Immediate Vitrectomy for Acute Endophthalmitis in Patients with a Visual Acuity of Hand Motion or Better

Jaemin Kim(Jaemin Kim),Hyoung Seok Kim(Hyoung Seok Kim),Su Jin Yoo(Su Jin Yoo),Moon Jung Choi(Moon Jung Choi),Youngju Lew(Youngju Lew),Jong Woo Kim(Jong Woo Kim),Han Joo Cho(Han Joo Cho) 대한안과학회 2022 Korean Journal of Ophthalmology Vol.36 No.5

Purpose: To determine the efficacy of immediate pars plana vitrectomy as the primary treatment for acute endophthalmitis in patients with a visual acuity (VA) of hand motion (HM) or better. Methods: A total of 149 patients who were referred to a single center for acute endophthalmitis after cataract surgery over the 13-year study period were retrospectively analyzed. Only patients presenting with a VA of at least HM were included. Patients were initially treated with either primary vitrectomy or intravitreal antibiotic injection alone, and their visual outcomes and reintervention rates after initial treatment were compared. Results: There was no significant difference in the proportion of good (final VA ≥20 / 40) and poor (VA ≤ counting finger) visual outcomes between the groups. However, subgroup analysis of patients with a VA of HM (92 eyes) showed that the incidence of reintervention (14 of 72 eyes [19.4%] vs. 9 of 20 eyes [45.0%]) and poor visual outcomes (10 of 72 eyes [13.9%] vs. 8 of 20 eyes [40.0%]) were lower after prompt vitrectomy than after intravitreal antibiotic injection alone (p = 0.019 and p = 0.022, respectively). For those with a VA of at least counting finger, no significant difference was observed between the groups. Conclusions: For patients with endophthalmitis presenting with a VA of HM, performing a prompt vitrectomy reduced the incidence of reintervention and poor visual outcomes than the administration of intravitreal antibiotics alone. Our results suggest that primary vitrectomy for patients with endophthalmitis presenting with a VA of HM could be more beneficial than intravitreal antibiotic injection alone.

A Complementary Approach to Strategic Information Systems Planning

Jaemin Han,Young J. Shin,Taesoo Moon,Jeong-Sik Yang 대한산업공학회 1990 대한산업공학회 춘계학술대회논문집 Vol.1990 No.5

A REVISIT TO HOPFIELD MODEL IN TSP

Jaemin Han,Shijoong Sung 대한산업공학회 1995 대한산업공학회 춘계학술대회논문집 Vol.1995 No.4

A Complementary Approach to Strategic Information Systems Planning

Han, Jaemin,Shin, Young J.,Moon, Taesoo,Yang, Jeong-Sik 한국경영과학회 1990 한국경영과학회 학술대회논문집 Vol.- No.1

The information revolution is sweeping through the global economy. The strategic significance of the information and information technology have been somewhat underestimated. Now they are transforming the structure of competition. Information technology must be applied to improve and sustain an organization's competitive advantage. The successful implementation of information technology is dependent on the effectiveness of information systems planning. However, the selection of right methodology still remains an open question. This paper describes the existing methodologies for information system planning. A complementary approach to strategic information systems planning, which was developed for a steel company, is suggested. The approach attempts to combine Business Systems Planning of IBM and Critical Success Factors Analysis for effective information systems planning. Although this approach is in the experimental stage it looks to be of benefit to large organizations which require information planning for managerial level.

Efficient Weight Initialization Method in Multi-Layer Perceptrons

Han, Jaemin,Sung, Shijoong,Hyun, Changho 한국경영과학회 1995 한국경영과학회 학술대회논문집 Vol.- No.2

Back-propagation is the most widely used algorithm for supervised learning in multi-layer feed-forward networks. However, back-propagation is very slow in convergence. In this paper, a new weight initialization method, called rough map initialization, in multi-layer perceptrons is proposed. To overcome the long convergence time, possibly due to the random initialization of the weights of the existing multi-layer perceptrons, the rough map initialization method initialize weights by utilizing relationship of input-output features with singular value decomposition technique. The results of this initialization procedure are compared to random initialization procedure in encoder problems and xor problems.

