• Proceedings of the Korean Society of Computer Information Conference
• /
• 2012.01a
• /
• pp.49-50
• /
• 2012

본 논문에서는 다수의 소형 무인 항공기(UAV) 그룹이 이동 중 장애물을 만났을 때 장애물과의 충돌을 방지하는 효율적인 장애물 회피 정책을 제안한다. 이 정책은 무선 에드혹(moblie ad hoc) 네트워크를 기반으로 단순히 UAV 간의 충돌 회피 뿐만이 아니라 UAV 그룹이 이동하는 도중 장애물을 발견 하였을 경우 장애물을 효율적으로 회피하는 방법과 연결성이 손실되는 경우에 대처하는 방안도 고려하였다. 제안하는 정책은 UAV가 장애물을 포착 하였을 때 현재 이동 속도를 유지한 채 장애물을 기준으로 UAV 그룹을 2개의 그룹으로 분리하여 장애물을 회피 한 후 일정한 지점에서 모여 다시 각 UAV간의 연결성을 유지한 채 목표물을 향해 이동하는 정책을 제안한다.

• The Korean Journal of Mycology
• /
• v.36 no.2
• /
• pp.130-137
• /
• 2008

To distinct the commercial strains in Pleurotus spp., 81 strains in eight Pleurotus species were used. DNA fingerprinting using URP-PCR was conducted to determine the phylogenetic relationships among Pleurotus strains. DNA profiles of Pleurotus species obtained by twelve URP primers were analyzed for genetic similarity by NTSYS program. We could divide strains into ten clusters, in which three of them belong to P. ostreatus and the others to the different species, respectively. At the 76% similarity level, 70 P. ostreatus strains were distinguished into three clusters. Cluster I contained 35 strains and some of them showed almost 100% similarity, one strain closely related to Weonhyeong and six strains closely related to Wangheukpyeong. In cluster II, twenty-one out of 23 strains showed 100% to Suhan. Cluster III contained twelve strains, including six strains closely related to Chunchu-2. The results suggested that there are many same strains with different names in mushroom spawn market.

• Proceedings of the Materials Research Society of Korea Conference
• /
• 2003.03a
• /
• pp.143-143
• /
• 2003

현대 산업이 발전함에 따라 다양한 기기들의 초소형화가 급속히 진행되고 있다. 이러한 요구에 부응하기 위하여 미세구동소자(Microelectromechanical system)의 개발이 많은 연구 그룹들에 의해서 이루어지고 있다. 미세구동소자에 응용을 하기 위해 개발되어지고 있는 여러 가지 소재들 중 $\ulcorner$형상기억합금 $\lrcorner$은 기존의 바이메탈이나 피에조 소자에 비하여 작동거리가 우수하기 때문에 그 가능성을 인정받고 있지만, 벌크재료는 느린 냉각속도 때문에 반응속도가 느린 단점이 있기 때문에 박막화 할 필요성이 있다. 이러한 이유로 여러 그룹들에 의해 형상기억합금의 박막화가 시도되고 있으나, 조성에 의해 특성의 변화가 심한 형상기억합금의 정밀한 조성제어가 힘들다고 알려져 있다. 몇몇 연구 그룹에서 RF magnetron sputtering법을 이용하여 Ti-Ni합금 박막을 성공적으로 제조하였다는 보고가 있지만, 타겟 조성 및 형태 등의 정밀한 제어가 필요하므로 3원 합금 박막 등을 제조할 경우에는 또 다시 타겟의 조건을 정밀하게 제어해야 할 필요성이 있다. 따라서 본 연구에서는 산화물 박막등의 제조에 있어서 타겟 조성과 제조된 박막 조성이 잘 일치하여 조성제어가 쉽게 이루어진다고 알려져 있는 PLD법을 도입하여 형상기억합금 박막제조에 적용가능한지를 검토하는 것을 목적으로 하였다.

• Proceedings of the KIEE Conference
• /
• 2008.10b
• /
• pp.407-408
• /
• 2008

한의학 관점의 진맥위치는 요골동맥상의 촌/관/척 세부위로 나누어진다. 거의 말초에 해당하는 근접한 부위를 세 부분으로 나누어 진맥하여 병을 진단하는데 촌/관/척 위치에 대한 해부학적 혈류역학적 근거는 부족한 상황이다. 본 논문에서는 초음파(VOLUSION730 PRO, GE Medical 미국)를 이용하여 맥진 위치의 혈관굵기, 혈관깊이 그리고 혈류 속도를 측정하고 분석해 봄으로써 맥진 위치의 구조석 차이를 이해해 보고자 한다. 또한 Body Mass Index(BMI)에 따라 혈관의 특성이 달라지는지 파악하고 한의맥진과의 상관관계를 분석해 보았다. 심혈관 질환이 없는 남자 피험자를 각각 BMI 정상인 그룹, 저체중 그룹, 과체중 그룹으로 나누어 5명씩 측정하였다. 좌, 우 손목의 맥진위치(촌, 곽, 척)에서 혈관깊이, 혈관굵기, 혈류속도를 측정하였으며 맥진기(3-D Mac, 대요메디, 한국)를 이용하여 맥파를 측정하였다. 그 결과, 비만도에 따라 혈관의 특징이 다르게 나타남을 알 수 있었으며 한의 맥의 종류 중 부맥과 치맥에 특징이 비만도와 관련 있음을 알 수 있었나 이는 피험자의 혈관 특성과 BMI 정보가 진단에 중요한 지표이며 자동 맥진 알고리즘 개발 시 반드시 고려해야 하는 사항임을 알 수 있다.

