실내 무선 채널 환경에서 무선 LAN용 OFDM 시스템의 성능 분석

최연주,김항래,김남,고영훈,안재형,Choi, Yeoun-Joo,Kim, Hang-Rae,Kim, Nam,Ko, Young-Hoon,Ahn, Jae-Hyeong 한국전자파학회 2001 한국전자파학회논문지 Vol.12 No.2

본 논문에서는 IEEE 802.11a 무선 LAN에 적합한 OFDM 시스템에 비터비 복호를 사용하는 길쌈 부호와 단일 탭의 LMS 등화기를 적용하여 실내 무선 채널 환경에서 시스템 성능을 시뮬레이션을 통해 분석한다. 실내 무선 채널은 라이시안 페이딩 모델링하고, 부채널변조 방식으로는 QPSK와 16QAM을 사용한다. 직접 파 대 간섭파 전력비 K=5 dB 인 라이시안 페이딩 채널에서 길쌈 부호 및 비터비 복호를 사용하는 경우, 경판정에서 QPSK는 8.6 dB, 16QAM 은 19.2dB, 연판정에서 QPSK는 5.3dB, 16QPSK는 5.3dB, 16QAM은 9.8dB에서 $10^{-4}$의 BER을 만족하였다. 또한 16QAM/OEFM 방식에 단일 탭의 LMS 등화기를 사용하면 길쌈 부호만을 사용한 경우보다 경판정 비터비 복호의 경우 8.6dB,연판정의 경우에는 2dB의 성능이 향상됨을 알 수 있었다. In this paper, the system performance with the convolution code using a Viterbi decoding and the one tap LMS equalizer applied to the OFDM system, which is suitable for IEEE 802.1la wireless LAN in indoor wireless channel, is analyzed through computer simulation. Indoor wireless channel is modeled as Rician fading channel, and QPSK and 16QAM scheme are used for subchannel modulation. In Rician fading channel with the power ratio of the direct path signal to the scattered signals, K=5 dB, BER of $10^{-4}$ is satisfied if the SNRs of the QPSK/OFDM and the 16QAM/OFDM are 8.6 dB and 19.2 dB in hard decision and 5.3 dB and 9.8 dB in soft decision, respectively. Compared with convolution code scheme, it is observed that 16QAM/OFDM system with the one tap LMS equalizer has the performance improvement of 8.6 dB and 2 dB in hard decision and soft decision, respectively.

Far Ultraviolet Observations of the Spica Nebula and the Interaction Zone

최연주,박재우,민경욱,선광일,조영수,Choi, Yeon-Ju,Park, Jae-Woo,Lim, Tae-Ho,Min, Kyoung-Wook,Seon, Kwang-Il,Jo, Young-Soo 한국천문학회 2012 天文學會報 Vol.37 No.2

We report the results of our analysis of far ultraviolet (FUV) observations made for the broad region around the ${\alpha}$ Vir (Spica) including the interaction zone of the Loop I and the Local Bubble. We employed the datasets of the GALEX and the FIMS, which made observations at similar FUV wavelengths. First, we noted that the GALEX image was enhanced in the southern region where the interaction zone exists. We attribute this enhanced FUV emission to dust scattering of the stellar photons, mostly from the background field stars with small contributions from the central star Spica. While the region is optically thin in general, the FUV intensity did not correlate well with the dust extinction level, indicating that the local radiation field has significant fluctuations. On the other hand, the GALEX FUV intensity well with the $H{\alpha}$ intensity as well as the dust extinction level in the northern part. In fact, the neutral hydrogen column density correlated very well with the dust extinction level throughout the whole region in consideration. The relationship between the neutral hydrogen column density and the color excess was estimated to be ${\sim}7{\times}10^{21}atoms\;cm^{-2}$, which is a little higher than the previous observations made for a diffuse interstellar medium. The spectral analyses of the FIMS observations showed the enhanced C IV emission throughout the whole region, indicating that the C IV emission arises by the interaction of the hot gases with the shell boundaries. A simple model showed that a large portion of the C IV emission comes from the Loop I side of the interaction zone, compared to the Local Bubble side. The FIMS spectrum also showed indications of the molecular hydrogen fluorescence lines for the interaction zone.

