• Title/Summary/Keyword: Si(001)

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Study on the Spin Valve Giant Magnetoresistance With a New Mn-Ir-Pt Antife rromagnetic Material (Mn-Ir-Pt 새로운 반강자성체를 사용한 스핀밸브 거대자기저항에 관한 연구)

  • 서수정;윤성용;김장현;전동민;김윤식;이두현
    • Journal of the Korean Magnetics Society
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    • v.11 no.4
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    • pp.141-145
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    • 2001
  • The Mn$\_$80/Ir$\_$18.1/Pt$\_$1.9/ exchange bias layers (EBLs), which have a small amounts of Pt, exhibit a high value of H$\_$ex/. The Si/Ni-Fe/Mn$\_$80/Ir$\_$18.1/Pt$\_$1.9/ EBL shows the largest H$\_$ex/ of 187 Oe, which is equivalent to a exchange energy (J$\_$ex/) of 0.146 erg/cm$^2$. Mn$\_$80/Ir$\_$18.1/Pt$\_$1.9/ EBLS are estimated to have blocking temperature of about 250 $\^{C}$, which is higher than those of Mn-Ir EBLs and Mn-Ir-Pt EBLs with higher Pt contents. This result implies that a little addition of Pt element promotes thermal stability in the Mn-Ir-Pt EBLs. The chemical stability of Mn-Ir-Pt EBLs was characterized by potentiodynamic test, which was performed in 0.001 M NaCl solution. The current density of Mn-Ir-Pt films was gradually reduced with increasing Pt content. The present results indicate that the Mn-Ir-Pt with a small amount of Pt is suitable for an antiferromagnetic material for a reliable spin valve giant magnetoresistance device.

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Development of Nonlinear Spring Modeling Technique of Group Suction Piles in Clay (점성토 지반에 근입된 그룹 석션파일에 대한 비선형 스프링 모델링 기법 개발)

  • Lee, Si-Hoon;Lee, Ju-Hyung;Tran, Xuan Nghiem;Kim, Sung-Ryul
    • Journal of the Korean Geosynthetics Society
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    • v.14 no.1
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    • pp.1-10
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    • 2015
  • Recently, several researches on the development of new economical anchor systems have been performed to support floating structures. This study focused on the group suction piles, which connect mid-sized suction piles instead of a single suction pile with large-diameter. The group suction pile shows the complex bearing behavior with translation and rotation, so it is difficult to apply conventional design methods. Therefore, the numerical modeling technique was developed to evaluate the horizontal bearing capacity of the group suction piles in clay. The technique models suction piles as beam elements and soil reaction as non-linear springs. To analyze the applicability of the modeling, the horizontal load-movement curves of the proposed modeling were compared with those of three-dimensional finite element analyses. The comparison showed that the modeling underestimates the capacity and overestimate the displacement corresponding to the maximum capacity. Therefore, the correction factors for the horizontal soil resistance was proposed to match the bearing capacity from the three-dimensional finite element analyses.

Adaptive Depth Fusion based on Reliability of Depth Cues for 2D-to-3D Video Conversion (2차원 동영상의 3차원 변환을 위한 깊이 단서의 신뢰성 기반 적응적 깊이 융합)

  • Han, Chan-Hee;Choi, Hae-Chul;Lee, Si-Woong
    • The Journal of the Korea Contents Association
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    • v.12 no.12
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    • pp.1-13
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    • 2012
  • 3D video is regarded as the next generation contents in numerous applications. The 2D-to-3D video conversion technologies are strongly required to resolve a lack of 3D videos during the period of transition to the full ripe 3D video era. In 2D-to-3D conversion methods, after the depth image of each scene in 2D video is estimated, stereoscopic video is synthesized using DIBR (Depth Image Based Rendering) technologies. This paper proposes a novel depth fusion algorithm that integrates multiple depth cues contained in 2D video to generate stereoscopic video. For the proper depth fusion, it is checked whether some cues are reliable or not in current scene. Based on the result of the reliability tests, current scene is classified into one of 4 scene types and scene-adaptive depth fusion is applied to combine those reliable depth cues to generate the final depth information. Simulation results show that each depth cue is reasonably utilized according to scene types and final depth is generated by cues which can effectively represent the current scene.

