변형된 방추형결막절제술 및 가쪽눈꺼풀판띠고정술에 의한 퇴행성 눈꺼풀겉말림의 교정

고상준,김상덕,Sang Jun Ko,Sang Duck Kim 대한안과학회 2012 대한안과학회지 Vol.53 No.2

Purpose: To evaluate the effects of the modified medial spindle and the lateral tarsal strip procedure in involutional ectropion patients. Methods: The lateral tarsal strip procedure with the modified medial spindle procedure that adjusts the size and the position of the spindle along the severity of lower eyelid eversion was performed on 17 eyes of 12 patients with involutional ectropion. The average follow-up period was 19.6 months. Results: All 12 patients were male, and the mean age was 65.4 years (range 54 to 78 years). There was no recurrence in any of the 17 eyelids. However, a mild lower lid retraction and a mild punctal eversion not requiring reoperation occurred in the follow-up period. Conclusions: The lateral tarsal strip procedure combined with the modified medial spindle appears to be effective in the surgical treatment of involutional ectropion. J Korean Ophthalmol Soc 2012;53(2):187-192

다중 사용자 OFDMA 시스템에서의 사용자간 전송효율 최적화를 위한 Aggressive Subchannel Allocation 알고리즘

고상준,허주,장경희,Ko Sang-Jun,Heo Joo,Chang Kyung-Hi 한국통신학회 2006 韓國通信學會論文誌 Vol.31 No.6A

본 논문에서는 OFDMA 시스템 하향 링크에서 섹터 Throughput을 향상시키기 위하여, 모든 사용자의 채널 상태를 고려하여 동적 채널 할당을 진행하는 ASA(Aggressive Subchannel Allocation) 알고리즘을 제안한다. 그리고 제안한 알고리즘을 섹터 별 Frequency Reuse Factor 가 1인 2-tier 환경 하에서 Round Robin, ACG(Amplitude Craving Greedy), RCG(Rate Craving Greedy) 그리고 GPF(General Proportional Fair) 알고리즘과 함께 모의실험을 통하여 각 알고리즘의 성능을 분석한다. 그 결과 본 논문에서 제안한 ASA 알고리즘이 Round Robin 보다는 58 %, ACG 보다는 190 %, RCG 보다는 130 % 그리고 GPF보다는 8.5 % 높은 Sector Throughput을 보인다. In this paper, we propose an ASA(Aggressive Subchannel Allocation) algorithm, which is an effective dynamic channel allocation algorithm considering all user's channel state to maximize downlink sector throughput in OFDMA system. We compare an ASA algorithm with Round Robin, ACG(Amplitude Craving Greedy), RCG(Rate Craving Greedy) and GPF(General Proportional Fair) in the 2-tier environment of FRF(Frequency Reuse Factor) 1 and then analyze the performance of each algorithms, through compute simulation. Simulation results show that the proposed ASA algorithm gets 58 %, 190 %, 130 % and 8.5 % better sector throughput compared with the Round Robin, ACG, RCG and GPF respectively.

802.16e OFDMA/TDD 셀룰러 시스템의 성능 최적화를 위한 부채널과 전송전력 결합 할당 알고리즘 Part I : 하향링크에서 공평성이 보장되는 수율 최대화 부채널 할당 알고리즘 및 잉여 전송전력의 효율적인 사용을 위한 전력할당 알고리즘

고상준,장경희,김재형,Ko, Sang-Jun,Chang, Kyung-Hi,Kim, Jae-Hyeong 한국통신학회 2007 韓國通信學會論文誌 Vol.32 No.3A

