• 제목/요약/키워드: YoungChu

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잡음이 있고 흐릿한 영상의 블라인드 디컨벌루션을 위한 유전 프로그래밍 기법 (A Genetic Programming Approach to Blind Deconvolution of Noisy Blurred Images)

  • ;추연호;최영규
    • 정보처리학회논문지:소프트웨어 및 데이터공학
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    • 제3권1호
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    • pp.43-48
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    • 2014
  • 영상의 디컨벌루션은 보통 감시 시스템에서 모션 블러 (motion blur)나 초점이 맞지 않아 발생하는 블러 (out-of-focus blur) 문제를 줄이기 위해 전처리 과정에서 사용된다. 본 논문에서는 유전 프로그래밍 (Genetic Programming, GP)에 기반한 새로운 블라인드 영상 디컨벌루션 필터링 방법을 제안한다. GP 진화 과정을 통해 영상 복원을 위한 수학적 표현이 만들어지는데, 이것은 블러 영상의 특징들 사이의 관계를 최적으로 조합하여 원래 화소 값을 복원할 수 있는 추정자 함수가 된다. 이를 위해, 먼저 각 화소의 작은 이웃으로부터 특징 벡터를 만들고 추정자 함수를 학습시키는데, 이러한 GP 진화 과정을 통해 지정한 적합성 기준에 따라 유용한 정보들이 자동으로 조합된다. 개발된 함수는 훼손된 영상의 각 화소에 적용하여 원래의 화소 값을 복원하게 된다. 개발된 함수는 다양한 방법으로 훼손된 영상에 적용하여 실험하였는데, 실험 결과 제안된 방법이 기존 알고리즘에 비해 좋은 결과를 나타내는 것을 알 수 있었다.

Sun Ginseng Protects Endothelial Progenitor Cells From Senescence Associated Apoptosis

  • Im, Woo-Seok;Chung, Jin-Young;Bhan, Jae-Jun;Lim, Ji-Yeon;Lee, Soon-Tae;Chu, Kon;Kim, Man-Ho
    • Journal of Ginseng Research
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    • 제36권1호
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    • pp.78-85
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    • 2012
  • Endothelial progenitor cells (EPC) are a population of cells that circulate in the blood stream. They play a role in angiogenesis and, therefore, can be prognostic markers of vascular repair. Ginsenoside $Rg_3$ prevents endothelial cell apoptosis through the inhibition of the mitochondrial caspase pathway. It also affects estrogen activity, which reduces EPC senescence. Sun ginseng (SG), which is heat-processed ginseng, has a high content of ginsenosides. The purpose of this study was to investigate the protective effects of SG on senescence-associated apoptosis in EPCs. In order to isolate EPCs, mononuclear cells of human blood buffy coats were cultured and characterized by their uptake of acetylated low-density lipoprotein (acLDL) and their binding of Ulex europaeus agglutinin I (ulex-lectin). Flow cytometry with annexin-V staining was performed in order to assess early and late apoptosis. Senescence was determined by ${\beta}$-galactosidase (${\beta}$-gal) staining. Staining with 4'-6-Diamidino-2-phenylindole verified that most adherent cells (93${\pm}$2.7%) were acLDL-positive and ulex-lectin-positive. The percentage of ${\beta}$-gal-positive EPCs was decreased from 93.8${\pm}$2.0% to 62.5${\pm}$3.6% by SG treatment. A fluorescence-activated cell sorter (FACS) analysis showed that 4.9% of EPCs were late apoptotic in controls. Sun ginseng decreased the apoptotic cell population by 39% in the late stage of apoptosis from control baseline levels. In conclusion, these results show antisenescent and antiapoptotic effects of SG in human-derived EPCs, indicating that SG can enhance EPC-mediated repair mechanisms.

