소화하기 위해서 규정된 내용의 변환 테이블을 이용하여 자동으로 변환 작업이 가능하도록 하고자 한다. 아바타 변환기는 상의한 모바일 플랫폼에서 사용되는 프로그램 구조와 API로 구성된 변환 테이블을 가지며, 변환 테이블을 기준으로 변환하고자 하는 플랫폼에 동작하는 모바일 게임 프로그램을 재 생성해 낸다 이로 인하여 PC의 게임을 모바일 게임으로 변환하는 작업이 하나의 플랫폼으로 개발을 완료하면 다양한 플랫폼에서 서비스 가능하게 될 것이다

• Aerospace Engineering and Technology
• /
• v.13 no.2
• /
• pp.38-46
• /
• 2014

CRC (Cyclic Redundancy Codes) is a error detection method for the date transmission, which is applied to the GRDDP (GOES-R Reliable Data Delivery Protocol) between satellite and GEMS (Geostationary Environmental Monitoring Sensor) on the GEO-KOMPSAT 2B development. This paper introduces a principle of the table based CRC, and explains software implementation results of the CRC8 applied to GEMS.

• Proceedings of the IEEK Conference
• /
• 2003.07d
• /
• pp.1581-1584
• /
• 2003

Method which store to database from XML Document, especially related database, is general using extra middle-ware and using context mapping through parsing. It is seemed to most suitable method in an instant.

• Proceedings of the IEEK Conference
• /
• 2001.09a
• /
• pp.477-480
• /
• 2001

본 논문에서는 허프만 코딩의 기본 원리인 이진트리로부터 생성된 효율적인 일차원 검색테이블 구성과, 프로세싱 효율을 증가시키기 위한 수치연산 기법의 도입을 통하여 도출된 효율적인 허프만 디코딩 방법을 제시한다. 제안된 방법에서는 허프만 코드화 된 비트스트림으로부터 읽어 들인 비트 데이터를 직접 이진트리를 검색하기 위한 주소연산에 적용함으로써, 기존의 이진트리 검색을 위하여 수행되던 비교 및 분기문의 제거를 가능토록 하였다. 본 논문에서 제안하는 허프만 디코딩 기법은 기존의 비교 및 분기구분에 의하여 수행되던 허프만 디코딩 기법대비 30%이상의 검색속도 증가 및 이진트리 방식의 검색을 수행하기 위하여 필요로 하는 검색테이블에서 존재하던 데이터 및 노드간의 연결주소를 저장하기 위하여 사용되던 메모리 공간을 효율적으로 제거할 수 있는 일차원 검색테이블을 구성함으최써, 기존 방법대비 1/3의 메모리 공간만을 사용하도록 하였다. 제안된 허프만 디코딩 기법의 성능평가를 위하여 MPEG-2 AAC의 허프만 디코더에 적용한 결과 기존의 순차검색방법에 의한 디코딩 기법대비 198%의 성능향상 결과를 확인할 수 있었다.

• Proceedings of the IEEK Conference
• /
• 2000.09a
• /
• pp.341-344
• /
• 2000

본 논문에서는 복잡한 배경이나 조명 변화가 심한 영상에서도 피부영역을 정확하게 검출할 수 있는 피부영역 검출방법을 제안한다. 제안된 방법은 오프라인(off-line) 훈련과정과 온라인(on-line) 검출과정의 두 단계로 나누어진다. 훈련단계에서는 다양한 조명하에서 얻은 피부영상과 배경영상으로 구성된 훈련영상을 다차원의 열벡터로 표현하고 열벡터에 LDA(linear discriminant analysis)를 적용하여 선형변환된 특징벡터를 가지고 인덱싱 테이블을 생성한다. 검출단계에서는 카메라로 들어온 칼라영상을 여러 개의 조각영상으로 나누고 각각의 조각영상에 대하여 LDA를 적용하여 선형변환된 특징벡터를 구한다. 구해진 특징벡터를 미리 생성한 LDA 인덱싱 테이블에서 찾아 피부영역을 검출한다. 제안된 방법을 조명을 변화시킨 다양한 영상에 적용하여 실험한 결과 검출률이 상당히 우수함을 알 수 있었다.