반향 제거 회로 설계

권병우,이행우,유인호 호남대학교 정보통신연구소 1992 정보통신연구 Vol.1 No.-

본 논문은 U-트랜시버 내의 반향제거 회로를 설계하였다. 선로부호로 2B1Q 코드와 계수보정 회로에 대하여 sign 알고리즘을 사용하였다. 이 회로는 선형, 비선형 반향성분을 모두 제거할 수 있도록 설계하였으며, 약 65dB 이상의 반향제거 효과를 나타낸다. It is presented that this paper is described about a design of the echo cancelling circuit in the U-transceiver chip. The circuit can cancel the linear, non-linear echo signal, and record measure of echo cancelling about 65dB.

Comparative Evaluation of Nanofibrous Scaffolding for Bone Regeneration in Critical-Size Calvarial Defects

Woo, Kyung Mi,Chen, Victor J.,Jung, Hong-Moon,Kim, Tae-Il,Shin, Hong-In,Baek, Jeong-Hwa,Ryoo, Hyun-Mo,Ma, Peter X. Mary Ann Liebert 2009 Tissue engineering. Part A Vol.15 No.8

<P>In a previous study we found that nanofibrous poly(l-lactic acid) (PLLA) scaffolds mimicking collagen fibers in size were superior to solid-walled scaffolds in promoting osteoblast differentiation and bone formation in vitro. In this study we used an in vivo model to confirm the biological properties of nanofibrous PLLA scaffolds and to evaluate how effectively they support bone regeneration against solid-walled scaffolds. The scaffolds were implanted in critical-size defects made on rat calvarial bones. Compared with solid-walled scaffolds, nanofibrous scaffolds supported substantially more new bone tissue formation, which was confirmed by micro-computed tomography measurement and von Kossa staining. Goldner's trichrome staining showed abundant collagen deposition in nanofibrous scaffolds but not in the control solid-walled scaffolds. The cells in these scaffolds were immuno-stained strongly for Runx2 and bone sialoprotein (BSP). In contrast, solid-walled scaffolds implanted in the defects were stained weakly with trichrome, Runx2, and BSP. These in vivo results demonstrate that nanofibrous architecture enhances osteoblast differentiation and bone formation.</P>

400km/h급 전차선로 터널 하수강 구조안전성 분석

유향복(Hyang-Bok Ryoo),정상국(Sang-Gug Jeong),이인희(In-Hee Lee),송정관(Jung-Koan Song),우대현(Dai-Hyun Woo) 한국철도학회 2013 한국철도학회 학술발표대회논문집 Vol.2013 No.5

고속철도 건설과 차량개발에 대한 우리나라의 현재 수준은 차세대고속열차(HEMU-430X)를 개발하여 경부고속철도 구간에서 증속 시험운행중에 있으며, 400km/h급의 전차선로 시스템은 호남고속철도의 일부 구간을 시범적으로 선정하여 설치할 계획에 있다. 400km/h급의 전차선로는 상시 가선장력이 올라가 각종 지지물에 가해지는 상정하중이 증가하게 된다. 시범구간에는 터널이 존재하며 터널용 하수강을 사용하게 되며 터널 라이닝에 사전 매립된 C-챤넬에 고정하게 된다. 국내에서 처음 설계/시공되어지는 특성상 하수강의 구조적 안전성과 C-챤넬의 인발하중을 검토할 필요성이 있다. 본 연구에서는 토목공사에 반영된 C-챤넬의 규격, 공장시험결과, 시공상세도와 터널 하수강의 설계자료를 토대로 구조적 안전성을 분석하였다. In Korea, the newest technology concerning high-speed train construction and vehicle development is the next generation high-speed train (HEMU-430X). There is testing being done on the train in the Gyeongbu high-speed train section. The 400km/hour class track system is to be installed in the subinterval of Honam high-speed rail and will act as an example of how the train works. In the 400km/hour-class track, the weight that is on the supports increases because of growing real time stringing tension. In that section there is a tunnel which has vertical drop supports. It also has a c-channel fixing system, which had been previously installed in the tunnel. It is necessary to review the structural safety of the vertical drops and the pull out load of the c-channel. In this study we analyzed the structural safety by observing the quality of the c-channel based on engineering work, factory test results, and construction detail drawings. We also considered the design data of the vertical drop supports in the tunnel for our analyzation.