무선센서네트워크에서 부하 균등화를 위한 클러스터링 최적화 프로토콜 (Optimization Protocol using Load Balancing for Hierarchical Wireless Sensor Network)

  • 최해원;김상진;피수영;장주석
    • 디지털융복합연구
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    • 제11권10호
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    • pp.419-429
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    • 2013
  • 무선센서네트워크(WSN)는 다양한 환경에서 정보수집을 목적으로 하는 응용분야에 널리 사용된다. WSN을 구성하는 센서노드는 저 전력 배터리를 기반으로 동작하므로 이를 고려한 WSN 수명연장은 중요한 연구목표이다. 본 논문은 효율적인 WSN을 구성하기 위해 노드의 에너지 소비는 적으면서도 클러스터 부하 균등화를 이룰 수 있는 최적화된 클러스터링 프로토콜을 제시한다. 프로토콜의 핵심 아이디어는 센서노드가 저장할 수 있는 정보용량의 한계치를 이용해서 클러스터 멤버노드와 클러스터 밀집도가 균등분포(load balancing)되도록 하는 것이다. 또한 최적 클러스터 헤드 확률모델을 도입해서 WSN을 분할하는 클러스터가 최적화 되도록 한다. 이를 통해서 네트워크 부하의 적절한 분산과 에너지 소비 효율을 극대화하는 성능개선을 이끌어 낼 수 있다. 성능평가 결과 제안하는 프로토콜은 대표적인 계층형 프로토콜인 LEACH와 최근에 제안된 클러스터 기반 지역 멀티 홉 라우팅 프로토콜(CBLM)보다 더 수명이 연장되고 안정화 될 수 있었다.

급성 심장질환자 간호에 대한 웹기반 시뮬레이션과 고충실도 시뮬레이션 교육 효과 (Effects of Web-based Simulation and High-fidelity Simulation of Acute Heart Disease Patient Care)

  • 주민선;황윤영
    • 한국간호교육학회지
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    • 제23권1호
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    • pp.95-107
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    • 2017
  • Purpose: The aim of this study was to assess the efficacy of web-based simulation and high-fidelity simulation on acute heart disease patient care. Methods: The project used a comparative study design with two simulation-based training modalities. A total of 144 nursing students participated in this study: 76 students in a web-based simulation, and 68 students in a high-fidelity simulation. Participants rated their self-efficacy, problem-solving ability, interest in learning, level of stress, satisfaction with the simulation experience, and level of difficulty of the simulation. Results: The scores for self-efficacy, problem-solving ability, and interest in learning including interest in clinical training in the high-fidelity simulation group was higher than in the web-based simulation group. However, there were no significant differences in interest in learning, including interest in nursing knowledge, and in lab training, level of stress, satisfaction with the simulation experience, and level of difficulty of the simulation. Conclusion: A high-fidelity simulation of acute heart disease patient care might be beneficial to developing many more abilities for nursing students than would a web-based simulation. Also, since the web-based simulation improved interest in nursing knowledge, it could be a viable alternative to high-fidelity simulation. Further study is needed to verify the effects of varied levels of simulation-based care with more rigorous outcomes.

나노 산화층을 사용한 자기터널접합의 특성 (Characteristics of Magnetic Tunnel Junctions Incorporating Nano-Oxide Layers)

  • 추인창;전병선;송민성;이성래;김영근
    • 한국자기학회지
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    • 제16권2호
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    • pp.136-139
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    • 2006
  • 자기터널접합은 일반적으로 $250^{\circ}C$ 이상의 온도에서 터널자기저항비의 저하가 발생하는데 이는 반강자성체로 사용된 IrMn 중 Mn이 강자성체인 CoFe 및 터널배리어로의 내부확산에 기인한다. 자기터널접합의 열적 안정성을 향상시키기 위하여 나노산화층을 삽입하여 Mn의 확산을 제어하였다. CoNbZr 4/CoFe 10/IrMn 7.5/CoFe 3/터널배리어/CoFe 3/CoNbZr 2(nm)와 같은 자기터널접합을 기본구조로 하여 각각의 층에 나노산화층을 삽입하여 열적안정성 및 전자기적 특성을 비교 분석 하였다. 나노산화층의 삽입에 의해 터널자기저항비, 자기터널접합의 표면 평활도 및 열적안정성이 향상되었다.