Dependence of Doping on Indium Content in InGaN/GaN Multiple Quantum Wells for Effective Water Splitting (다양한 In 조성을 가진 InGaN/GaN Multi Quantum Well의 효과적인 광전기화학적 물분해)

  • Bae, Hyojung;Bang, Seung Wan;Ju, Jin-Woo;Ha, Jun-Seok
    • Journal of the Microelectronics and Packaging Society
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    • v.25 no.3
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    • pp.1-5
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    • 2018
  • In this study, the effects of indium (In) doping in InGaN/GaN multi quantum well (MQW) on photoelectrochemical (PEC) properties were investigated. Each quantum well (QW) layer with controlled In content were grown on sapphire substrate. Before growth of MQW, GaN growth consisted of various stages in the following order: buffer GaN growth, undoped GaN growth, and Si-doped n-type GaN growth. Absorbance of InGaN/GaN MQW having different In composition was higher than that of the InGaN/GaN MQW having a constant In composition. It indicates that InGaN layer having different In composition absorbs light having a broad spectrum energy. These results are in agreement with those in photoluminescence (PL). After evaluation of PEC properties, it demonstrated that InGaN/GaN MQW having different In composition was improved InGaN/GaN MQW having constant In composition in PEC water splitting ability.

Nutritional status of patients treated with radiotherapy as determined by subjective global assessment

  • Koom, Woong Sub;Ahn, Seung Do;Song, Si Yeol;Lee, Chang Geol;Moon, Sung Ho;Chie, Eui Kyu;Jang, Hong Seok;Oh, Young-Taek;Lee, Ho Sun;Keum, Ki Chang
    • Radiation Oncology Journal
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    • v.30 no.3
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    • pp.132-139
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    • 2012
  • Purpose: The purpose of this prospective multi-institutional study was to evaluate the nutritional status of patients undergoing radiotherapy (RT) for treatment of head and neck, lung, or gastrointestinal cancer. Materials and Methods: A total of 1,000 patients were enrolled in this study at seven different hospitals in Seoul, Korea between October 2009 and May 2010. The nutritional status of patients after receiving 3 weeks of RT was evaluated using subjective global assessment (SGA). The nutritional status of each patient was rated as well nourished (A), moderately malnourished (B), or severely malnourished (C). Results: The mean age of patients in this study was $59.4{\pm}11.9$ years, and the male to female ratio was 7:3. According to the SGA results, 60.8%, 34.5%, and 4.7% of patients were classified as A, B, or C, respectively. The following criteria were significantly associated with malnutrition (SGA B or C; p < 0.001): loss of subcutaneous fat or muscle wasting (odds ratio [OR], 11.473); increased metabolic demand/stress (OR, 8.688); ankle, sacral edema, or ascites (OR, 3.234); and weight loss ${\geq}5%$ (OR, 2.299). Conclusion: SGA was applied successfully to assess the nutritional status of most patients. The prevalence of malnutrition in a radiation oncology department was 39.2%. The results of this study serve as a basis for implementation of nutrition intervention to patients being treated at radiation oncology departments.

Correlation between a Rupture of the Hypovascular Zone and Early Single Heel Raising after Achilles Tendon Repair (아킬레스건 봉합술 후 조기 단일 하지 거상과 아킬레스건 허혈성 구간 침범과의 상관관계)

  • Song, Si-Jung;Lee, Moses;Shin, Myung Jin;Suh, Jin Soo
    • Journal of Korean Foot and Ankle Society
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    • v.22 no.1
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    • pp.21-25
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    • 2018
  • Purpose: To analyze the correlation between a rupture of the hypovascular zone and early single heel raising after Achilles tendon repair. Materials and Methods: From January 2012 to August 2015, 68 patients, who underwent surgical treatment for a Achilles tendon rupture using Krackow method, were analyzed retrospectively. The patients were divided into two groups according to possibility of single heel raises within 3 months postoperatively. During the periodic outpatient observations, the visual analogue scale, Achilles tendon total rupture score (ATRS), and timing capable single heel raises were evaluated. In addition, the preoperative defect size and distance between the calcaneal osteotendinous junction and the rupture site were measured by ultrasound in all cases. Results: Twenty-three patients could perform a single heel raise within 3 months after surgery (early single heel raise group), and fortyfive patients could perform a single heel raise after 3 month postoperatively. The age, gender, body mass index, smoking, and operation delay were similar in the two groups. In addition, the defect size and distance between the calcaneal osteotendinous junction and rupture site as measured by preoperative ultrasound were similar (p=0.379 and p=0.631, respectively). On the other hand, when the rupture site was divided into the hypovascular zone (4~7 cm from calcaneal osteotendinous junction) and non-hypovascular zone, the hypovascular zone rupture rate was significantly lower in the early single heel raise group (60.9%, 14/23; 91.1%, 41/45; p=0.003). In logistic regression analysis, the odds of the hypovascular zone rupture group being capable of early single heel raise were 0.189 (p=0.017). The ATRS score at 3 months and 1 year after surgery were significantly higher in the early single heel raise group (p<0.001). Conclusion: Achilles tendon rupture at the hypovascular zone is a poor prognostic factor for early single heel raise and might affect the prognosis significantly after an Achilles tendon rupture operation.

