DVB-S2 기반 LDPC 복호기의 멀티레벨 변조 방식 적용을 위한 디맵핑 알고리즘

정지원,정진희,김민혁,Jung Ji-Won,Jeong Jin-Hee,Kim Min-Hyuk 한국전자파학회 2006 한국전자파학회논문지 Vol.17 No.7

DVB-S2 표준안에서는 다양한 부호화율과 그에 따른 다양한 변조 방식을 지원한다. 따라서 본 논문에서는 LDPC에 8 PSK 이상의 다치 변조 방식 적용을 위해 수신단에서 비트 분리 방법을 제시한다. 수신된 I, Q 심볼만을 이용하여 세 비트 이상의 비트를 분리하기 위한 LLR 방식에 기초를 하여 LLR 방식의 단점인 복잡도를 개선하기 위해 Euclidean, MAX, Sector 방식을 제시하였다. DVB-S2 offers various coding rate and modulation schemes. Therefore this paper proposes bit split methods to applying to multilevel modulation. Log-likelihood ratio method splits multilevel symbols to soft decision symbols using the received in-phase and quadrature component based on Gaussian approximation. However it is too complicate to calculate and to implement hardware due to exponential and logarithm calculation. Therefore this paper presents Euclidean, MAX and Sector method to reduce the high complexity of LLR method.

한국인 나이관련황반변성 환자의 우울 및 불안에 대한 조사 및 그 영향에 대한 고찰

정지원,문연성,Ji Won Jung,Yeon Sung Moon 대한안과학회 2012 대한안과학회지 Vol.53 No.6

Purpose: To examine the degree of depression and anxiety in Korean patients with age-related macular degeneration (AMD) and to evaluate the influence of mood disturbance on patient’s treatment satisfaction and compliance. Methods: Forty-four patients with AMD and thirty-three controls comprised the study populations. Patients and controls rated themselves on the Korean Beck Depression Inventory (BDI) and Beck Anxiety Inventory (BAI). The effect of mood disturbance on the patient’s satisfaction and compliance was evaluated. Results: The depression and anxiety scores were significantly higher in patients with AMD. The mood disturbance was negatively correlated with the patient’s satisfaction and compliance. 14 patients (31.8%) were lost to follow-up 1 year later. The depression and anxiety scores of these patients were higher than those of remaining thirty patients. Conclusions: Depression and anxiety of patients with AMD affect on patient’s satisfaction and compliance. So recognition and management of mood disturbance may help improving visual function and maintaining quality of life in patients. J Korean Ophthalmol Soc 2012;53(6):792-800

가족기반연구에서 형매정보를 이용한 유전적 연관성 분석방법의비교

정지원,이석훈,김순애,박미라,Jung, Ji-Won,Lee, Suk-Hoon,Kim, Soon-Ae,Park, Mi-Ra 한국통계학회 2010 Communications for statistical applications and me Vol.17 No.5

가족기반 유전연구에서 단일염기다형성(SNP) 및 일배체형(haplotype)을 이용한 질병-유전자간 연관성 분석은 주요 관심부분 중 하나이다. 이진형질인 경우 사용되는 고전적인 TDT(transmission/disequilibrium test)는 부/모/자의 유전정보를 모두 알 수 있을 때에 쓸 수 있다. 그러나 경우에 따라서는 부모의 유전자형에 대한 정보를 사용할 수 없을 수가 있는데, 치매등과 같이 늦게 발병하는 질환에서 이런 경우가 자주 발생한다. 부모의 유전자형을 모를 때 이를 대체할 수 있는 방법으로 형매(sib)의 유전정보를 이용하는 방법이 있다. 본고에서는 가족기반연구에서 형매의 유전정보를 이용하는 분석방법에 대해 고찰하고 모의실험을 통해 이들의 검정력을 비교하였다. Recently, disease-genetic association analyses using single nucleotide polymorphisms(SNPs) and haplotypes in family-based genetic study have come into the spotlight. In binary trait, the classic transmission disequilibrium test(TDT) can only be applied if genetic information of parents and their offspring is available. However, in case of diseases having a late age of onset such as dementia, the TDT cannot be applied due to the fact that parental genotype data are unavailable. For this reason, alternate methods using genetic sib information instead of parental genotype data are proposed. In this study, methods using genetic sib information are reviewed and power of analysis tests is also compared throughout simulation experiment.

