Reduced RBF Centers Based Multiuser Detection in DS-CDMA System

이정식,화재정,박지연,Lee, Jung-Sik,Hwang, Jae-Jeong,Park, Chi-Yeon The Korea Institute of Information and Commucation 2006 韓國通信學會論文誌 Vol.31 No.11C

The major goal of this paper is to develop a practically implemental radial basis function (RBF) neural network based multi-user detector (MUD) for direct sequence (DS)-CDMA system. This work is expected to provide an efficient solution for RBF based MUD by quickly setting up the proper number of RBF centers and their locations required in training. The basic idea in this research is to estimate all the possible RBF centers by using supervised ${\kappa-means$ clustering technique, and select the only centers which locate near seemingly decision boundary between centers, and reduce further by grouping the some of centers adjacent each other. Therefore, it reduces the computational burden for finding the proper number of RBF centers and their locations in the existing RBF based MUD, and ultimately, make its implementation practical.

올바른 교육풍토가 아쉽다

이정식,Lee, Jeong-Sik 한국건강관리협회 1990 건강소식 Vol.14 No.10

대도시의 위락공간 배치에 관한 연구

이정식,Lee, Jeong-Sik 대한건축사협회 1972 建築士 Vol.1972 No.3

국토정책의 싱크탱크 "국토연구원"

이정식,Lee, Jeong-Sik 한국대학교육협의회 2002 大學敎育 Vol.116 No.-

농어 (Lateolabrax japonicus) 피부계 지지세포와 선세포의 미세구조

이정식,김재원,Lee, Jung-Sick,Kim, Jae-Won 한국현미경학회 1999 Applied microscopy Vol.29 No.4

농어의 피부는 크게 상피층과 진피층으로 구분된다. 상피층은 지지세포와 단세포선들로 구성된다. 지지세포는 표면세포, 중간세포 및 기저세포로 구분된다. 선세포는 점액분비세포와 곤봉상세포로 구분되는데, 이들의 분포밀도는 곤봉상세포가 더 높다. 표면세포는 편평형 또는 입방형이며 세포질에는 조면소포체가 잘 발달되어 있으며, microridge가 뚜렷하다. 표면세포들은 membrane interdigitation구조와 부착반에 의해서 다른 세포들과 연결되어 있다. 중간세포는 난형이며, 전자밀도는 다른 지지세포 보다 높다. 기저세포는 입방형이며, 세포소기관의 가운데 미토콘드리아의 발달이 현저하며, membrane interdigitation 구조들이 발달되어 있다. 점액분비세포는 막으로 싸인 다수의 분비과립들을 함유한다. 곤봉상세포의 세포질은 수질부와 피질부로 구분되는데, 수질부에서는 핵, 세포소기관, 중심공포가 관찰되며, 피질부에서는 발달된 장미세섬유들이 관찰된다. 곤봉상세포들은 잘 발달된 membrane interdigitation구조와 부착반에 의해서 다른 세포들과 연계되어 있다. The present investigation is designed to provide basic information on fine structure of the skin of the sea bass, Lateolabrax japonicks in relation to study of epidermal change with environmental and physiological change. The skin of the sea bass is divided into the epidermal layer and dermal layer. Epidermal layer consists of supporting cells and unicellular glands. The supporting cells were classified into the superficial cell, intermediated cell and basal cell. Gland cells were classified into the mucous secretory cell and club cell which is more frequently observed. Superficial cell of epidermal layer is squamous or cuboidal and contains well-developed rough endoplasmic reticulum and the surface is covered with numerous microridges. Superficial cells are connected to another cell with membrane interdigitations and desmosomes. Intermediated cell is ovoid and the electron density is higher than the other supporting cells. Basal cell is cuboidal and has a well-developed mitochondria and membrane interdigitation. The mucous secretory cell has a numerous membrane bounded secretory granules. The cytoplasm of club cell is divided into cortex and medullar. The medullar cytoplasm has a nucleus, intracellular organelles and central vacuole, and the cortical cytoplasm has a well-developed tonofilament. Club cells are connected to another cell with well -developed membrane interdigitations and desmosomes.

대하(Penaeus chinensis) 아가미의 형태 및 미세구조

이정식,강주찬,정선영,Lee, Jung-Sick,Kang, Ju-Chan,Jeong, Seon-Young 한국현미경학회 2000 Applied microscopy Vol.30 No.3