폐질환 치료제의 효율적인 신약개발을 위한 생체표지자 및 대리결과 변수 (Biomarkers and Surrogate Endpoints for Development of New Drug on Pulmonary Disease)

  • 서정원;이병요;채정우;손추영;강원구;채한정;권광일
    • 약학회지
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    • 제54권2호
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    • pp.75-90
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    • 2010
  • Biomarkers are likely to be important in the study of various pulmonary diseases for many reasons. Research efforts in developing biomarkers and surrogate endpoints of lung diseases have resulted in the identification of new risk factors and novel drug targets, as well as the establishment of treatment guidelines. Government agencies, academic research institutions, diagnostic industries, and pharmaceutical companies all recognize the importance of biomarkers in new drug development and advancing therapies to improve public health. In drug development, biomarkers are used to evaluate early signals of efficacy and safety, to select dose, and to identify the target population. Identification of suitable end points not only would help investigators design appropriate clinical trials but would assist clinicians in caring for this patient population. Though the area of pulmonology has received much attention in the past decades, it still lags behind with regard to the development of biomarkers, particularly those of health effects and susceptibility. This review critically summarized several biomarker researches such as Evaluation of COPD Longitudinally to Identify Predictive Surrogate End-points (ECLIPSE) study with objectives of identifying the parameters that predict disease progression of COPD, as well as biomarkers that may serve as surrogate end-points.

A Case of Invasive Pulmonary Aspergillosis with Direct Invasion of the Mediastinum and the Left Atrium in an Immunocompetent Patient

  • Han, Kyu-Hyun;Kim, Jung-Hyun;Shin, Sun Young;Jeong, Hye Yun;Chu, Ji Min;Kim, Hak Su;Kim, Daejin;Shim, Minjung;Cho, Sang-Ho;Kim, Eun Kyung
    • Tuberculosis and Respiratory Diseases
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    • 제77권1호
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    • pp.28-33
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    • 2014
  • We report a case of invasive pulmonary aspergillosis invading the mediastinum and the left atrium. A 70-year-old woman was hospitalized for dyspnea. She had been well controlled for her diabetes mellitus and hypertension. The chest X-ray disclosed mediastinal widening, and the computed tomography scan of the chest showed that there was a large mediastinal mass and this lesion extended into the left atrium and right bronchus. The cardiac echocardiography showed that a huge mediastinal cystic mass compressed in the right atrium and a hyperechoic polypoid lesion in the left. The pathology from the bronchoscopic biopsy observed abundant fungal hyphae which was stained with periodic acid-Schiff and Gomori's methenamine silver. Despite the treatment with antifungal agents, she died from cardiac tamponade after three months. Invasive pulmonary aspergillosis, which involves the mediastinum and the heart, is very rare in immunocompetent patients.

일 지역 노인의 건강인식과 건강행태에 따른 우울 (Depression According to Health Perception and Health Practice Among the Aged in an Area)

  • 황윤영;주민선
    • 지역사회간호학회지
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    • 제18권4호
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    • pp.583-592
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    • 2007
  • Purpose: This study was performed to understand health perception, health practice, and depression of the elderly and to identify their depression level according to health perception and health practice. Method: The subjects were 463 elders who have lived in the Jeju Island and data were collected from June to August in 2005. Data were analyzed by SPSS 10.0. Result: The mean score of depression was 12.94 out of 30, and had a statistically significant correlation with educational level (F=2.943 p=.033), occupation (F=4.611. p=.010), and the number of chronic diseases (F=5.303. p=.001). When the cutoff of 18 points was applied based on Jung et al. (1997), the depression ratio was 12.4%, and when the cutoff parameter by Yesavage et al (1993) was applied, themoderate depression ratio was 74.8% and the severe depression ratio was 3.4%. In health recognition, consideration of usual health state had a significant correlation with depression (F=3.553 p=.007) but consideration of health state compared to the previous year wasn't. In health practice, sleeping was in a significant correlation with depression (F=3.574 p=.011), but smoking, alcohol drinking, exercise, and rest were not. Conclusion: Based on above results, we need further study on another sample group and the development, application, and verification of health management, education, and counseling programs for the elderly. Also, additional research should be made on significant factors of elderly depression.