Effect of stellate ganglion block on laryngopharyngeal reflux disease

정지원,Hye Jung Chun,이미순,Ki Ryang Ahn,Chun Sook Kim,Kyu Sik Kang,유시현,정진헌,김난설,서용한,Hyung Youn Gong,Yong Man Lee 대한마취통증의학회 2013 Korean Journal of Anesthesiology Vol.64 No.5

Background: Laryngopharyngeal reflux (LPR) disease has many symptoms such as globus pharyngeus, excessive throat clearing and hoarseness. The aim of this study was to investigate the effect of stellate ganglion block (SGB) in addition to proton pump inhibitors (PPI) on LPR. Methods: Fifty patients complaining of more than 3 typical LPR symptoms for over 3 months were enrolled in the study. The P group took PPI for 8 weeks. The SP group took PPI and interwent a series of 8 SGB procedure once a week during the period of treatment. The blocks were performed one at a time unilaterally on the right and left stellate ganglions by injecting 1% mepivacaine 6 ml. We evaluated the reflux symptom index (RSI) before treatment and following 4 weeks and 8 weeks of treatment in both groups. Results: After 4 weeks of treatment, the RSI of the P group decreased, but not significantly, to 16.6 ± 6.8 compared with the baseline value of 19.2 ± 2.7 (P = 0.093), whereas the RSI of the SP group decreased significantly to 9.8 ± 3.3 compared with the baseline value of 19.0 ± 4.7 (P = 0.000). After 8 weeks of treatment, the RSI of the P group decreased significantly to 13.7 ± 6.7 (P= 0.001) and the RSI of the SP group also decreased significantly to 7.7 ± 3.4 (P= 0.000). There were significant differences in the RSI between the two groups after 4 weeks (P = 0.000) and 8 weeks (P = 0.001) of treatment. Conclusions: The symptoms of LPR improved earlier when PPI therapy was combined with SGB compared with PPI therapy alone.

FTN 전송기법에서 최적의 필터 roll-off 값 및 탭수 설정

정지원,Jung, Ji-Won 한국정보전자통신기술학회 2015 한국정보전자통신기술학회논문지 Vol.8 No.2

본 논문은 인접 심볼 간의 간섭이 발생하지 않는 최대 데이터 전송률인 Nyquist rate 보다 빠르게 데이터를 전송하여 전송량을 증가시키는 FTN(Faster than Nyquist) 기법을 이용하여 최적의 필터 roll-off 값과 탭 수를 설정한다. FTN 신호 전송 시 발생하는 ISI(Inter-Symbol Interference)를 최소화하기 위해 LDPC부호를 기반으로 하는 터보 등화 모델을 적용하였으며, FTN 신호의 필터 roll-off 값과 탭 수에 따라 시뮬레이션하여 성능을 향상시키고 최적의 값을 설정하였다. In this paper, to increase the throughput for wireless communication, FTN methods that is faster than Nyquist rate are used recently. To improve performance, turbo equalization algorithms that iteratively exchange probabilistic information between soft Viterbi equalizer and LDPC decoder to minimize ISI are applied in this paper. In FTN transmission, the performance depends on roll-off value and number of tabs of SRRC(Square Root Raised Cosine) filter. Therefore, Based on simulation, this paper present optimal number of filter coefficient and tab for various ISI factor of ${\tau}$.