Role of Aluminum Top-layer on Synthesis of Carbon Nanotubes using Laminated Catalyst(Al/Fe/Al) layer (적층구조 촉매층(Al/Fe/Al)을 이용한 탄소나노튜브의 합성에서 최상층 알루미늄 층의 역할)

  • Song, W.;Choi, W.C.;Jeon, C.;Ryu, D.H.;Lee, S.Y.;Shin, Y.S.;Park, C.Y.
    • Journal of the Korean Vacuum Society
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    • v.16 no.5
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    • pp.377-382
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    • 2007
  • In this study, we report the synthesis of the single-walled carbon nanotubes(SWCNTs) using laminated catalyst(Al/Fe/Al) layer deposited by sputter on Si(001). SWCNTs are grown by thermal chemical vapor deposition (TCVD) method. As the results of scanning electron microscopy(SEM), high resolution transmission electron microscopy(HR-TEM) and Raman spectroscopy, we confirmed the SWCNTs bundles with narrow diameter distribution of $1.14{\sim}1.32\;nm$ and average G&D ratio of 22.76. Compare to the sample having Fe/Al catalyst layer, it can be proposed that the top-aluminum incorporated with iron catalyst plays an important role in growing process of CNTs as a agglomeration barrier of the Fe catalyst. Thus, we suggest that a proper quantity of aluminium metal incorporated in Fe catalyst induce small and uniform iron catalysts causing SWCNTs with narrow diameter distribution.

Current Status of Systems Biology in Traditional Chinese medicine - in regards to influences to Korean Medicine (최근 중의학에서 시스템생물학의 발전 현황 - 한의학에 미치는 영향 및 시사점을 중심으로 -)

  • Lee, Seungeun;Lee, Sundong
    • Journal of Society of Preventive Korean Medicine
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    • v.21 no.2
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    • pp.1-13
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    • 2017
  • Objectives : This paper serves to explore current trends of systems biology in Traditional Chinese Medicine (TCM) and examine how it may influence the Traditional Korean medicine. Methods : Literature review method was collectively used to classify Introduction to systems biology, diagnosis and syndrome classification of systems biology in TCM perspective, physiotherapy including acupuncture, herbs and formula functions, TCM systems biology, and directions of academic development. Results : The term 'Systems biology' is coined as a combination of systems science and biology. It is a field of study that tries to understand living organism by establishing a theory based on an ideal model that analyzes and predicts the desired output with understanding of interrelationships and dynamics between variables. Systems biology has an integrated and multi-dimensional nature that observes the interaction among the elements constructing the network. The current state of systems biology in TCM is categorized into 4 parts: diagnosis and syndrome, physical therapy, herbs and formulas and academic development of TCM systems biology and its technology. Diagnosis and syndrome field is focusing on developing TCM into personalized medicine by clarifying Kidney yin deficiency patterns and metabolic differences among five patterns of diabetes and analyzing plasma metabolism and biomarkers of coronary heart disease patients. In the field of physical therapy such as acupuncture and moxibustion, researchers discovered the effect of stimulating acupoint ST40 on gene expression and the effects of acupuncture on treating functional dyspepsia and acute ischemic stroke. Herbs and formulas were analyzed with TCM network pharmacology. The therapeutic mechanisms of Si Wu Tang and its series formulas are explained by identifying potential active substances, targets and mechanism of action, including metabolic pathways of amino acid and fatty acid. For the academic development of TCM systems biology and its technology, it is necessary to integrate massive database, integrate pharmacokinetics and pharmacodynamics, as well as systems biology. It is also essential to establish a platform to maximize herbal treatment through accumulation of research data and diseases-specific, or drug-specific network combined with clinical experiences, and identify functions and roles of molecules in herbs and conduct animal-based studies within TCM frame. So far, few literature reviews exist for systems biology in traditional Korean medicine and they merely re-examine known efficacies of simple substances, herbs and formulas. For the future, it is necessary to identify specific mechanisms of working agents and targets to maximize the effects of traditional medicine modalities. Conclusions : Systems biology is widely accepted and studied in TCM and already advanced into a field known as 'TCM systems biology', which calls for the study of incorporating TCM and systems biology. It is time for traditional Korean medicine to acknowledge the importance of systems biology and present scientific basis of traditional medicine and establish the principles of diagnosis, prevention and treatment of diseases. By doing so, traditional Korean medicine would be innovated and further developed into a personalized medicine.