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태양형(太陽形)에 대한 연구 (Study on TaeYang Type)

  • 김인진;강경화;이용태
    • 동의생리병리학회지
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    • 제21권4호
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    • pp.1030-1033
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    • 2007
  • Following conclusions about Taeyang meridian and Taeyang type were obtained through studies with reference to the books of ${\ll}$Donguibogam${\gg}$, ${\ll}$Hwangjaenaegyung${\gg}$, and ${\ll}$Special Lectures of Master Jisan on Medical cases${\gg}$ . Park noticed that there was difference in the development of 12 meridians among the individuals and tried to apply it in the diagnosis and the treatment of the disease, thereby creating the theory of the six meridian types. The literal basis is assumed to a phrase in ${\ll}$YoungChu GyungMaek${\gg}$ , ‘人經不同 絡脈異所別也’. Taeyang meridian runs through the back of the human body. The concept of TaeYang includes surface, starting point, diffusion of Yang Gi, and emission. Small intestine meridian of hand Taeyang manages the liquid and Bladder meridian of foot Taeyang manages the muscle. There is much flow of blood and less of Gi in Taeyang meridian which makes the connection to hair, flesh, liquid, muscle and vessel. Taeyang conceals and condenses objects because it belongs to Hansu according to division of Six atmospheric influences and to the winter. The articulation is stiff and urination and elimination are abnormal when disease occurs in this meridian. The pathology of Taeyang meridian would be the invasion of outer filthy Gi affecting the Bladder meridian of foot Taeyang which then again makes Kidney meridian of foot Soeum sick. The two meridians compose the outer part and the inner part of th body. The bladder itself becomes sick sometimes. The condition of less Gi in Taeyang meridian can easily result in the shortage of Gi, and much blood makes the person to have a lofty ideal or to have capricious behavior.

흰쥐의 급성 대장염에 대한 주파수에 따른 전침 효과 연구 (Frequency Dependent Electroacupuncture Modulates the Visceromotor Responses to Colonic Distension in TNBS-Induced Colonic Inflammatory Rats)

  • 최윤영;양승범;안성훈;손인철;김재효
    • 한국한의학연구원논문집
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    • 제17권3호
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    • pp.105-114
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    • 2011
  • Objectives : The transient inflammation has been demonstrated to alter visceral motor response (VMR) and acute mucosal inflammation may precede the manifestation of visceral hyperalgesia in animal models. The purpose of our study is to compare effects of the different frequencies applied electroacupuncture (EA) on acupoints in acute colitis induced by trinitrobenzenesulphonic acid (TNBS). Methods : In Male Sprague-Dawley rats, weighing 250~400g, a single colorectal administration of TNBS (5mg/kg) was made and electrode for electromyography (EMG) recording were stitched into the external oblique musculature. EA of either ST25 or ST36 were applied and stimulation parameter was modulated as follows: 2, 10, or 100 Hz with intensity of 2 mA and 1 ms pulse duration for 30 min. The balloon was inserted intra-anally and VMR to colorectal distension (CRD) was quantified with an EMG recording system. Results : The VMR increased significantly 3 days after TNBS intra-rectal colonic injection in rats. Both 2 Hz and 10 Hz EA on ST36 suppressed VMR to CRD in the acute colitis model but not 100 Hz. Only 10 Hz EA on ST25 suppressed VMR to CRD in the acute colitis. Conclusions : These data show that 10 Hz EA potently inhibits hypersensitivity of colorectum after TNBS induced colitis.