유전자형별 상대 위험도를 이용한 유전자-유전자간 상호작용 탐색

정지원,이재용,이석훈,박미라,Jung, Ji-Won,Yee, Jae-Yong,Lee, Suk-Hoon,Pa, Mi-Ra 한국통계학회 2011 응용통계연구 Vol.24 No.5

최근 유전학에서 주요 목표중 하나는 복합질환에 영향을 미치는 유전적 요인을 찾아내는 것이다. 유전자좌간의 상호작용이 있을 때에는 단일 유전자좌 분석으로는 이러한 목표를 달성하기 어려우므로, 유전자-유전자간 상호작용이나 유전자-환경인자간 상호작용분석을 고려할 필요가 있다. 자주 사용되는 MDR(multifactor dimensionality reduction)방법은 데이터를 고위험군과 저위험군으로 각각 병합하여 사용하므로 특정 유전자형에서 차이가 나는 경우에는 이를 찾아내기 어렵다. 본 연구에서는 이러한 점을 보완하도록 유전자형 조합에서의 대조군과 질환군의 상대위험도를 이용하여 유전자-유전자간 상호작용을 탐색하는 방법을 제안하였다. MDR 공개데이터와 8가지 유전모형으로부터 생성한 모의자료의 분석을 통해 방법의 유용성을 확인하였다. One of the main objects of recent genetic studies is to understand genetic factors that induce complex diseases. If there are interactions between loci, it is difficult to find such associations through a single-locus analysis strategy. Thus we need to consider the gene-gene interactions and/or gene-environment interactions. The MDR(multifactor dimensionality reduction) method is being used frequently; however, it is not appropriate to detect interactions caused by a small fraction of the possible genotype pairs. In this study, we propose a relative risk interaction explorer that detects interactions through the calculation of the relative risks between the control and disease groups from each genetic combinations. For illustration, we apply this method to MDR open source data. We also compare the MDR and the proposed method using the simulated data eight genetic models.

백내장 수술 후 서로 다른 임상 양상을 보인 스테노트로포모나스 말토필리아 안내염 2예

정지원,강행구,진희승.Ji Won Jung. MD. Haeng Ku Kang. MD. Hee Seung Chin. MD. PhD 대한안과학회 2012 대한안과학회지 Vol.53 No.1

Purpose: To report 2 different cases of postoperative endophthalmitis caused by Stenotrophomonas maltophilia after cataract surgery. Case summary: A 73-year-old male with diabetes mellitus developed severe pain in the right eye 2 weeks after cataract surgery. The patient was hospitalized with a diagnosis of infectious endophthalmitis, and vitrectomy was performed. Cultures of aqueous humor and vitreous aspirate revealed S. maltophilia. On day 30 after vitrectomy, his visual acuity had improved to 20/20 and there were no recurrences. A 61-year-old female with no significant past medical history was referred for uveitis or delayed onset endophthalmitis 30 days after cataract surgery. An anterior chamber tapping and cultures were performed. S. maltophilia and Aspergillus fumigatus were isolated. The patient received antibiotics and antifungal agents and her visual acuity improved to 20/25. Conclusions: S. maltophilia has been considered a life-threatening systemic opportunistic infection; however, the organism has recently been reported as an exogenous pathogen of endophthalmitis following cataract surgery. Herein, 2 different cases of S. maltophilia endophthalmitis after cataract surgery are presented and compared with previous case reports. J Korean Ophthalmol Soc 2012;53(1):161-167

이중분무의 중첩영역과 단일분무에서 액적의 거동 특성

정지원,차건종,김덕줄,Jung, Ji-Won,Cha, Keun-Jong,Kim, Duck-Jool 대한기계학회 2000 大韓機械學會論文集B Vol.24 No.10

The objectives of this study was to investigate the spray characteristics of single spray and twin spray in the overlap region such as mean axial velocity, mean radial velocity, mean droplet size and probability density function of droplet size. A phase doppler anemometer was used as the measurement system for droplet size and velocity. In case of single spray, injection pressure was varied from 0.2MPa to 0.7MPa. Mean axial velocity, mean radial velocity and droplet size were decreased as the distance below nozzle tip was increased. In case of twin spray, the spray characteristics were measured by varying the distance between two nozzles from 127mm to 155mm. In the overlap region, the boundary of the overlap region was determined by obtaining the distribution of mean axial and radial velocity. Droplet size was increased as the distance from nozzle tip was increased. It was found that the distribution of droplet size for twin spray in the overlap region was different to single spray.

