LDPC부호화를 적용한 영상통신시스템설계

최태식,공형윤,최원호 울산대학교 2001 공학연구논문집 Vol.32 No.1

다양한 멀티미디어 통신이 발달함에 따라 채널부호화를 사용하여 오류를 정정하는 기술이 발달되어 왔다. 본 논문에서는 압축영상의 전송에서 LDPC 부호화를 이용하여 영상통신채널에서의 오류를 복원하고, 영상을 재구성할 수 있는 영상통신시스템을 제안한다. 제안된 영상통신시스템은 패리티검사행렬을 사용하여 가장 많은 오류를 발생하는 열과 가장적은 오류를 발생하는 열을 교환하는 방식을 사용하였고, 가우시안 노이즈를 가지는 통신채널의 신호 대 잡음비는 0dB에서 4dB의 범위로 설정하였다. 패리티 검사 행렬이 작은 경우 제시한 교환 방식을 사용하였을 때 사용하지 않은 경우보다 BER 성능이 우수함을 확인하였으며, 영상을 재구성한 경우에도 PSNR 성능이 우수함을 확인할 수 있었다. As a various multimedia communication has been developed, the error correction technique using the coding method was improved. In this paper, an image communication system using the LDPC decoding method for restoring the error and reconstructing the image in the image compression transmission is proposed. The proposed system has a parity check matrix that can alternate the least occurring error column with the most occurring error column. The signal to noise ratio of a communication channel with the gaussian noise was determined the range between 0dB 4dB. When a parity check matrix was a small size, the system's BER efficiency with the parity check alternating method was better than the parity check without it. Also in reconstructing image, the proposed system's PSNR efficiency was superior to system without alternating method.

3-차원 블록인터리버기법의 터보코드를 이용한 영상통신시스템설계

최태식,공형윤,최원호 울산대학교 2001 공학연구논문집 Vol.32 No.1

본 논문에서는 3-차원 블록인터리버기법의 터보코드를 사용하여 무선 통신 환경 하에서 효과적으로 전송할 수 있는 영상 통신 시스템을 제안한다. 웨이브릿 변환과 벡터양자화를 영상의 압축알고리즘에 사용하였으며, 무선통신시스템의 코딩방식 중 하나인 터보코드를 사용하여 압축영상데이터의 통신에 사용하였다. 터보코드의 성능은 데이터율, 부호기의 구속장의 길이, 복호 방식, 순환복호의 횟수, 인터리버의 종류 및 블록크기에 의존되어 진다. 같은 비트 크기에서의 2차원 블록인터리버보다 비트간의 거리를 크게 하는 3차원 인터리빙알고리즘을 적용한 시스템이 영상통신에서 높은 성능을 얻었다. 컴퓨터 시뮬레이션을 이용하여 3차원 블록인터리버의 성능을 압축된 영상과 가우시안 잡음 채널 환경 하에서 비교분석 하였다. In this paper, an image communication system that can effectively work in wireless communication environment is proposed. The wavelet transform and the vector quantization are used to the compress images. The turbo code that is one of the coding methods in wireless communication is used for the compressed image data communication. The efficiency of turbo code depends on the data rate, the constraint length, the decoding algorithm, the number of decoding iteration, the type of interleavers and the block size. The system with 3-D interleaving algorithm whose bit distance is longer than the 2-D block interleaver in the same size had the higher performance in image transmission. To verify the performance of the proposed method, computer simulation was performed in Gaussian noise model.

[논문]부산지역 초고충 주상복합아파트의 문제점 및 개선방안 연구

최열,장원호,공윤경 釜山大學校 都市問題硏究所 2004 都市硏究報 Vol.16 No.-

The functional segregation of urban area and space was a priciple of urban development and planning up to now. However, there had been many problem such as decline of residential function in CBD and traffic congestion, etc. due to job-housing mismatch. The mixed-use development could be alternatives to address these problems. This paper is to examine how super high-rise mixed-use dwelling have been developed in Busan based on actual projects and address the problem and solutions about location, development type, mixed-use development through the questionnaire survey. The following are the results of this study. First, super high-rise mixed-use building have been built near Seomyun and new residential development area rather than to restore old CBD that the population relatively is decreased Second, without considering the locational characteristics of super high-rise mixed-use buildings, the housing type like general apartment complex is mostly distributed. Finally, the mitigation of the building criteria for multi-family housing in commercial zoning can be uncomfortable to actual residents.