재활용 폴리에스터 칩의 물성 향상 연구

최연주,이중규,김성훈,임기섭,이주형,이준희,Choi, Yeon-Joo,Lee, Jung-Gyu,Kim, Seong-Hun,Lim, Ki-Sub,Lee, Joo-Hyung,Lee, Jun-Hee 한국섬유공학회 2011 한국섬유공학회지 Vol.48 No.2

To improve the physical properties of recycled polyester chips, virgin PET chips were compounded with the ratio of 20 wt%, 40 wt%, and 70 wt%. Recycled PET chips blended with virgin PET chips exhibited decreased molecular weights and intrinsic viscosities compared with 100% recycled PET chips and virgin PET chips, and this was caused by thermal and hydrolytic decomposition. End-group contents and MFI both increased in the blended PET chips. As the virgin PET chip contents increased in the recycled PET chips, the melting temperature tended to increase. Recycled PET chips exhibited a higher crystallization temperature compared with virgin PET chips. Morphologies of recycled PET films were analyzed by scanning electron microscopy (SEM). Yellowing of recycled PET chips resulted from intramolecular cross-linking and oxidation reactions. As virgin PET chips were compounded with recycled PET chips, yellowing was reduced. The ash contents were increased in the recycled PET chips which were blended with virgin PET chips. As recycled PET chip contents were similar to those of virgin PET chips, the ash contents were the highest in the experimental materials.

눈꺼풀에 발생한 림프종모양 구진증 1예

최연주,진현철,김남주,정호경,곽상인.Youn Joo Choi. MD. Hyun Chul Jin. MD. Nam Ju Kim. MD. Ho Kyung Choung. MD.Sang In Khwarg. MD. 대한안과학회 2013 대한안과학회지 Vol.54 No.4

Purpose: Lymphomatoid papulosis (LyP) is one of the primary cutaneous CD30-positive lymphoproliferative disorders. LyP of the eyelid has rarely been reported. Herein, a case of typical LyP of the medial canthal area is reported. In addition, a literature review was performed. Case summary: A 40-year-old female presented with a skin mass in the medial canthal area of the left eye that developed 2 months earlier. Initially, a focal skin lesion developed, and even with conservative treatment at a local clinic, progressed to a mass lesion having a central ulceration and adjacent edema. After 6 weeks, the adjacent edema had gradually decreased. On ophthalmic examination, the left medial canthal lesion was a 6 x 6 mm sized elevated mass with a central crater covered by crust. The clinical impression was keratoacanthoma. The lesion was widely excised and reconstructed by a full-thickness skin graft after an incisional biopsy. Histopathologic findings showed dermal infiltration of various inflammatory cells with atypical lymphocytes showing positivity to the CD30 antigen, and LyP was diagnosed. Systemic evaluation showed no evidence of systemic lymphoma and the patient has remained free of recurrence or systemic disease after a 1-year follow-up.

백내장수술 중 낙하된 유리체내 수정체로 의뢰된 잔류수정체 제거술의 결과

최연주,최경식,이성진,이미리,Youn Joo Choi,MD,Kyung Seek Choi,MD,PhD,Sung Jin Lee,MD,PhD,Mi Ri Rhee,MD 대한안과학회 2012 대한안과학회지 Vol.53 No.1