DVB-S2 시스템을 위한 저복잡도 LDPC 복호 알고리즘

정지원,Jung Ji-Won 한국전자파학회 2005 한국전자파학회논문지 Vol.16 No.10

본 연구에서는 DTV, HDTV 서비스를 동시에 제공하는 차세대 위성 방송시스템의 표준안인 DVB-S2에서 채널 부호화 알고리즘으로 채택한 LDPC 부호의 복호 알고리즘에 대해 연구를 하였다. 샤논의 한계에 근접하기 위해서는 큰 블록 사이즈의 LDPC 부호어 길이와 많은 반복 횟수를 요구한다. 이는 많은 계산량을 요구하며, 그리고 이에 따른 전력 소비량(power consumption)을 야기시키므로 본 논문에서는 세 가지 형태의 low complexity LDPC 복호 알고리즘을 제시한다. 첫째로 큰 블록 사이즈와 많은 반복 회수는 많은 계산량과 power 소모량을 요구하므로 성능 손실 없이 반복 횟수를 줄일 수 있는 SUBSET 방법을 이용한 복호 알고리즘, 둘째로 early stop 알고리즘에 대해 연구하였고, 셋째로 비트 노드 계산과 체크 노드 계산시 일정한 신뢰도 값보다 크면 다음 반복시 계산을 하지 않는 early detection 알고리즘에 대해 연구하였다. In this paper, we first review LDPC codes in general and a belief propagation algorithm that works in logarithm domain. LDPC codes, which is chosen for second generation digital video broadcasting standard, are required a large number of computation due to large size of coded block and iteration. Therefore, we presented two kinds of low computational algorithm for LDPC codes. First, sequential decoding with partial group is proposed. It has same H/W complexity, and fewer number of iteration's are required at same performance in comparison with conventional decoder algerian. Secondly, early detection method for reducing the computational complexity is proposed. Using a confidence criterion, some bit nodes and check node edges are detected early on during decoding. Through the simulation, we knew that the iteration number are reduced by half using subset algorithm and computational complexity of early detected method is about $50\%$ offs in case of check node update, $99\%$ offs in case of check node update compared to conventional scheme.

소아기에 발현한 C형 Niemann Pick 병 1례

정지원,서고훈,오아름,진희경,배재성,김구환,유한욱,이범희,Jung, Jiwon,Seo, Go Hun,Oh, Arum,Jin, Hee Kyung,Bae, Jae-Sung,Kim, Gu-Hwan,Yoo, Han-Wook,Lee, Beom Hee 대한유전성대사질환학회 2018 대한유전성대사질환학회지 Vol.18 No.1

C형 Niemann-Pick 병은 NPC1 및 NPC2 유전자의 돌연변이로 인해 발생하며 상염색체 열성으로 유전된다. 신생아 간염 및 간비비대로 발현하며 안구의 수직운동 마비, 조화운동불능, 근육긴장이상, 경련 등의 신경학적 증상이 서서히 발현 하는 것을 특징으로 한다. 저자들은 복부 팽만 및 심한 비장비대로 입원한 3세 남아에서 간 조직 검사 및 유전자 검사, 섬유모세포의 Filipin 염색으로 확진 된 C형 Niemann-Pick 병 1례를 보고하는 바이다. Niemann Pick type C disease (NPC) is an inherited progressive neurodegenerative disorder, due to defects of intracellular lipid trafficking and storage. Hepatosplenomegaly may prevail, while progressive neurodegenerative symptoms such as cerebellar involvement, dystonia, vertical supranuclear ophthalmoplegia, cataplexy, and eventually seizures starting at juvenile or late infantile period may accompany after normal early development. Here we describe a 3-year-old Korean boy with NPC who presented with splenomegaly at age 3. Liver biopsy showed characteristic foamy cell stained by periodic acid-schiff, and molecular analysis for NPC1 identified the compound heterozygous mutations, novel mutation of c.1631G>A (p.Trp544Ter) and c.2662C>T (p. Pro888Ser) as a known mutation. Filipin was strongly stained with unesterified cellular cholesterol in the patient's skin fibroblasts. The patient has received migulstat since age 3 years and his long-term outcome is needed to be observed.