정신재활 치료가 정신분열병 환자의 재발율, 입원횟수, 입원일수 그리고 치료 경비에 미치는 효과 : 2년 추적조사 연구

조진석,공지현,김진원,심경순,하준선,김철권,강동호,장정희,변원탄 大韓神經精神醫學會 1998 신경정신의학 Vol.37 No.5

목 적 : 사회기술훈련, 환자교육, 가족교육, 집단치료, 예술치료, 작업치료와 같은 포괄적인 정신재활 치료를 약물치료와 병행할 경우 약물치료만 시행할 때에 비해 정신분열병 환자의 재발율, 입원횟수, 입원일수, 직접 치료경비 등에 어떤 효과가 있는 지를 알아보기 위함이다. 연구방법 : 1993년 9월부터 1995년 2월까지 양산 신경정신병원의 폐쇄병동에서 퇴원한 20∼35세 사이의 정신분열병 환자 173명을 대상으로 46명에게는 6개월동안 정신재활 치료를 시행하였고 127명에게는 통상적인 외래치료만 시행한 후 연구시작 시점을 포함하여 2년동안 양군에 속한 환자들을 대상으로 재발율, 입원횟수, 입원일수, 직접 치료경비 등을 1년 단위로 추적 조사하였으며, 연구시작 시점을 기준으로 전과 후의 매년 평균 입원횟수, 입원일수, 직접 치료경비도 서로 비교하였다. 결 과 : 정신재활 치료를 약물치료와 병행할 경우 약물치료만 시행할 때에 비해 재발율, 입원횟수, 입원일수, 직접 치료비용이 현저히 감소되었다. 그리고 정신재활 치료를 받은 군에서는 치료 전에 비해 치료 후에 재발율, 입원횟수, 입원일수, 직접 치료비용이 유의하게 감소하였지만 통상적인 외래치료만 받은 군에서는 치료 전과 후간에 유의한 변화를 보이지 않았다. 결 론 : 정신분열병 환자들에게 정신재활 치료를 약물치료와 병행할 경우 약물치료만 시행할 때에 비해 환자의 임상적 경과를 호전시킬 뿐 아니라 가족의 경제적 부담도 줄일 수 있다. Objective : We evaluated the clinical efficacy of a comprehensive psychiatric rehabilitation of schizophrenia, including family psychoeducation, patient education, social skills training, group psychotherapy, art therapy, and occupational therapy. Method : From September 1993 to February 1995, 173 chronic schizophrenics who met DSM-IV criteria and were discharged from a locked ward were assigned into the psychiatric rehabilitation service group(psychiatric rehabilitation group, n=46) or the customary out-patient service group(out-patient group, n=127) prospectively, but not randomly. Assignment was based on preferences of patients and their relatives, Each subject included in the psychiatric rehabilitation group received twice weekly patient education, social skills training, family psychoeducation, group psychotherapy, art therapy, occupational therapy and maintenance chemotherapy during a 6-month period. Those in the out-patient group received individual supportive psychotherapy and maintenance chemotherapy according to their clinical needs for 10-20 minutes once per week. After entry into the study, all subjects were assessed for the number of readmission, days of hospitalization, and the direct treatment costs through the first and second year of follow-ups. These outcome variables were also compared pre-and post-2 years at the time point of entry into the study. Aftercare chemotherapy on a weekly to monthly basis continued for the remainder of the two year follow-up period. Results : With regard to the mean number of hospital admissions per year, the mean days of hospitalization per year, and the direct treatment costs per year, the psychiatric rehabilitation group had significantly decreased all clinical outcomes 2 years after compared with before receiving psychiatric rehabilitation. But there were no significant differences in the all clinical outcomes between before and after study intake in the out-patient group. For the number of relapse regardless of drug compliance, 4 patients(9%) during first year and 14 patients(30%) during second year were relapsed in the 46 subjects of the psychiatric rehabilitation group. In contrast, 75 patients(59%) during first year and 90 patients (71%) during second year relapsed in the out-patient group. When considering the effect of drug noncompliance to relapse, 4(9%) and 14 patients(30%) were relapsed while on medication respectively during the first and second year in the 46 of the psychiatric rehabilitation group, vs. 27(34%) of 79 patients on medication during the first year and 31(46%) of 68 patients on medication during the second year were relapsed in the out-patient group. Conclusions : These results indicate that the comprehensive psychiatric rehabilitation can be useful therapeutic intervention both to improve the clinical outcomes of schizophrenic patients and to reduce the economical burden of their relatives.

