LDPC 부호의 복호를 위한 양자화 성능과 반복 횟수 통계

서영동(Young-Dong Seo),공민한(Min-Han Kong),송문규(Moon-Kyou Song) 대한전자공학회 2008 電子工學會論文誌-TC (Telecommunications) Vol.45 No.-

LDPC 복호기의 성능과 하드웨어 복잡도는 양자화 과정의 설계 변수인 클리핑 임계치(clipping threshold) cth와 양자화 비트 수 q, 그리고 복호과정의 최대 반복 횟수에 의존한다. 본 논문에서는 이상적인 Min-Sum 알고리즘과 양자화된 Min-Sum 알고리즘을 비교하기 위해서 시뮬레이션을 통해 클리핑 임계치 cth와 양자화 비트 수 q에 따른 LDPC 부호의 비트 오율 성능을 평가하였다. 시뮬레이션 결과 클리핑 임계치 cth = 2.5, 양자화 비트 수 q = 6일 경우에 이상적인 Min-Sum 알고리즘에 가장 근접한 비트 오율이 나타남을 확인할 수 있었다. 또한 반복 횟수의 통계적 분석을 통한 반복 횟수의 확률 밀도 함수를 이용하여 q와 반복 횟수에 따른 복호 복잡도를 계산하고, 부호어 에러율(word error rate; WER) 성능을 추정하였다. 이상의 결과는 LDPC 복호기 설계에서 부호의 성능과 복호 복잡도 사이의 절충을 위해 사용될 수 있다. The performance and hardware complexity of LDPC decoders depend on the design parameters of quantization, the clipping threshold cth and the number of quantization bits q, and also on the maximum number of decoding iterations. In this paper, the BER performances of LDPC codes are evaluated according to the clipping threshold cth and the number of quantization bits q through the simulation studies. By comparing the quantized Min-Sum algorithm with the ideal Min-Sum algorithm, it is shown that the quantized case with cth = 2.5 and q = 6 has the best performance, which approaches the idea case. The decoding complexities are calculated and the word error rates (WER) are estimated by using the pdf which is obtained through the statistical analyses on the iteration numbers. These results can be utilized to tradeoff between the decoding performance and the complexity in LDPC decoder design.

Soymilk를 이용한 요구르트 제조 및 저장기간 동안의 품질변화에 관한 연구

신상민 ( Sang Min Shin ),송광영 ( Kwang Young Song ),서건호 ( Kun Ho Seo ),윤여창 ( Yoh Chang Yoon ) 한국유가공기술과학회 2012 한국유가공기술과학회지 Vol.30 No.2

This study was performed for analyzing the general composition and the change in the quality of soymilk-derived yogurts manufactured by adding skim milk and whey powder to soymilk heat-treated at 95℃/5 min and 120℃/10 min, respectively. 1. During the storage of soymilk yogurt, the concentrations of total solids, protein, fat, and lactose slightly decreased, whereas viscosity, content of ash and NPN, and the number of lactic acid bacteria remained unchanged. 2. The pH and titratable acidity changed rapidly in all soymilk yogurts after 3 h of incubation. 3. We found 7.8×108 lactic acid bacteria in the control sample, 4.7×108 and 5.02×108 in soymilk yogurt with skim milk, respectively, and 5.9×108 and 5.5×108, respectively in soymilk yogurt with whey powder according to degree of heat treatment with 95℃/5 min and 120℃/10 min. 4. The viscosity of yogurt samples became lower as the heat treatment increased in temperature and in the length of time. 5. The value of sensory evaluation was relatively high in soymilk yogurt with the added skim milk, which was heat-treated 95℃/5 min; however, the value was significantly lower than that of the control sample. 6. Lactose, glucose, and galactose were detected in all samples because lactose is degraded into glucose and galactose within 3 h of inoculation.