급성 호흡기 감염으로 입원한 소아 환자에서 Chlamydia pneumoniae의 임상 양상: Mycoplasma pneumoniae와의 비교

성재진 ( Jae Jin Sung ),김은진 ( Eun Jin Kim ),선용한 ( Yong Han Sun ),전인상 ( In Sang Jeon ),차한 ( Hann Tchah ),류일 ( Eell Ryoo ),손동우 ( Dong Woo Son ),조혜경 ( Hye Kyung Cho ),조혜정 ( Hye Jung Cho ),김나연 ( Na Yeon Kim 대한천식알레르기학회 2015 Allergy Asthma & Respiratory Disease Vol.3 No.5

Purpose: Chlamydia pneumoniae is a common intracellular bacterial pathogen and plays an important role in acute respiratory infections. The purpose of this study was to investigate clinical presentations of C. pneumoniae in children with acute respiratory infections. Methods: We examined the medical records of pediatric patients (age<18 years) admitted with acute respiratory infections of C. pneumoniae to Gachon University Gil Medical Center between March 1, 2011 and August 31, 2014. We compared the clinical features of C. pneumoniae infection with that of Mycoplasma pneumoniae infection. Results: We confirmed acute respiratory infections of C. pneumoniae in 110 patients out of 2,156 patients (5.1%) admitted with acute respiratory infections. The mean age was 37.2±30.1 months. More than half of them (54.5%) had coinfection. C. pneumoniae infection had mild and subacute courses. The mean duration of symptoms prior to admission was 8.5±13.8 days. There were remarkable seasonal variations and prevalence was higher in December and April (P=0.03 and P=0.02, respectively). Although rhinorrhea and pharyngeal injection were more common in C. pneumoniae infection (P<0.05), clinical signs and symptoms were similar between C. pneumoniae and M. pneumoniae. Extrapulmonary manifestations such as skin lesion, Gastrointestinal symptoms, hepatitis, and neurologic symptoms were common (41.0%) in C. pneumoniae infection and, had similar incidence in M. pneumoniae infection. Conclusion: C. pneumoniae is an important infectious agent of acute respiratory infections in children. Clinical pictures of C. pneumoniae are similar to M. pneumoniae, even in extrapulmonary manifestations. C. pneumoniae should be taken into consideration in differential diagnosis of acute respiratory infection in children. (Allergy Asthma Respir Dis 2015;3:346-351)

Clinical Features of Symptomatic Meckel's Diverticulum in Children: Comparison of Scintigraphic and Non-scintigraphic Diagnosis

Rho, Jung Hee,Kim, Jae Sook,Kim, Sang Yong,Kim, Soon Ki,Choi, Yoon Mi,Kim, Sung Min,Tchah, Hann,Jeon, In Sang,Son, Dong Woo,Ryoo, Eell,Cho, Kang Ho,Choi, Deok Young,Kim, Yoon Mi The Korean Society of Pediatric Gastroenterology 2013 Pediatric gastroenterology, hepatology & nutrition Vol.16 No.1

Purpose: Meckel's diverticulum (MD) has various clinical manifestations, and diagnosis or selectection of proper diagnostic tools is not easy. This study was conducted in order to assess the clinical differences of MD diagnosed by scintigraphic and non-scintigraphic methods and to find the proper diagnostic tools. Methods: We conducted a retrospective review ofthe clinical, surgical, radiologic, and pathologic findings of 34 children with symptomatic MD, who were admitted to Gachon University Gil Medical Center, Inha University Hospital, and The Catholic University of Korea, Incheon St. Mary's Hospital between January 2000 and December 2012. The patients were evaluated according to scintigraphic (12 cases; group 1) and non-scintigraphic (22 cases; group 2) diagnosis. Results: The male to female ratio was 7.5: 1. The most frequent chief complaint was lower gastrointestinal (GI) bleeding in group 1 and nonspecific abdominal pain in group 2, respectively. The most frequent pre-operative diagnosis was MD in both groups. Red blood cell (RBC) index was significantly lower in group 1. MD was located at 7 cm to 85 cm from the ileocecal valve. Four patients in group 1 had ectopic gastric tissues causing lower GI bleeding. The most frequent treatment modality was diverticulectomy in group 1 and ileal resection in group 2, respectively. Conclusion: To diagnose MD might be delayed unless proper diagnostic tools are considered. It is important to understand indications of scintigraphic and non-scintigraphic methods according to clinical and hematologic features of MD. Scintigraphy would be weighed in patients with anemia as well as GI symptoms.