Purpose: To assess the clinical features and outcomes of patients referred for management of dropped lens fragments during cataract surgery. Methods: The medical records of 22 eyes from 22 patients who were referred to our hospital to undergo pars plana vitrectomy (PPV) for management of dropped lens fragments after phacoemulsification surgery at private clinics were reviewed. Data including patient demographics, preoperative and postoperative visual acuity, factors associated with dropped lens fragment, and postoperative complications were recorded. The factors were compared between 2 patient groups: postoperative Snellen acuity of 0.5 or better and acuity less than 0.5. The statistical significances of differences in factors between the 2 groups were calculated. Results: The mean interval between cataract surgery and PPV was 2.6 ± 3.7 days. At the final examination, the mean postoperative acuity was 0.57 ± 0.20, and 16 eyes (72.7%) had a visual outcome of 0.5 or better. After excluding 7 eyes with other pre-existing ocular co-morbidities, 14 eyes (93.0%) achieved a final visual acuity of 0.5 or better. Multivariate analysis showed that the predictor for visual outcomes of 0.5 or better was absence of preoperative eye disease (p = 0.007). Complications after PPV included 2 (9.0%) cases of cystoid macular edema and 1 (4.5%) case of retinal detachment. Conclusions: Prompt referral and surgical management within 1 week for dropped lens fragments during cataract surgery may achieve a better visual outcome in cases with no pre-existing eye disease. J Korean Ophthalmol Soc 2012;53(1):68-75

전층각막이식 봉합사 제거 후 외상에 의해 발생한 지연성 축출성 맥락막상강출혈 1예

최연주,정문선,Youn Joo Choi,Moon Sun Jung 대한안과학회 2011 대한안과학회지 Vol.52 No.3

Purpose: To report a case of delayed-onset expulsive suprachoroidal hemorrhage due to trauma after removal of a penetrating keratoplasty suture. Case summary: A 66-year-old man had penetrating keratoplasty for bullous keratopathy performed in his left eye. After 1 year, the continuous suture was removed for adjustment of astigmatism. Four days after removal of the suture, the patient struck his left eye with the back of his hand, although at the time of injury he had no specific symptoms. Two days later, the patient noticed abrupt pain, decreased visual acuity, and massive hemorrhage in his left eye. Examination revealed an inferior wound dehiscence of approximately 8 clock hours (2 thru 10 o’clock) with prolapsed intraocular contents such as the uvea and retina. The patient underwent cornea graft resuturing with resection of ocular contents, which could not be repositioned. Although bleeding was controlled after the operation, vision was lost in his left eye. After two months, according to decrement of intraocular hematoma, the patient had a phthisis bulbi with low intraocular pressure in his left eye. Conclusions: Persistent low intraocular pressure due to wound leakage through the graft-host junction likely resulted in delayed onset of expulsive suprachoroidal hemorrhage. The risk of traumatic corneal graft rupture after penetrating keratoplasty is significant and is associated with a poor visual outcome and eyeball viability. Therefore, patients should be cautioned. In addition, the importance of eye examination after trauma should be emphasized. J Korean Ophthalmol Soc 2011;52(3):359-363

리싸이클 폴리에스터 니트 소재의 물리적 성질 및 태 평가

최연주,김성훈,임기섭,Choi, Yeon-Joo,Kim, Seong-Hun,Lim, Ki-Sub 한국섬유공학회 2012 한국섬유공학회지 Vol.49 No.2

With regards to environmental conservation, it is necessary to promote an eco-friendly industry and to recycle wastes. In this study, the physical properties and hand values of material recycled PET knit fabrics prepared with various recycled PET yarns were investigated. Bursting strengths of 3 recycled PET knit fabrics were higher than that of regular PET knit fabric. 3 Recycled PET knit fabrics were more flexible than those of the regular PET knit fabric. Lightness of regular PET knit fabric was the highest among the 5 samples. Fabric knitted with recycled non-circular PET yarns had a more yellowish tinge. Mechanical properties were measured using the KES-FB system. Bending properties, shear properties, weight, and thickness were increased in recycled PET knit fabrics. The compressional linearity and energy of 3 recycled PET knit fabrics increased. However, their compressional resilience was reduced. In addition, coefficients of friction were similar. Regular PET knit fabric demonstrated a smooth appearance. Numeri was the highest in the hand values.