연구보문 : 자연과학 ; 황산처리에 의한 불투수성 황근 종자의 발아촉진에 관한 연구

서상흠 ( Sang Heum Seo ),박민우 ( Min Woo Park ),장미하 ( Mi Ha Chang ),장일웅 ( Il Ung Jang ),심상인 ( Sang In Shim ),나영왕 ( Young Wang Na ),김수영 ( Soo Young Kim ),김석현 ( Seok Hyeon Kim ) 한국국제농업개발학회 2012 韓國國際農業開發學會誌 Vol.24 No.3

The reason of poor germination rate of hamabo mallow seed was speculated using TZ test to determine the viability of seed. Seeds showed high viability via TZ test were not germinated well. The quiescent seeds did not imbibed properly due to the hard seed coat and did not show further processes required for germination. Several well-known treatments for seed coat loosening and water uptake into seed were applied and compared for their efficiency. Stratification, hot water treatment, seed coat scarification, wet-cold treatment were revealed as less effective for improving germination although those treatments were common method for breaking dormant seed. Chemical scarification with sulfuric acid, however, effectively increased germinability and promptness index of hamabo mallow seeds. Optimal time for sulfuric acid treatment was 20 min. Seeds treated for 20 min showed improved germination percentage, germination speed, and promptness index of 80%, 13, and 1969 at 30 days after imbibition, respectively, in petri dish experiment. The values were greater than control seeds showed low values (12%, 1, and 183, respectively). The similar tendency was observed in the pot experiment that sulfuric acid treated seed were sown in artificially mixed soil (loamy soil:peatmoss:sand:compost = 5:2:2:1) and placed in greenhouse. Ultrastructure analysis of chemically scarified seed with sulfuric acid for 20 min by scanning electron microscopy did not show any noticeable changes in seed coat hardness and water uptake via hilum. But the only change after sulfuric acid treatment was removal of hilum cap that close the hilum and hider imbibition. Therefore, subsequent experiment was conducted to know the relationship between removal of hilum cap and facilitated imbibition by sulfuric acid treatment and whether the hilum cap removal directly influenced to the opening of micropyle. Water uptake velocity of seed treated for 20 min in concentrated sulfuric acid for was greater than control seed. This result implies that the crucial effect of sulfuric acid treatment is the removal of hilum cap that increase water uptake via micropyle in hamabo mallow.

Comparative evaluation of the algorithms for parametric mapping of the novel myocardial PET imaging agent ¹⁸ F-FPTP

Kim, Ji Who,Seo, Seongho,Kim, Hyeon Sik,Kim, Dong-Yeon,Lee, Ho-Young,Kang, Keon Wook,Lee, Dong Soo,Bom, Hee-Seung,Min, Jung-Joon,Lee, Jae Sung Springer Japan 2017 Annals of nuclear medicine Vol.31 No.6