염증장병 환아의 혈액학적 소견

권창규,남유니,선용한,류일,손동우,차한,전인상,Kwon, Chang-Gyu,Nam, Yoo-Nee,Sun, Yong-Han,Ryoo, Eell,Son, Dong-Woo,Tchah, Hann,Jeon, In-Sang 대한소아소화기영양학회 2009 Pediatric gastroenterology, hepatology & nutrition Vol.12 No.2

목 적: 최근 우리나라 소아에서 염증장병이 꾸준히 증가추세에 있으나 이들의 혈액학적 특징에 대해서는 알려진 바가 없다. 국내 염증장병 환아들의 장기간 관리에 도움이 되고자 혈액학적 소견을 분석하여 보았다. 방 법: 가천의대 길병원 소아청소년과에서 2002년 9월부터 2008년 9월 사이에 대장경과 생검으로 확진된 염증장병 환자 중 18세 이하인 25명의 염증장병 환아를 대상으로 하였다. 진단 당시의 혈색소, 적혈구용적률, 백혈구 수, 혈소판 수, 평균적혈구용적, 평균적혈구 혈색소량을 조사했다. 환아의 빈혈 빈도, 혈색소와 질병 이환기간과의 관계, 혈색소와 활동도지수와의 관계에 대하여 알아보았다. 결 과: 빈혈은 전체적으로 76% (19/25)에서 있었으며, 크론병 환아에서는 88% (14/16), 궤양결장염 환아에서는 56% (5/9)였다. 백혈구증가와 혈소판증가는 크론병 환아에서만 있었으며 빈도는 각각 56% (9/16), 25% (4/16)였다. 증상의 이환기간과 혈색소치는 크론병과 궤양결장염 모두에서 통계적인 유의성이 없었다. 활동도지수와 혈색소치도 크론병과 궤양결장염 모두에서 통계적인 유의성이 없었다. 결 론: 본 연구에서 염증장병 환아의 혈액학적 소견은 외국 문헌의 보고 내용과 큰 차이는 없었으나 빈혈의 빈도가 높았으며 질병의 이환기간 또는 활동도지수와 빈혈은 상관관계가 없었다. 이러한 사실은 염증장병환아를 장기간 관리하는 동안 빈혈에 대한 관리 역시 포함해야 하는 것을 시사하였다. 백혈구증가와 혈소판증가는 크론병에서만 관찰되어 궤양성장염과 감별진단하는데 도움이 될 수 있음을 제시하였다. Purpose: The aim of this study was to evaluate hematologic features in Korean children with inflammatory bowel disease (IBD) in order to determine appropriate management strategies. Methods: We retrospectively analyzed the complete blood count (CBC) profiles and assessed the incidence of anemia in 25 children with IBD (Crohn disease, 16; and ulcerative colitis, 9). The correlation between hemoglobin (Hb) and duration of illness and the activity index of IBD were also investigated. Results: The incidence of anemia was 76% in IBD, 88% in Crohn disease, and 56% in ulcerative colitis. Leukocytosis and thrombocytosis were only found in Crohn disease (56% and 25%, respectively). No statistically significant correlation was observed between Hb and duration of illness in Crohn disease and ulcerative colitis or between Hb and the activity index in Crohn disease and ulcerative colitis. Conclusion: The incidence of anemia found in this study was slightly higher than in previous reports. Additionally, there was no correlation between Hb and the duration of illness or the activity index. Therefore, even if the duration of illness is short, or the activity index is low, appropriate management of children with IBD should include careful evaluation for anemia.