본 논문에서는 802.16e OFDMA/TDD 시스템의 하향링크에서 제안된 FASA (Fairness insured Aggressive Sub-channel Allocation) 알고리즘을 적용하여 사용자에게 적절한 부채널을 할당한 후, 제안된 Improved CHC 알고리즘을 통해 적절한 전송전력을 할당하는 결합할당 알고리즘을 제안한다. FASA 알고리즘은 선택된 사용자에게 최대의 채널 이득을 보장해줄 수 있는 복수개의 부채널이 존재할 경우, 그 중 주변 사용자들에게 가장 적은 채널이득을 보장해주는 부채널을 선택된 사용자에게 할당함으로써 시스템의 Throughput을 최대화 시키는 알고리즘이다. 또한 본 논문에서 제안된 Improved CHC 알고리즘은 사용자에게 할당되는 하향링크 전송 전력 중, 잉여전력을 수거하고 재할당함으로써 시스템의 전송전력할당의 효율성을 최대화 시키는 알고리즘이다. Improved CHC 알고리즘을 통해 추가적인 Throughput 및 공평성의 향상을 얻을 수 있다. This paper solves the problem of finding a suitable sub-channel and power joint allocation method for multiple users in 802.16e OFDMA/TDD cellular systems. The joint allocation is thatfirstly the sub-channel is allocated to the users and then suitable power is allocated. We propose a FASA (Fairness insured Aggressive Sub-channel Allocation) algorithm which is a dynamic channel allocation algorithm considering all users' channel state information conditionally to maximize fairness and throughput. The improved CHC algorithm, which is dynamic power allocation algorithm, is also proposed in this paper The Improved CHC algorithm collects the extra of the downlink transmit power and then re-allocates it to other users. Simulation results show that the proposed improved CHC algorithm additionally increases the fairness and sector throughput.

2.6 GHz 대역에서 M-WiMAX OFDMA/TDD 시스템과 WCDMA FDD 시스템간의 상호 간섭 분석 Part I : SISO 시스템에서의 상호 간섭 분석

고상준,왕우붕,장경희,Ko, Sang-Jun,Wang, Yu-Peng,Chang, Kyung-Hi 한국통신학회 2007 韓國通信學會論文誌 Vol.32 No.6a

본 논문에서는 2.6 GHz 대역에서 WCDMA (Wideband Code Division Multiple Access) 시스템과 M-WiMAX (Mobile-Worldwide Interoperability for Microwave Access) 시스템 모두 SISO (Single Input Single Output) 만을 적용한 상태에서, 상호 시스템 간에 미치는 간섭의 영향을 분석한다. 간섭이 발생하는 경우는 각 시스템 별로 네 가지로써, 총 여덟 가지의 경우가 존재한다. 그 중에서도 간섭원의 하향링크가 피간섭원의 상향링크에 미치는 간섭의 크기가 가장 심각한 경우임을 밝히며, 간섭의 영향을 최소화하기 위해 여덟 가지 경우 모두에 5MHz 의 보호대역을 적용한다. 특히 M-WiMAX 시스템이 피간섭원인 경우가 WCDMA 시스템이 피간섭원인 경우에 비해 더 많은 간섭이 발생하며, 이는 두 시스템간의 최대 송신 전력의 차이가 주된 원인으로 작용한다. 본 논문에서는 실질적인 상황과는 다르게 Spectrum Mask 내에 간섭원에 해당되는 시스템의 송신전력이 가득 채워져 있는 경우로 가정하였기 때문에, 보다 엄격한 Emission Mask를 사용하고 실질적인 시스템 간 간섭분석의 Worst-case 결과로 볼 수 있다. In this paper, we analyze the adjacent interference between WCDMA and M-WiMAX systems in the 2.6GHz Band under the SISO (Single Input Single Output) configuration. The interference scenarios are characterized into 8 scenarios with different victim and interfering links. Among the 8 scenarios, we find that the most performance loss is observed in the scenarios of victim uplink suffering interference from downlink in both systems. Besides, guard band is applied to mitigate the adjacent interference in all the scenarios. Especially, we reveal that M-WiMAX system is much more sensitive to adjacent interference than WCDMA system due to the lower transmission power. In this paper, we consider the worst interference environment, where interferers always transmit with the maximum power, a loose spectrum mask is adapted, and no additional channel fitters are equipped in both systems.