• Journal of the Institute of Electronics Engineers of Korea SD
• /
• v.45 no.1
• /
• pp.37-42
• /
• 2008

In this paper, we propose a partial product addition method using variable groups in the design of operators such as multipliers and digital filters. By this method, full adders can be replaced with simple logic circuits. To show the efficiency of the proposed method, we applied the method to the design of squarers and precomputer blocks of FIR filters. In case of 7 bit and 8 bit squarers, it is shown that by the proposed method, area, power and delay time can be reduced up to {22.1%, 20.1%, 14%} and {24.7%, 24.4%, 6.7%}, respectively, compared with the conventional method. The proposed FIR precomputer circuit leads to up to {63.6%, 34.4%, 9.8%} reduction in area, power consumption and propagation delay compared with previous method.

• Journal of KIISE:Computer Systems and Theory
• /
• v.31 no.11
• /
• pp.617-625
• /
• 2004

We propose an efficient stream authentication scheme that is an improvement of PCC scheme by using information dispersal algorithm. The drawback of PCC scheme is that received packets for each group are verifiable only if the signature packet of the group is successfully received. The proposed scheme processes the signature packet by introducing some amount of redundancy and splitting the result into pieces, which are then transmitted. The receiver is able to reconstruct the signature packet if the number of the received pieces is larger than the threshold. It is shown that under the same communication overhead verification probability of the proposed scheme is higher than that of SAIDA. Moreover, its computational cost is lower than that of SAIDA.

• Journal of the Korea Convergence Society
• /
• v.7 no.1
• /
• pp.49-55
• /
• 2016

In a delegate authentication, a user can lend his/her own authentication data to the third parties to let them be authenticated instead of himself/herself. The user authentication schemes based on the memory of unique data such as password, are vulnerable to this type of attack. Biometric authentication could minimize the risk of delegate authentication since it uses the biometric data unique by each person. Group authentication scheme is used to prove that each group member belongs to the corresponding group. For applications such as an electronic voting or a mobile meeting where the number of group members is changing dynamically, a new group authentication method is needed to reflect the status of group in real time. In this paper, we propose biometric authentication based dynamic group signature scheme. The proposed scheme is composed of biometric key generation, group public key creation, group signature generation, group signature verification and member update protocols. The proposed member update protocol is secure against colluding attacks of existing members and could reflect group status in real time.

• The Korean Journal of Applied Statistics
• /
• v.18 no.1
• /
• pp.1-13
• /
• 2005

Latent Class model has been considered recently by many researchers and practitioners as a tool for identifying heterogeneous segments or groups in a population, and grouping objects into the segments. In this paper we consider data on prostate cancer patients from Korean National Cancer Institute and propose a method for grouping prostate cancer patients by using latent class Poisson model. A Bayesian approach equipped with a Markov chain Monte Carlo method is used to overcome the limit of classical likelihood approaches. Advantages of the proposed Bayesian method are easy estimation of parameters with their standard errors, segmentation of objects into groups, and provision of uncertainty measures for the segmentation. In addition, we provide a method to determine an appropriate number of segments for the given data so that the method automatically chooses the number of segments and partitions objects into heterogeneous segments.

• Journal of the Korea Society of Computer and Information
• /
• v.6 no.1
• /
• pp.103-112
• /
• 2001

As electronic environment is changed owing to the developments of computers and telecommunication technique, the meaning of working process is changed because individual working process is shifted to overall working process of each groups while main frame is transferred to server environments. By using groupware, productivity of office work's is increased not only quality matter but also quantity matter and rapid and various services are provided. In order to realize united office automation, when educational programs are assembled at office automation related departments in junior colleges, it will help to stress importance of groupware.

• Convergence Security Journal
• /
• v.16 no.7
• /
• pp.121-127
• /
• 2016

Recently, the popularity of smart devices such as Wi-Fi and LTE has increased the use ratio of wireless dramatically. On the other hand, the use ratio of wired internet is decreasing. The IoT(Internet of Things) is not only for people but also for communication between people and things, and communication between things and things by connecting to a wireless without choosing a place. Along with the rapid spread of the IoT there is a growing concern about the threat of IoT security. In this paper, the proposed scheme is a efficiency group key agreement in IoT environment that guarantees secure communication among light-weight devices. The proposed scheme securely be able to communication with the group devices who share a group key, generated by own secret value and the public value. Such property is suitable to the environment which are required a local area and a group.