『남양선생시집』 간행과 『고려대장경』 조성사업

최연주 ( Choi Yeon-joo ),전진이 ( Jun Jin-yi ),한홍익 ( Han Hong-ik ) 한국밀교학회 2022 불교학밀교학연구 Vol.1 No.-

『남양선생시집』은 고려 무인집권기에 문신관료였던 백분화의 시집이다. 그는 스스로 參禪居士라 할 정도로 禪法을 좋아하였다. 이 시집은 백분화의 장남인 희심이 간행을 주도하였다. 승려이자 문인이었던 희심은 부친이 생전에 남긴 시 2백여 首를 수습해 上下卷으로 편찬하고, 제목과 서문을 이규보 아들인 이함에게 의뢰하였다. 백분화는 이규보보다 나이가 10살 적었지만 일찍 出仕하였다. 최씨정권과 밀착되었던 백분화는 이규보의 출사를 위해 다방면으로 도움을 주었을 것이다. 이는 두 사람이 주고 받은 詩와 이규보가 지은 백분화의 묘지명을 통해 충분히 짐작할 수 있다. 이러한 두 사람의 관계는 아들인 희심과 이함에게 자연스럽게 이어져 시집의 제목과 서문 작성 배경이 되었을 것이다. 『남양선생시집』은 『고려대장경』 조성사업이 마무리된 직후인 고종 36년(1249)에 간행되었다. 시집에서 惠堅과 孝眞이라는 각수가 조사되었는데, 이들은 『고려대장경』 판각에 참여한 각수이다. 시집 간행이 『고려대장경』 판각과 밀접하게 연관되어 있음을 보여준다. 『남양선생시집』 간행 과정을 검토해 보면 이규보의 『동국이상국집』 간행과 유사한 점이 많다. 그렇다면 『고려대장경』 조성사업의 체계를 활용하여 분사대장도감(이하 분사도감으로 약칭함)에서 『남양선생시집』을 간행하였을 개연성이 매우 높다. 『Namyang Seonsaeng Sijib』(『南陽先生詩集』) is a collection of Beak Bunhwa(白賁華) in a period of the Choi military regime. He had continuously interchanged with the Buddhist community including reputed monks. 『Namyang Seonsaeng Sijib』 was published by monk Huisim(希諗), the eldest son of Beak Bunhwa. Twenty-five years after the death of his father, Huisim had collected scattered poems and compiled them into two volumes. Yi Ham(李涵), the son of Yi Gyubo(李奎報), wrote the preface of it. Likewise, Yi Gyubo wrote the epitaph of Beak Bunhwa. Beak Bunhwa and Yi Gyubo were deeply involved in politics and literature. To sum up this causality, these two families had a quite friendly relationship. Meanwhile, 『Namyang Seonsaeng Sijib』 was released immediately after the engraving of 『Tripitaka Koreana』. Hyegyeon(惠堅) and Hyojin(孝眞), engravers who participated in the engraving 『Tripitaka Koreana』, undertook repeatedly the editing of 『Namyang Seonsaeng Sijib』. It shows that publication of 『Namyang Seonsaeng Sijib』 and engraving of 『Tripitaka Koreana』 are closely linked. Beak Bunhwa and Yi Gyubo are politicians who cooperated with the Choi military regime. As 『Donggukyisanggukjip』(『東國李相國集』), the collection of Yi Gyubo, was produced in Bunsadogam(分司都監) with the support of King Gojong and the Choi military regime, it is highly likely that 『Namyang Seonsaeng Sijib』 was produced in the same time.