<P><B>Objective</B></P><P>(<SUP>18</SUP>F-fluoropentyl)triphenylphosphonium salt (<SUP>18</SUP>F-FPTP) is a new promising myocardial PET imaging tracer. It shows high accumulation in cardiomyocytes and rapid clearance from liver. We performed compartmental analysis of <SUP>18</SUP>F-FPTP PET images in rat and evaluated two linear analyses: linear least-squares (LLS) and a basis function method (BFM) for generating parametric images. The minimum dynamic scan duration for kinetic analysis was also investigated and computer simulation undertaken.</P><P><B>Methods</B></P><P><SUP>18</SUP>F-FPTP dynamic PET (18 min) and CT images were acquired from rats with myocardial infarction (MI) (<I>n</I> = 12). Regions of interest (ROIs) were on the left ventricle, normal myocardium, and MI region. Two-compartment (<I>K</I><SUB>1</SUB> and <I>k</I><SUB>2</SUB>; 2C2P) and three-compartment (<I>K</I><SUB>1</SUB>–<I>k</I><SUB>3</SUB>; 3C3P) models with irreversible uptake were compared for goodness-of-fit. Partial volume and spillover correction terms (<I>V</I><SUB><I>a</I></SUB> and <I>α</I> = 1 − <I>V</I><SUB><I>a</I></SUB>) were also incorporated. LLS and BFM were applied to ROI- and voxel-based kinetic parameter estimations. Results were compared with the standard ROI-based nonlinear least-squares (NLS) results of the corresponding compartment model. A simulation explored statistical properties of the estimation methods.</P><P><B>Results</B></P><P>The 2C2P model was most suitable for describing <SUP>18</SUP>F-FPTP kinetics. Average <I>K</I><SUB>1</SUB>, <I>k</I><SUB>2</SUB>, and <I>V</I><SUB><I>a</I></SUB> values were, respectively, 6.8 (ml/min/g), 1.1 (min<SUP>−1</SUP>), and 0.44 in normal myocardium and 1.4 (ml/min/g), 1.1 (min<SUP>−1</SUP>), and 0.32, in MI tissue. Ten minutes of data was sufficient for the estimation. LLS and BFM estimations correlated well with NLS values for the ROI level (<I>K</I><SUB>1</SUB>: <I>y</I> = 1.06<I>x</I> + 0.13, <I>r</I><SUP><I>2</I></SUP> = 0.96 and <I>y</I> = 1.13<I>x</I> + 0.08, <I>r</I><SUP><I>2</I></SUP> = 0.97) and voxel level (<I>K</I><SUB>1</SUB>: <I>y</I> = 1.22<I>x</I> − 0.30, <I>r</I><SUP><I>2</I></SUP> = 0.90 and <I>y</I> = 1.26<I>x</I> + 0.00, <I>r</I><SUP><I>2</I></SUP> = 0.92). Regional distribution of kinetic parametric images (<I>αK</I><SUB>1</SUB>, <I>K</I><SUB>1</SUB>, <I>k</I><SUB>2</SUB>, <I>V</I><SUB>a</SUB>) was physiologically relevant. LLS and BFM showed more robust characteristics than NLS in the simulation.</P><P><B>Conclusions</B></P><P>Fast kinetics and highly specific uptake of <SUP>18</SUP>F-FPTP by myocardium enabled quantitative analysis with the 2C2P model using only the initial 10 min of data. LLS and BFM were feasible for estimating voxel-wise parameters. These two methods will be useful for quantitative evaluation of <SUP>18</SUP>F-FPTP distribution in myocardium and in further studies with different conditions, disease models, and species.</P><P><B>Electronic supplementary material</B></P><P>The online version of this article (doi:10.1007/s12149-017-1171-6) contains supplementary material, which is available to authorized users.</P>

Compressive Behavior of 7xxx Series Al Composites Reinforced with

Seo Young-Ik,Min Kyung-Ho,Lee Kyu-Hwan,Kim Young-Do 한국분말야금학회 2006 한국분말야금학회 학술대회논문집 Vol.2006 No.1

Mechanical properties of 7xxx series Al metal matrix composite (MMC) powders containing different amounts of ceramic were investigated. The ceramic contents of the starting powders were 5 wt.% or 10 wt.%. The powders were uniaxially cold compacted using a cylindrical die with a compacting pressure of 250 MPa and were sintered at in a dry atmosphere for 60 min. For the heat treatment, sintered parts were solution treated at and aged at . Compression tests were conducted to reveal the effect of particle content on the mechanical properties of the composites. Fractography was examined using a scanning electron microscope.

The Effect of Mobile Neurofeedback Training in Children with Attention Deficit Hyperactivity Disorder: A Randomized Controlled Trial

Seo Young Kwon,Gyujin Seo,Mirae Jang,Hanbyul Shin,Wooseok Choi,You Bin Lim,Min-Sup Shin,Bung-Nyun Kim 대한정신약물학회 2024 CLINICAL PSYCHOPHARMACOLOGY AND NEUROSCIENCE Vol.22 No.1