원생대 하동회장암체 내 철-티탄 광체의 산상과 변형

정재성(Jae Sung Jung),김종선(Jong-Sun Kim),조형성(Hyeongseong Cho),송철우(Cheol-Woo Song),손문(Moon Son),류충렬(Chung-Ryul Ryoo),지세정(Seijeong Chi),김인수(In-Soo Kim) 한국암석학회 2010 암석학회지 Vol.19 No.1

한반도 남부 원생대 하동회장암체 내에는 주변 회장암의 암상과 무관하게 대략 남북방향으로 단속적으로 철-티탄 광체들이 출현한다. 이들 광체의 야외산상과 변형사를 밝히기 위하여 야외기재학적 특징과 주변 지질구조 분석 그리고 주요 암석과 광체 내 티탄철석에 대한 박편관찰과 전자현미분석을 실시하였다. 이번 연구의 대상 광체는 맥상과 층상 광체로 구분된다. 맥상 광체는 회장암체가 정치ㆍ고화된 이후에 관입하였음이 확실시되며, 층상 광체는 후기의 강력한 우수향 연성 전단작용에 의해 상대적으로 규모가 큰 맥상 광체가 압쇄암화 되고 전단엽리와 평행하게 전위된 결과로 해석된다. 철-티탄 광체는 청룡리, 월횡리, 종화리, 자양리와 백운리의 순서로 남에서 북으로 갈수록 후기 우수향 연성 전단변형을 많이 받았으며, 광체 내 티탄 철석의 함량은 감소하는 특징을 보인다. 광체 내 티탄철석은 야외산상과 후기 전단변형의 정도와 무관하게 유사한 화학조성을 가지며, TiO₂ 함량이 52~55 wt.% 내외로 자철석으로 용리되지 않은 순수한 티탄철석의 화학조성을 보여준다. 야외 지질구조 자료들을 분석하면, 하동회장암체는 마그마의 분화작용으로 만들어진 누적 엽리의 생성 이후에 북북동-남남서 습곡, 철-티탄 광체의 관입, 북북서~북북동 우수향 연성 전단작용, 북서~북북서 좌수향 아취성 전단작용, 그리고 북북동~북동 방향의 염기성 마그마의 관입의 순서로 변형된 것으로 판단된다. Nearly NS-trending Fe-Ti ore bodies intermittently occur in the Hadong anorthosites, south Korea, irrespective of the rock types of the anorthosites. In order to determine their occurrence mode and deformation history, we collected the features of occurrence and geological structures in the field, petrographic features using thin sections of the principal constituent rocks, and geochemical data of ilmenites in the ore body using electron probe microanalysis. Fe-Ti ore bodies examined in this study are divided into two types: dike- and lamina-types. It is steadily supported that the dike-type has intruded into the anorthositic rocks after their emplacement and solidification. And the laminar-type is probably a result of the mylonitization and transposition of the dike-type ore bodies parallel to the shear planes, due to later strong dextral ductile shearing. In the meantime, the Fe-Ti ore bodies have experienced the stronger dextral shearing in the more northern part of the study area, i.e. Cheongryong-ri, Wolhoeng-ri, Jonghwa-ri, and Jayangri and Baekun-ri in ascending order of its strength, together with the less content of TiO₂. All ilmenites of the ore bodies have very similar chemical composition, as pure ilmenite of 52~55 wt.% in TiO₂ content, irrespective of the occurrence mode and degree of later ductile shearing of the ore bodies. And they didn't experience to exsolve into magnetite. The structural data indicate that the Hadong anorthosites have deformed by NNE-trending folding, intrusion of the Fe-Ti ore bodies, NNW~NNEtrending dextral ductile shearing, NW~NNW-trending sinistral semi-brittle shearing, and intrusion of NNE~NE-trending mafic dykes in descending order of chronology after the formation of foliation of the anorthositic rocks. The foliation is interpreted as a result of the accumulation of crystals that settle out from the magma by the action of gravity.

Development of the Korean Version of the Gastrointestinal Quality of Life Index Questionnaire

( In Jun Yang ),( Heung-kwon Oh ),( Jeehye Lee ),( Jung Wook Suh ),( Hong-min Ahn ),( Hyeonjeong Park ),( Hyun Hee Sim ),( Yong Beom Cho ),( In Kyu Lee ),( Seungbum Ryoo ),( Dong-won Lee ),( Duck-woo 한국정맥경장영양학회 2022 한국정맥경장영양학회지 Vol.14 No.1