논문 : 『고려대장경』 각성인의 참여형태와 조성공간 : Peoples and the Places

최연주 한국중세사학회 2004 한국중세사연구 Vol.0 No.16

This paper is a study on the participation method of Kakseongins(刻成人) and the engraving location of Goryeodaejangkyeong(高麗大藏經). The compared and classified the participation method of Kakseongins in Goryeodaejangkyeong work. And the investigated how each pictorial book was made and how they managed the process. The participation method of Kakseongins can be divided into two types. The first type is engraving on wood of one whole volume by only one Kakseongin. The second type is making one volume by more than two Kakseongins. The synergic work of more than two Kakseongins was done in accordance with unit one volume. The synergic participation method was very popular after the 30th year of Kojong(高宗) when Bunsadogampan(分司都監板) began to be produced. At the beginning of engraving, both of the two types went side by side. But after the 30th year of Kojong, the first type decreased and the second type increased. It was changed but to a synergic involvement method of a plate of the sutras center after the Bunsadogampan was produced. So that the sutra of the engraved since an ancient the 30th year of Kojong was the newcomer than former time and had consequently plenty Kakseongin. This is understood an awakening business organization of the Daejangdogam(大藏都監) and Bunsadogam(經板) structure setup as the result to be reflected. The wood engraving location or furtherance location of the Kyeomgpan(分司都監) which is the empty room is not a specific area. We are namely the government office empty room and employee existing location which is established anew. We were made up his task at same time and made finally in the Daejangdogam or Bunsadogam. An each pictorial book had particular operation system. One Kakseongin worked in both Daejangdogam and Iunsadogam in the same year, and it reflects that the two organizations had does cooperation system. The Goryeodaejangkyeong was consist of Daejangdogam-the central organization, and ßunsadogam-nation-wide organization system, and wood engraving location-the sub-structure under each Dogam(都監) organization system. The wood engraving location seems to have contained the maintained before national wood engraving location, temples and new built wood engraving location. The furtherance location of pictorial an each book under influence of constructed therefore strict cooperation system.