Pectinase-treated Panax ginseng protects against chronic intermittent heat stress-induced testicular damage by modulating hormonal and spermatogenesis-related molecular expression in rats

  • Kopalli, Spandana Rajendra;Cha, Kyu-Min;Lee, Sang-Ho;Ryu, Ji-Hoon;Hwang, Seock-Yeon;Jeong, Min-Sik;Sung, Jong-Hwan;Kim, Si-Kwan
    • Journal of Ginseng Research
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    • v.41 no.4
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    • pp.578-588
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    • 2017
  • Background: Elevated testicular temperature disrupts spermatogenesis and causes infertility. In the present study, the protective effect of enzymatically biotransformed Panax ginseng Meyer by pectinase (GINST) against chronic intermittent heat stress-induced testicular damage in rats was investigated. Methods: Male Sprague-Dawley rats (4 wk old, 60-70 g) were divided into four groups: normal control (NC), heat-stress control (HC), heat-stress plus GINST-100 mg/kg (HG100), and heat-stress plus GINST-200 mg/kg (HG200) treatment groups. Each dose of GINST (100 mg/kg and 200 mg/kg) was mixed separately with a regular pellet diet and was administered orally for 24 wk. For inducing heat stress, rats in the NC group were maintained at $25^{\circ}C$, whereas rats in the HC, HG100, and HG200 groups were exposed to $32{\pm}1^{\circ}C$ for 2 h daily for 6 mo. At week 25, the testes and serum from each animal were analyzed for various parameters. Results: Significant (p < 0.01) changes in the sperm kinematic values and blood chemistry panels were observed in the HC group. Furthermore, spermatogenesis-related molecules, sex hormone receptors, and selected antioxidant enzyme expression levels were also altered in the HC group compared to those in the NC group. GINST (HS100 and HS200) administration significantly (p < 0.05) restored these changes when compared with the HC group. For most of the parameters tested, the HG200 group exhibited potent effects compared with those exhibited by the HG100 group. Conclusion: GINST may be categorized as an important medicinal herb and a potential therapeutic for the treatment of male subfertility or infertility caused by hyperthermia.

Effects of BeHaS Program on Health Behavior, Physiologic Index and Self-Esteem of the Elderly Living Alone with Metabolic Syndrome Based on Community Based Participatory Research (지역사회기반 참여연구를 활용한 베하스(BeHaS) 프로그램이 대사증후군 독거노인의 건강행위, 생리적 지수 및 자아존중감에 미치는 효과)

  • Kim, Jong Im;Kim, Sun Ae;Park, Keumok;Kim, Jiyoung;Lee, Lina;Choi, Si Wan;Ku, Bon Jeong
    • Journal of Korean Academy of Nursing
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    • v.50 no.4
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    • pp.571-582
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    • 2020
  • Purpose: This study aimed to determine the effects of a 12-week metabolic syndrome BeHaS (Be Happy and Strong) program in elderly people with metabolic syndrome living alone, based on a community-based participatory research (CBPR). Methods: A nonequivalent control group pre-posttest design was used, and the participants were 43 elderly people living alone (experimental group 24, control group 19). The experimental group received a one-hour program per week and two individual health consultations during 12 weeks. The control group received two sessions about the metabolic syndrome and two individual health consultations. The effects of health behavior, blood pressure, blood sugar levels, abdominal circumference, triglycerides, and self-esteem were evaluated. The data were analyzed using the independent t-test and Mann-Whitney U test. Results: The health behavior with respect to the metabolic syndrome in the experimental group increased significantly (t = - 3.19, p = .002). Both diastolic blood pressure and abdominal circumference decreased in the experimental group (t = 2.00, p = .028 and t = 3.91, p < .001). No significant differences were observed between the groups in systolic blood pressure, fasting blood sugar levels, triglycerides, and self-esteem. Conclusion: The 12-week metabolic syndrome BeHaS program using community resources improves the health of elderly people with metabolic syndrome living alone. Based on these findings, further studies on the effectiveness of the metabolic syndrome BeHaS program and the experiences of those who participated in the CBPR are warranted.