802.16e OFDMA/TDD 셀룰러 시스템의 성능 최적화를 위한 부채널과 전송전력 결합 할당 알고리즘 - Part II : 상향링크에서 Channel Sounding을 통한 부채널 할당 및 사용자의 수율에 따른 초기전송전력 결정 알고리즘

고상준,장경희,김재형,Ko, Sang-Jun,Chang, Kyung-Hi,Kim, Jae-Hyeong 한국통신학회 2007 韓國通信學會論文誌 Vol.32 No.9a

본 논문에서는 802.16e OFDMA/TDD 셀룰러 시스템에서 Sector Throughput과 Fairness를 향상시키기 위한 상향링크 동적자원할당 알고리즘을 제안한다. 제안된 알고리즘을 설명하기에 앞서 상하향링크 채널 정보의 차이를 언급하고, Round-robin 알고리즘에 사용자의 위치에 따라 할당 받을 수 있는 부채널 수를 제한하는 기존의 FLR 알고리즘과 전송전력 최소화 또는 전송률 최대화 Inner Closed-loop Power Control 알고리즘을 적용함으로서 10% 정도의 Throughput과 공평성 측면에서 높은 성능 향상을 볼 수 있다. 또한 상향링크 채널 사운딩을 통한 상향링크 채널 정보를 이용하여 FASA 알고리즘을 수행함으로써 FLR 을 적용한 Round-robin에 비하여 31.8%의 Sector Throughput이 향상되었다. User Selection, 부채널 할당 알고리즘, 전력할당 알고리즘과 Simulation Methodology 등은 Part I 논문에서 이미 언급한 바와 같다. In this paper, we propose an uplink dynamic resource allocation algorithm to increase sector throughput and fairness among users in 802.16e OFDMA TDD system. In uplink, we address the difference between uplink and downlink channel state information in 802.16e OFDMA TDD system. The simulation results show that not only an increment of 10% of sector throughput but higher level of fairness is achieved by round-robin using the FLR and the rate / margin adaptive inner closed-loop power control algorithm. The FLR algorithm determines the number of sub-channels to be allocated to the user according to the user's position. Also, we get 31.8% more sector throughput compared with the round-robin using FLR by FASA algorithm using uplink channel state information. User selection, sub-channel allocation, power allocation algorithms and simulation methodology are mentioned in Part I.

눈물주머니에 발생한 연소형 황색육아종 1예

고상준,김상덕,Sang Jun Ko,Sang Duck Kim 대한안과학회 2012 대한안과학회지 Vol.53 No.2

Purpose: To report a rare case of juvenile xanthogranuloma in the lacrimal sac. Case summary: An 8-year-old female presented to our hospital with epiphora and palpable mass on the left medial canthal area. As a symptom, a sticky and bloody discharge through the punctum had begun on occasion 3 months previously. When pressure was applied on the left medial canthal area, a mucoid discharge through the punctum occurred, and a solid mass was palpable. The mass localized in the lacrimal sac and upper nasolacrimal duct was observed on orbit CT. No invasion into the surrounding tissue was present. The authors of the present study decided to perform endonasal dacryocystorhinostomy, and subsequently a skin-colored mass was found in the lacrimal sac. The histopathological and immunohistochemical diagnosis was histiocytic proliferation, compatible with juvenile xanthogranuloma. Six months later, the patient complained of epiphora recurrence with palpable mass on medial canthal area. The tumor recurrence was confirmed with enhanced orbit CT finding 14 months after the first surgery. A second surgery using endonasal dacryocystorhinostomy was performed to remove the mass. J Korean Ophthalmol Soc 2012;53(2):348-352

200W급 SPMSM의 슬롯형 및 슬롯리스형 출력밀도 비교에 관한 연구

고상준(Sang-Jun Ko),이강석(Gang Seok Lee),채수황(Soohwang Chae),김승주(Seung-Joo Kim),이주(Ju Lee) 대한전기학회 2018 대한전기학회 학술대회 논문집 Vol.2018 No.-