Purpose: To establish a standardized quality of life measurement that allows global cross-study comparisons, we translated the Gastrointestinal Quality of Life Index (GIQLI) into Korean and linguistically validated the Korean version of the GIQLI (K-GIQLI) in patients who underwent colorectal surgery. Materials and Methods: A cross-cultural adaptation of the original GIQLI was created based on the established guidelines. Based on participation in a cognitive interview, 20 patients with colorectal cancer were enrolled in the study. To ensure that the Korean version of the questionnaire was understood as intended, the time needed to complete the questionnaire was measured, and three additional items related to comprehension were added. Results: From May to July 2021, two translators, whose native language was Korean translated the GIQLI items into Korean, and a native English editor who had no knowledge of the original questionnaire translated the items back into English. In the cognitive interview, the median age of the patients was 61.8 (range: 44~82) years, and the median time required to complete the questionnaire was 6.5 (range: 5~10) min. For the language and cultural adaptation process, the participants’ comprehension of the questionnaire was measured on a scale of 1~5, with a mean score of 4 (range: 3~4). Conclusion: The K-GIQLI was developed and did not exhibit a significant difference from the original English version in terms of social, linguistic, and cultural differences between the Western world and Republic of Korea.

Performance Analysis of Iterative Detection Scheme for the D-STTD System

Yoon, Gil-Sang,Lee, Jeong-Hwan,Cho, In-Sik,Seo, Chang-Woo,Ryoo, Sang-Jin,You, Cheol-Woo,Hwang, In-Tae The Korea Institute of Information and Commucation 2009 Journal of information and communication convergen Vol.7 No.2

This paper combines various detection techniques and analyzes their performances in detecting the transmission information of the D-STTD scheme that uses, in parallel, the STTD scheme known as the Alamouti code. The D-STTD scheme adopts one of the STTD schemes for transmission to acquire diverse effects and uses another form of STTD for multiplexing effects. Due to the multiplexing effect that transmits different data, it is difficult to apply D-STTD to the conventional STTD combining technique. This paper combines the D-STTD system with linear algorithm, SIC algorithm and OSIC algorithm known as multiplexing detection scheme based on MMSE scheme. And we propose the detection scheme of the D-STTD using MAP algorithm and analyze the performance of each system. The simulation results showed that the detector using iterative algorithm has better performance than Linear MMSE Detector. Especially, we can show that the detector using MAP algorithm outperforms conventional detector.

Hepatitis associated with Mycoplasma pneumoniae infection in Korean children: a prospective study

Kim, Kyu Won,Sung, Jae Jin,Tchah, Hann,Ryoo, Eell,Cho, Hye Kyung,Sun, Yong Han,Cho, Kang Ho,Son, Dong Woo,Jeon, In Sang,Kim, Yun Mi The Korean Pediatric Society 2015 Clinical and Experimental Pediatrics (CEP) Vol.58 No.6

Purpose: Mycoplasma pneumoniae (MP) infection is a major cause of respiratory infection in school-aged children. Extrapulmonary manifestations of MP infection are common, but liver involvement has been rarely reported. The aim of this study was to determine the clinical characteristics of MP-associated hepatitis. Methods: This prospective study included 1,044 pediatric patients with MP infection diagnosed serologically with MP IgM at one medical center from January 2006 to December 2012. Eighty of these patients had elevated levels of serum aspartate aminotransferase (AST) and alanine aminotransferase (ALT), each greater than 50 IU/L, without any other specific liver disorder and were compared with the 964 children without liver disorders. Results: In total, 7.7% of patients with MP infection had a diagnosis of hepatitis, especially in fall and winter. The ratio of male to female patients was 1.7:1, and the mean age of the patients was 5 years and 5 months. The most common symptoms were cough, fever, and sputum. Anorexia was the most common gastrointestinal symptom, followed by nausea/vomiting, diarrhea, and abdominal pain. Mean levels of AST and ALT were 100.65 IU/L and 118.73 IU/L, respectively. Serum AST/ALT level was normalized within 7.5 days on average without complications. The mean duration of hospitalization (11.3 days) was longer for children with hepatitis than for those without hepatitis (P=0.034). Conclusion: MP-associated hepatitis is not uncommon and has a relatively good prognosis. Therefore, clinicians should be concerned about liver involvement in MP infection but avoid further unnecessary evaluation of hepatitis associated with MP.