Asymmetric diversity modulation scheme in wireless fading relay channels

Jaemin Han,Eunsung Oh,Hyungsik Ju,Daesik Hong IEEE 2009 IEEE TRANSACTIONS ON WIRELESS COMMUNICATIONS Vol.8 No.7

<P>In this paper, we propose an asymmetric diversity modulation (ADM) scheme for a single-source relay system that utilizes the relay's higher transmission ability as a form of diversity. To achieve this, the proposed method transmits multiple source bits over a high-order modulating relay as a way to provide additional time diversity. The spatial and time diversity then undergo 'bit'-based combining at the destination. Using the proposed 'bit'-based channel combining method, we derive the theoretical bit error rate (BER) for such a system. Moreover, we investigate the fact that the proposed scheme shows a performance trade-off between bit power and time diversity resulting from the reduced bit power caused by a high-order modulating relay.</P>

AN ALGORITHM FOR RESOLUTION OF RESOURCE CONFLICTS IN SCHEDULING

HAN, JAEMIN 한국경영과학회 1992 經營 科學 Vol.9 No.1

A two phase heuristic algorithm has been developed for the resolution of resource conflicts in a single project scheduling problem. Phase 1 of the algorithm generates a feasible schedule by repairing resource conflicts. Phase 2 finds local improvements in the schedule found in phase 1. Then, the algorithm has been applied to multi project and job shop scheduling. Computational results are compared with those of dispatching procedures. Index Terms-disjunctive constraints, heuristic algorithm, project scheduling, job-shop scheduling

주파수 가간섭성을 이용한 피드백을 사용하는 하향 링크 OFDMA 시스템에서의 동적 자원 할당 방법

한재민(Jaemin Han),오은성(Eunsung Oh),한승엽(Seungyoup Han),주형식(Hyungsik Ju),홍대식(Daesik Hong) 대한전자공학회 2007 대한전자공학회 학술대회 Vol.2007 No.11

In this paper, we propose a new DCA (Dynamic Channel Allocation) in DL (Downlink) OFDMA (Orthogonal Frequency Division Multiple Access). The proposed DCA scheme exploits each user"s coherence bandwidth in a multi-path environment, resulting in the better multi-user diversity performance than the amplitude craving greedy (ACG) method and Modified ACG (M-ACG) with the reduced feedback overhead.

네트워크 오퍼레이터 비즈니스 모델

한재민(Jaemin Han),김재영(Jaeyoung Kim) 한국인터넷전자상거래학회 2015 인터넷전자상거래연구 Vol.15 No.1

The complexity of business relationship has been increased as information technology continuously developed. Because of this, business organization must propose sophisticated values to the customer through the analysis of customer needs, business operation, and market competition. The network operator as a business model tries to overcome limitation of structural and behavior perspectives in traditional network theories. In this paper, the concept of network operator offers explanation of comprehensive view based on systematic approach. Through case study, iPhone entered smart phone industry with an earth-break brand in 2007. After a few years, iPhone becomes a market leader who creates tremendous revenue to compare with competitors through a network operator business model. The iPhone captured latent business opportunity in competition fixation and market governance in telecommunication industry satisfying customer desires of data communication. Therefore, the iPhone business model converts business opportunity as revenue taking role as a network operator. The network operator business model provides a conceptual establishment to understand change of competitive environment which IT development brought. Network operator business model explains how business organization achieve strategic value in competition environment which regards issues that who brings what values to whom and how to generate revenue in terms of network operation perspectives.

자동차용 브레이크 디스크의 부식으로 인한 마찰특성의 변화에 대한 연구

한재민(Jaemin Han),조근형(Keun Hyung Cho),장호(Ho Jang),김성진(Seong Jin Kim),이재영(Jae-Young Lee),박현달(Hyun-Dal Park) 한국트라이볼로지학회 2005 한국트라이볼로지학회 학술대회 Vol.2005 No.11

Corrosion tests of discs were carried out in an environmental chamber, simulating in-vehicle situation, and torque variation during braking was measured using a single-end brake dynamometer. A friction model was introduced to confirm the pattern of torque variation. Ingredients in a friction material were substituted to series of springs and dashpots in this model. The velocity of the brake disc and the strength of the friction layer representing the existence of corrosion layer ware calculated as a variable. Results showed that the friction film and moisture content strongly affected the amount of corrosion. The dynamometer results also showed that the existence of the corrosion layer affected brake torque variation, and this result was confirmed by the friction model. The model showed that the amount of the torque variation increased when the corrosion layer existed and when the amount of ingredients with high stiffness increased at the fixed velocity. This suggested that the strength of corrosion layer and the transition of iron oxide particles were crucial factors for the corrosion induced torque variation.