『고려국신조대장교정별록(高麗國新雕大藏校正別錄)』의 교감(校勘) 유형과 성격

최연주 ( Choi Yeon-joo ) 東亞大學校附設 石堂傳統文化硏究院 2017 石堂論叢 Vol.0 No.68

본고는 江華京板 『高麗大藏經』(이하 『고려대장경』으로 약칭) 彫成 중 수기대사 등이 교감한 경전에 대한 논의를 정리한 『高麗國新雕大藏校正別錄』(이하 『교정별록』으로 약칭)에 대해 교감 유형과 경전의 교감 방식에 두 가지 측면에서 논의하였다. 첫째, 기존 연구 성과를 통해 『교정별록』이 최고 교감본으로서 위상과 그 가치를 검토하였다. 또 조성 추이와 교감 과정 및 그 유형에 대해 살펴보았다. 『교정별록』은 『개원석교록』을 중심으로 교감 대상 경전을 채택하고, 교감 방식에 있어서 당시 동아시아에 산재한 다양한 경전과 목록집을 내용과 對校本別로 구분해 교감하였다. 대장도감에서 기존의 권내교감기를 다시 정리하여 편찬하였다. 한편 권내교감기와 『교정별록』 내용에 대해 상호 대조는 물론 한국중세사, 불교학, 서지학 등 학제간 연구가 필요하다. 둘째, 『교정별록』에 수록된 경전의 著·譯者, 조성 년도와 도감 등을 현황과 주요 내용을 살펴보면서, 校勘 및 對校에 대해 검토하였다. 특히 권4의 『最勝燈王如來經』과 권27의 『金七十論』에 대한 교감 내용을 주목하였다. 교감 과정에서 『최승등왕여래경』이 단본에서 발견되어 추가된 것이다. 對校를 통해 송본에 『최승등왕여래경』이 없음을 확인하고 『고려대장경』에 편입시켰다. 이를 구분하기 위해 권수제 및 권미제의 經名 다음에 `丹本`, 函次에 이어 細字로 `丹`이라고 표기해 추후 잘못된 교감이라면 바로 잡을 수 있도록 하였다. 『금칠십론』은 국본·송본·단본의 교감을 통해 문장의 오류 및 착란을 바로 잡은 것이 아니다. 『개원석교록』과 『長房內典』 등 목록의 비교 검토를 통해 불교의 정통 경전이 아니라는 점을 적시해 두었다. 『금칠십론』이 비록 外道의 경전이지만, 후대를 위해 『고려대장경』에 편입시켰다. 수기대사를 비롯한 교감자들은 嚴正하게 교감을 진행하였다. 교감 과정에서 특정 국가의 체제나 목록에만 의거하지 않고, 각 本을 對校한 후 『고려대장경』에 편입시켰다. 그 편제가 정형화된 것이 아니라 상황에 따라 탄력적이고 융통성 있게 운영되었음은 『最勝燈王如來經』과 『金七十論』을 통해 이해할 수 있다. 교감자들이 동아시아에 산재한 대장경에 대한 관심과 공부를 꾸준히 해 왔음을 알 수 있다. This study had been discussed with two ways about `Koryokukshinjodaechangkyochongbyollock`. By collecting existing research, `Koryokukshinjodaechangkyochongbyollock` is recognized the top of a revised scriptures. Various perception and method will build the foundation which strengthen understanding of `Koryokukshinjodaechangkyochongbyollock`. However, following of the research, irrational case of research must be complemented. And comparison of the revised scriptures between `Koryokukshinjodaechangkyochongbyollock` and Tripitaka Koreana is necessary for study. Also, joint research with Historiography, Buddhology and bibliography must go ahead to encourage study of `Koryokukshinjodaechangkyochongbyollock`. This is a part of author and translator who had included in scriptures `Koryokukshinjodaechangkyochongbyollock` as well as Dogam(都監) and period when it carved. The revised scriptures of `Koryokukshinjodaechangkyochongbyollock` was not processed for the whole of scriptures but for scriptures which is brought up problem. It is supposed to made by using Tripitaka Koreana`s list in the process of comparison with some scriptures. Revising of `Koryokukshinjodaechangkyochongbyollock` is mutually associated with its carving, so it efficiently went along with Daejangdogam(大 藏都監). `Agrapradipadharanividyaraja(最勝燈王如來經)` and `Suvarnasaptati (金七十論)` -Scriptures which is the revising object in `Koryokukshinjodaechangkyochongbyollock`- is out of the ordinary. `Agrapradipadharanividyaraja` was later than another revised scriptures and `Suvarnasaptati` was confirmed not Buddhism scriptures. `Agrapradipadharanividyaraja` was nonexistent in Song dynasty`s Tripitaka, however it was discovered in Liao Dynasty`s Tripitaka when Tripitaka Koreana was carved and added to Tripitaka Koreana. Tripita Koreana and part which added to `Koryokukshinjodaechangkyochongbyollock` respectively were same edition. But `Agrapradipadharanividyaraja` of the Tripitaka Koreana was carved in King Gojong 33 year, but `Agrapradipadharanividyaraja` of the `Koryokukshinjodaechangkyochongbyollock` was carved in King Gojong 34 year and different technicians conducted. In other words, it was added to Tripitaka Koreana additionally. To separate this, it was designed to if something had wrong letters, it could be marked `DanBon(丹本)` behind the first section and last section in the scripture`s name and small letter `丹(Dan)` behind Ham(函) to be revised. `Suvarnasaptati` was not authentical Buddhism scriptures by comparison of the East Asia (Song, Goryeo, Liao Dynasty)`s Tripitaka. But it was added to Tripitaka Koreana. We can presume Reviser like monk Sugi(守其) had conducted the revising prudently. Finally, Reviser of Tripitaka Koreana had a continuous interest to Tripitaka where located in East Asia and studied. They compared with various type of Tripitaka and added as well Certain nation`s system and list in the revising to Tripitaka Koreana. So this organization was not behind the times and not standardized but it showed operation with mutual and flexible process situationally.