창조성 신장을 위한 효과적인 발문수업

고상준 ( Sang Jun Ko ) 창조교육학회 2010 창조교육논총 Vol.12 No.-

A creativity inducing class is one that creates a comfortable, relaxing learning environment to form close relationships between teachers and students as well as among students themselves. It should encourage the sharing of ideas and the discussion of problems for the proper solutions. For instance, it is necessary to let students have enough opportunities to discuss the lessons with teachers and other classmates through some questions like ``What do you think is the most important aspect of this lesson?``, ``Does the same result come out every time we perform this experiment?`` etc. In this interactive class, the number of students who express their opinions voluntarily with confidence has increased. Not only do they express their opinions but also come up with questions regarding the matters discussed in class. They are able to prove their tentative theories through scientific debates. There has also been some changes in student interest in lessons and participation in the class. There has been significant growth in scientific knowledge. Most of all, the greatest achievement attained in this class is that the students have developed more confidence in themselves. The effects were influenced by the 5 step teaching method 1) The students` enthusiasm for class. 2) The teachers` passion for sharing their knowledge with their students. 3)Teachers` open-minded attitudes towards students, and an open communication line between teachers and students. 4) Maintain a positive way of thinking and behaving. 5) Formation of confidence like ``I can do it``. 6) Creative ways of thinking and creating new ideas from mistakes.

창조적 인간교육을 통한 집단창조성 형성

고상준 ( Sang Jun Ko ) 창조교육학회 2014 창조교육논총 Vol.16 No.-

Nowadays, how collective intelligence or human creativity can be built up effectively for Media or Economy Creation has been a very significant issue. Studying the recent reports and the articles on Creativity, I have found that most of them are about Individual Creativity. However, it is very difficult to find out about good methods to make up Creative groups. Creative Groups require the cooperation of every individual so they are very valuable in our society. Creativity can be developed when an individual relates to a group or a community and participates in various social activities. For instance, it is necessary to let students have enough opportunities to discuss the lessons with teachers and other classmates through some questions like ``What do you think is the most important aspect of this lesson?``, ``Does the same result come out every time we perform this experiment?`` etc. In this interactive class, the number of students who express their opinions voluntarily with confidence has increased. Not only do they express their opinions but also come up with questions regarding the matters discussed in class. There has been significant growth in scientific knowledge. Most of all, the greatest achievement attained in this class is that the students have developed more confidence in themselves.

OFDMA 시스템에서 효율적인 자원할당과 상향링크 궤환 정보 축소를 위한 FBL (Flexible Block-wise Loading) 알고리즘

선태형,고상준,장경희,황성현,송명선,김창주,Sun, Tae-Hyung,Ko, Sang-Jun,Chang, Kyung-Hi,Hwang, Sung-Hyun,Song, Myung-Sun,Kim, Chang-Joo 한국통신학회 2007 韓國通信學會論文誌 Vol.32 No.6a

다중 사용자를 위한 OFDM 시스템은 열악한 무선 전송 환경에서도, 고품질, 높은 신뢰성 통신을 제공하기 위해 각 사용자의 채널환경에 따른 적절한 변조방식과 코딩율을 선택하는 adaptive modulation and coding (AMC)가 사용된다. 기지국에서 AMC기술을 사용하여 각 단말기를 최상의 성능으로 동작시키기 위해서는, 각 단말기의 하향링크에 대한 모든 부반송파 채널 정보를 필요로 한다. 그러나 실질적인 시스템 환경 하에서는 한정된 상향링크 자원으로 인하여 모든 부반송파의 채널 정보를 전송하는 것은 현실적으로 적합하지 않다. 본 논문에서는 AMC 시스템의 성능을 최적화 시키기 위하여 기존의 시스템보다 더 적은 양의 Channel Quality Indicator (CQI) 피드백을 사용하는 새로운 기술을 자원할당을 위한 Flexible Block-wise Loading (FBL) 알고리즘과 결합한다. 제안된 알고리즘은 기존의 고정 부반송파 그룹 할당에서 탈피하여 가변적으로 부반송파 그룹의 크기를 조절하여 할당함으로서 sector throughput과 outage probability의 성능을 향상시킨다. OFDM Systems for multi-user use adaptive modulation and ending (AMC) which is a method that selects suitable modulation order and code rate depending on channel state of each user. Using AMC, OFDM system can provide high quality and reliable communication. Base station using AMC scheme requires downlink channel information of each terminal to operate optimality. However, under practical system environment, it is unsuitable to transmit all channel information because uplink bandwidth of the system is limited. In this paper, we propose a flexible block-wise loading (FBL) algorithm combined with a novel CQI feedback scheme with reduced number of required bits to optimize the performance of AMC system. Proposed algorithm allocates sub-carrier groups dynamically to improve the sector throughput and outage probability performance.