The Clinical Features of Korean Patients with Duane`s Retraction Syndrome

( Won Ho Park ),( Dae Hyun Son ),( Sang Won Yoon ),( Seung-hee Baek ),( Sang Mook Kong ) 대한안과학회 2005 Korean Journal of Ophthalmology Vol.19 No.2

Purpose: To describe the clinical features of Duane`s retraction syndrome (DRS) in Korean patients. Methods: We retrospectively analyzed the 78 DRS cases that presented to our department between 1995 and 2004. The clinical features investigated included sex distribution, laterality, type of presentation, deviation in primary position, anomalous vertical movements, face turn, amblyopia and anisometropia. Results: There were 38 (48.7%) affected males and 40 (51.3%) females. Left eye predominance (83.3%) was observed, as was typeⅠ presentation (85.9%). Orthotropia was found to be the most common primary position in 46 cases (59.0%). Face turn in unilateral DRS was noted in 13 patients (17.1%). There were 6 cases (7.7%) with anisometropia and 4 (5.1%) with amblyopia. Conclusions: The clinical manifestations of DRS in our study were different from those of equivalent Caucasian studies yet similar to those previously reported for Asian groups. Racial and regional differences were noted, for which further research is needed to elaborate the reasons and mechanisms.

Design and Fabrication of Miniaturized Optical Chopper Operated by Electromagnetic Actuation

( Ho Won Kim ),( Seong Ki Min ),( Young Chan Choi ),( Seong Ho Kong ) 한국센서학회 2014 센서학회지 Vol.23 No.3

An existing infrared (IR) analysis system is generally composed of infrared source, IR focusing lenses, IR detector, and optical chopper. An optical chopper is widely used in combination with lock-in amplifier to improve the signal-to-noise ratio by periodically interrupting incident light beam. During recent years, a few researches on miniaturized optical chopper have been reported to apply to microscaled optical systems. In this paper, a micro optical chopper operated by electromagnetic actuation is proposed and applied to a miniaturized micro-scaled optical system operating in IR spectral range. Additionally, the fabrication method of the proposed micro chopper is demonstrated. The proposed micro optical chopper is composed of the polydimethylsiloxane (PDMS) membrane, solenoid, and permanent magnet. The permanent magnet is bonded on the PDMS membrane using an ultraviolet-activated adhesive. The operation of the chopper is based on the attractive and repulsive forces between permanent magnet and solenoid induced by an electrical current flowing through the solenoid. The fabricated micro optical chopper could operate up to 200 Hz of frequency. The maximum operating distance of the chopper with 7mm diameter membrane was 750 μm at 100 Hz of frequency.

The Effect of a Honeycomb Core on the Mechanical Properties of Composite Sandwich Plates

Kong, Cheol Won,Eun, Se Won,Park, Jae Sung,Lee, Ho Sung,Jang, Young Soon,Yi, Yeong Moo,Cho, Gwang Rae Trans Tech Publications, Ltd. 2005 Key Engineering Materials Vol.297 No.-

<P>When comparing composite sandwich analysis with an exact solution, the results of finite element modeling with an ANSYS shell 91 element agreed well with the exact solution. The practical applications of the shell 91 element are demonstrated with a four-point bend test conducted on sandwich beam specimens. The specimens comprised carbon/epoxy fabric face sheets and a honeycomb core. Two kinds of honeycomb cores were used to fabricate the composite sandwich specimens: an aluminum one and a glass/phenolic one. The predictions with the shell 91 element were also agreed well with the experimental results. A variety of tests was conducted; namely, a long beam flexural test, a short beam shear test, a flatwise tensile test, a flatwise compression test and an edge compression test. The sandwich plate with the aluminum honeycomb core had a specific bending stiffness that was 1.7 to 2.0 times higher than that of the sandwich plate with the glass/ phenolic honeycomb core.</P>

Cationic lipid-coated gold nanoparticles as efficient and non-cytotoxic intracellular siRNA delivery vehicles.