Objective: To examine the effect of mobile neurofeedback training on the clinical symptoms, attention abilities, and execution functions of children with attention deficit hyperactivity disorder (ADHD). Methods: The participants were 74 children with ADHD aged 8−15 years who visited the Department of Child and Adolescent Psychiatry at Seoul National University Children’s Hospital. The participants were randomly assigned to the mobile neurofeedback (n = 35) or control (sham; n = 39) group. Neurofeedback training was administered using a mobile app (equipped with a headset with a 2-channel electroencephalogram [EEG] sensor) for 30 min/day, 3 days/week, for 3 months. Children with ADHD were individually administered various neuropsychological tests, including the continuous performance test, Children’s Color Trails Test-1 and 2, and Stroop Color and Word Tests. The effects of mobile neurofeedback were evaluated at baseline and at 3 and 6 months after treatment initiation. Results: Following treatment, both mobile neurofeedback-only and sham-only groups showed significant improvements in attention and response inhibition. In the visual continuous performance test, omission errors decreased to the normal range in the mobile neurofeedback-only group after training, suggesting that mobile neurofeedback effectively reduced inattention in children with ADHD. In the advanced test of attention, auditory response times decreased in the mobile neurofeedback + medication group after training, but increased in the sham+medication group. Overall, there were no significant between-group differences in other performance outcomes. Conclusion: Mobile neurofeedback may have potential as an additional therapeutic option alongside medication for children with ADHD.

울릉도 소의 전염성 병원체 감염률 조사

서민구 ( Min Goo Seo ),도재철 ( Jae Cheul Do ),우인옥 ( In Ohk Ouh ),조민희 ( Min Hee Cho ),김중규 ( Joong Kew Kim ),김영환 ( Young Hoan Kim ),박노찬 ( No Chan Park ),곽동미 ( Dong Mi Kwak ) 한국가축위생학회 2011 韓國家畜衛生學會誌 Vol.34 No.4

Prevalence of infectious agents, including Brucella abortus (BA), Mycobacterium bovis (MB), bovine leukemia virus (BLV), M. avium subsp. paratuberculosis (MP), Neospora caninum (NC) and Toxoplasma gondii (TG), was investigated in all the cattle raised in Ulleung island during 2007∼ 2010. For BA, the prevalences in head and farm were 8.1% (44/545) and 5.5% (4/73) in 2007, all negative in 2008∼2009, and 0.5% (4/774) and 1.7% (1/58) in 2010, respectively. For MB, no sample was positive by PPD or ELISA in 2007∼2010. For BLV and MP, no sample was positive by ELISA in 2007∼2009. For NC, seroprevalences in head and farm were 0.2% (1/545) and 1.4% (1/73), respectively, in 2007 and all negative in 2008∼2009. For TG, seroprevalences in head and farm were 17.6% (97/552) and 54.8% (34/62) by ELISA in 2009. By regions, the seroprevalences of TG in Ulleung-eup, Seo-myeon and Buk-myeon were 26.0%, 9.8% and 16.7%, respectively, which had significant differences (P<0.0001). Tiger cattle were more resistant to TG infection than Hanwoo. The seroprevalence of TG in summer was higher than in autumn. The seroprevalence of TG in cows was higher than in oxen. The seroprevalence of TG in cattle was increased with age. In conclusion, this study indicates that the prevalences of six infectious diseases, except for TG which are widely spread, are relatively low in cattle reared in Ulleung island.

잘 알려진 창의적 과학자들의 과학적 문제 발견 패턴 분석

김영민 ( Young Min Kim ),서혜애 ( Hae Ae Seo ),박종석 ( Jong Seok Park ) 한국과학교육학회 2013 한국과학교육학회지 Vol.33 No.7