대하 아가미의 형태와 미세구조를 광학현미경과 전자현미경으로 조사하였다. 대하는 수지형 아가미를 가진 다. 아가미는 출새관과 입새관을 구분하는 세로 격벽을 가진다. 각각의 새판은 전자밀도가 다른 다층구조의 큐터클로 싸여 있다. 새판 기저세포들은 편평형이며, 전자밀도가 높은 세포질을 가진다. 상피세포층은 단층으로 큰 핵을 가진 편평상피로 구성된다. 새판의 기둥구조는 세로방향의 미세소관들과 측면 membrane interdigitation을 가진다. AB-PAS음성 분비세포들은 다세포선의 형태이다. 활성화된 선에서 각 세포의 경계부는 뚜렷하지 않으며, 세포질에는 활면소포체, 미토콘드리아, 전자밀도가 낮으며 막을 가진 분비소포들과 granular rosettes를 가진다. 비 활성화된 선에서는 세포 경계가 뚜렷하며, 세포질에서는 전자밀도가 높은 다수의 작은 과립들이 산재한다. 그리고 alcian blue에 양성인 단세포 분비세포들은 세포질에 발달된 다수의 골지체와 조면소포체들을 함유한다. The gill morphology and ultrastructure of the fleshy shrimp, Penaeus chinensis were investigated by light and electron microscopy. Fleshy shrimp has dendrobranchiate gills. Gill has a longitudinal septum dividing them into afferent and efferent channel. Each gill lamella is covered by multi-layered thin cuticle of different electron density. The lamella basal cell is squamous and contains cytoplasm of electron dense. Simple epithelial layer consists of squamous epithelium contained large nucleus. The lamella pillar structures are characterized by the axial microtubules and lateral membrane interdigitations Secretory cells of AB-PAS negative are multicellular gland. In active gland each cell boundary is not apparent and the cytoplasm contains smooth endoplasmic reticula, mitochondria, membrane-bounded secretory vesicles of low electron density and granular resettes. In inactive gland each cell boundary is apparent and the cytoplasm is occupied with numerous small granules of electron dense. The well-developed rough endoplasmic reticula and Golgi apparatus are observed in the unicellular gland of alcian blue positive.

통계적 방법에 의한 지점강우의 권역화 연구

이정식,신창동,김영욱,Lee,Jung-Sik,Shin,Chang-Dong,Kim,Young-Wook 한국방재학회 2007 한국방재학회 학술발표대회논문집 Vol.2007 No.1

The objective of this study is to analyze the regionalization of point rainfall by statistical methods for regional frequency analysis of the rainfall. The rainfall data used in this study are annual maximum rainfall at 57 stations during the period of more than 30 years for 12 durations(10min, 1, 2, 3, 4, 5, 6, 8, 10, 12, 18, 24hr) in Korea. The Mann-Whitney U test, Kruskal-Wallis one-way analysis of variance of nonparametric test the principal component and the cluster analysis have been performed to analyze the regionalization of rainfall. The results of this study are as follows; (1) The region which hydrological homogeneous is accepted does not exist for whole duration in Korea. (2) The result of nonpametric test shows that hydrological homogeneous regions of point rainfall are divided by 5 regions. (3) In case of cluster analysis hydrological homogeneous regions of point rainfall are divided by 6 regions and 4 other areas.

투명표본(透明標本)에 의(依)한 하악견치(下顎犬齒)의 근관형태(根管形態)에 관(關)한 연구(硏究)

이정식,Lee, Chung-Sik 대한치과보존학회 1978 Restorative Dentistry & Endodontics Vol.4 No.1

Fifty two mandibular permanent canines were chosen to study the anatomy of the root canal. The experimental teeth were injected with China ink, decalcified, cleared and observed to investigate the number of root canals, frequency and location of lateral canals, the location of apical foramens, the frequency of apical deltas, and the curvature of root canals. The results were as follows: 1) all of the experimental teeth demonstrated single canal. 2) of the 52 canals, 9.6% of the canals were found to have lateral canals and the locations of the lateral canals were in the apical third of the roots 3) Thirty three apical foramens were located laterally on the root apices and nineteen foramens were located on the centers of the root apices. 4) 37 canals showed straight curvature, 12 canals distal curvature. 3 canals labial curvature.

기술력 배양과 합리적인 유통 구조의 구축을

이정식,Lee, Jeong-Sik 한국전자정보통신산업진흥회 1993 電子振興 Vol.13 No.12

투명표본(透明標本)에 의(依)한 상악제이구치(上顎第二臼齒)의 근관형태(根管形態)에 대(對)한 연구(硏究)

이정식,Lee, Jeong-Sik 대한치과보존학회 1980 Restorative Dentistry & Endodontics Vol.6 No.1

Fifty human maxillary second molars were injected with china ink, decalcified, cleared, and used in vitro study to determine the number of root canals, the frequency and location of lateral canals, canals per root, and frequency of apical deltas. The results were as follows. 1. The mesiobuccal root was found to contain a single primary canal in 62% of the teeth studied and two canals in 38% of the teeth studied. 2. In mesiobuccal roots with two canals, the seperated apical foramen appeared 24% of the specimens and the common apical foramen 14% of the specimens. 3. Of the 169 canals studied, 23.1% of the canals were found to contain lateral canals and these ramifications were mainly located in the apical third of the root.