Kong, Won Ho,Bae, Ki Hyun,Jo, Sung Duk,Kim, Jee Seon,Park, Tae Gwan Kluwer Academic/Plenum Publishers 2012 Pharmaceutical research Vol.29 No.2

<P>Cationic lipid-coated gold nanoparticles were developed for efficient intracellular delivery of therapeutic siRNA.</P>

Stage Migration Effect on Survival in Gastric Cancer Surgery With Extended Lymphadenectomy: The Reappraisal of Positive Lymph Node Ratio as a Proper N-Staging

Kong, Seong-Ho,Lee, Hyuk-Joon,Ahn, Hye Seong,Kim, Jong-Won,Kim, Woo Ho,Lee, Kuhn Uk,Yang, Han-Kwang Lippincott Williams Wilkins, Inc. 2012 Annals of surgery Vol.255 No.1

OBJECTIVE:: The purpose of this study is to analyze the relationship between the number of examined lymph nodes (NexLN) and survival in gastric cancer and to determine whether the metastatic/examined lymph node ratio (LN ratio) system can compensate for the shortcomings of the UICC/AJCC staging. METHODS:: Prospective data of 8949 primary T1-T4a gastric cancer patients who underwent curative surgery were reviewed. The patients were stratified by T-stage and grouped according to NexLN; 1 to 14 exLN denoted the first group and every subsequent 10 LNs thereafter. Numbers of LN and 5-year survival rates were analyzed according to NexLN. “The NR-staging system” was generated using 0.2 and 0.5 as the cut-off values of LN ratio and then compared with UICC/AJCC stages. RESULTS:: The proportion of advanced N-stage increased with NexLN. Survival and the LN ratio were constant regardless of NexLN when combining all N0-N3b patients, however, T2/3 and T4a patients showed an increasing tendency toward survival in N1/2 and N3a as NexLN increased, mainly due to a stage migration effect. The LN ratio system showed better patterns of distribution of the LN stage and survival graph. The power of the differential staging of the LN ratio system was fortified with higher NexLN. CONCLUSION:: The relationship between NexLN and survival is probably affected by stage migration in a high-volume gastric cancer center. The LN ratio system could be a better option to compensate for this effect, and the value of the prognosis prediction in this system increases with a higher NexLN.

Multimerized siRNA Cross-linked by Gold Nanoparticles

Kong, Won Ho,Bae, Ki Hyun,Hong, Cheol Am,Lee, Yuhan,Hahn, Sei Kwang,Park, Tae Gwan American Chemical Society 2011 Bioconjugate chemistry Vol.22 No.10

<P>In this study, siRNAs terminated with thiol groups were multimerized and cross-linked using ∼5 nm gold nanoparticles (AuNPs) via Au–S chemisorption that can be intracellularly reduced. AuNPs immobilized with single-stranded antisense siRNA were assembled with those with single-stranded sense siRNA via complementary hybridization or assembled with those with single-stranded dimeric sense siRNA. The multimerized siRNA cross-linked by AuNPs showed increased charge density and enhanced enzymatic stability, and exhibited good complexation behaviors with a polycationic carrier, linear polyethylenimine (L-PEI). The resultant multi-siRNA/AuNPs/L-PEI polyelectrolyte complexes exhibited far greater gene silencing efficiencies of green fluorescent protein (GFP) and vascular endothelial growth factor (VEGF) compared to naked siRNA complexes. They could also be visualized by micro-CT imaging. The results suggest that AuNP-mediated multimerization of siRNAs could be a rational approach to achieve both gene silencing and imaging at a target tissue simultaneously.</P><P><B>Graphic Abstract</B> <IMG SRC='http://pubs.acs.org/appl/literatum/publisher/achs/journals/content/bcches/2011/bcches.2011.22.issue-10/bc200172p/production/images/medium/bc-2011-00172p_0006.gif'></P>