우리나라 과학교육에서는 과학 창의성의 계발을 강조하고 있다. 본 연구에서는 과학 창의성으로서 과학자들의 문제 발견에서 나타나는 패턴을 탐색하는데 목적을 두었다. 사례별 당시의 과학사적 상황, 문제발견의 과정 및 문제 해결에 대한 내용을 구체적으로 논의하였다. 연구 결과, 과학자 10명이 과학사적 사건을 발견할 때 특징적으로 나타내는 문제 발견의 패턴은 다음과 같은 5가지 패턴으로 발견되었다. 패턴 1의경우는 당시의 이론이나 설명이 불충분하거나 모순 또는 오류를 발견함에 의해 과학적 문제를 발견하는 것으로, 여기에는 라부아지에, 멘델, 왓슨의 문제 발견이 포함되었다. 패턴 2의 경우는 당대의 지식으로는 설명되지 않는 이상한 현상을 관찰함에 의해 문제를 발견하는 것으로, 여기에는 러더퍼드와 뢴트겐의 문제 발견이 포함되었다. 패턴 3의 경우는 비유 추론에 의해 문제를 발견하는 것으로, 카르노와 영의 문제 발견이 포함되었다. 패턴 4의 경우는 새롭게 발명된 관찰 또는 측정 기구를 사용하여 새로운 현상을 관찰함으로써 문제를 발견하는 것으로, 갈릴레이의 문제 발견이 포함되었다. 패턴 5의 경우는 연구 프로젝트 수행 중에 그 연구와 관련된 새로운 문제를 발견하는 것으로, 패러데이와 케플러의 문제 발견이 포함되었다. Nurturing students`` scientific creativity is considered an important element in science education in Korea. The study aims to explore patterns displayed by well-known scientists in their quest for problem finding. Each case of scientists`` course of problem solving is described in terms of historical background, a process of problem finding, and a process of problem solving. There are five patterns from ten scientists which are as follows: Pattern 1 is that scientists find problems from insufficiencies and/or errors from explanation of theories at the time and the related cases are A. Lavoisier, G. Mendel, and J. Watson. Pattern 2 shows that scientists find a problem because of strange phenomena unexplained by theories at the time, and here important case studies are E. Rutherford and W. Rontgen. Pattern 3 demonstrates that scientists find a problem from analogical reasoning between known theories and unknown science phenomena. The cases include S. Carnot and T. Young. Pattern 4 points to the fact that scientists find a problem while they utilize a newly invented experimental instrument. Here, G. Galilei is an important example. Pattern 5 establishes that scientists happen to find a problem while they conduct research projects. The works of M.Faraday and J. Kepler are prominent case studies related to this pattern.

급성 골수성 백혈병 환자에서 발생한 침습성 아스페르길루스중에 대한 수술적치료 1 예

배영환;어원식;어상민;김승만 김태영;박수영;서영경;정은주;안효정 인제대학교 2011 仁濟醫學 Vol.32 No.-

Invasive pulmonary aspergillosis is known to have a poor prognosis and major cause of morbidity and motality in patients with hematologic disease. Without adequate therapy, invasive pulmonary aspergillosis will almost always progress to fatal pneumonia. Early administration of antifungal agents in patient with invasive pulmonary aspergillosis is most important. And surgical resection of aspergillous-infected tissue may be useful in patients with lesions that are contiguous with great vessel and lesions causing hemoptysis. We reported a rare case of surgical resection as curative treatment for invasive pulmonary aspergillosis patient in 58-year-old man who had the history of acute myeloid leukemia.

적외선 체열촬영을 이용한 온천요법에 관한 임상적 연구

이정민 ( Jung Min Lee ),뱍인선 ( In Sun Park ),안택원 ( Taek Won Ahn ),홍서영 ( Seo Young Hong ) 한방재활의학과학회 2012 한방재활의학과학회지 Vol.22 No.1

Objectives :The purpose of this study was to investigate the influence of balneotherapy on the changes of DITI(digital infrared thermal imaging). Methods :This study was carried out on 27 patients. They went through balneotherapy with high pressure under water shower(15 min.) and whole body bathing in neutral or hot water between 32 to 40 ℃(15 min.). DITI was measured at before and after the treatment. And then the data was analyzed. Results :1. In cold hypersensitivity of hands group, temperature on PC8 rose and difference between LU4 and PC8 decreased(p<0.05)(Fig. 1, Table Ⅱ). 2. In cold hypersensitivity of feet group, temperature on LR3 rose and difference between ST32 and LR3 decreased(p<0.05)(Fig. 2, Table Ⅱ). 3. In shangrexiahanzheng(上熱下寒證) group, there were no significant changes on CV17, CV6 and difference between CV17 and CV6(Fig. 3, Table Ⅱ). Conclusions :These results demonstrated that balneotherapy has clinical effects on cold hypersensitivity of hands and feet. And further studies are required to apply the balneotherapy in order to cure various diseases in the future.