• Title/Summary/Keyword: cross sectional

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Evaluation on Adiabatic Property for Vehicular Sandwich Composite Structure (차체 구조용 샌드위치 복합소재 단열 특성 평가)

  • Lee Sang Jin;Oh Kyung Won;Jeong Jong Cheol;Kong Chang duk;Kim Jeong Seok;Cho Se Hyun
    • Composites Research
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    • v.19 no.1
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    • pp.9-14
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    • 2006
  • Experimental investigation on heat transfer ratio was firstly performed with three types of sandwich panels such as the Carbon/Epoxy Skin-Aluminum Honeycomb and Balsa Core Sandwich Panel of 37mm thickness, the Carbon/Epoxy Aluminum Skin-Honeycomb Core Sandwich Panel of 57mm thickness (including insulator) and the Carbon/Epoxy Skin-Aluminum Honeycomb Core Sandwich Panel of 37mm thickness based on the KS F 2278:2003(Insulation test method of windows). In additional to this investigation, experimental tests were also done for evaluation of heat transportation ratio with the Aluminum Skin- Aluminium Honeycomb Sandwich Panels of 27mm and 35mm thickness, and Aluminum Skin-Foaming Aluminum Sandwich Panel of 27mm thickness by the KS F2277:2002 (Insulation measuring method of construction component-Calibration heat box method or protective heat box method). In this study, it was found that the larger net heat transfer cross sectional area between the skin and the sandwich core is given, the higher heat transportation ratio occurs. It was also found that the hybrid type insulation had better insulation characteristics compared to the non-hybrid type insulation.

The Influence of Export Promotion Programs on SMEs' Export Performance: Focusing on Promising SMEs in Export (수출유망중소기업 지원프로그램이 수출성과에 미치는 영향에 관한 연구)

  • Jaekyung Ko;Chulhyung Park;Chang-Yong Han
    • Journal of Korea Society of Industrial Information Systems
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    • v.28 no.2
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    • pp.95-107
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    • 2023
  • The purpose of this study is to investigate the impact of export promotion programs (EPPs) on the export performance of small- and medium-sized enterprises (SMEs), with a specific focus on the influence of EPPs for promising SMEs in the export market. Using data on SMEs provided by the Industrial Bank of Korea (IBK), we conducted a fixed-effects model analysis from 2016 to 2019. Our study shows that EPPs have a positive and significant relationship with export intensity. Further analysis reveals that SMEs utilizing the financing support system provided by EPPs tend to improve their export growth and financial performance relative to their counterparts. While EPPs can assist SMEs with their internationalization efforts, their similarity and redundancy are recognized as potential limitations. This study complements the existing literature that has mainly focused on surveys and cross-sectional analysis by specifying the research subject to promising SMEs in export, and analyzing the effects of the export promotion program supported by IBK Industrial Bank. The results of this study are expected to provide implications for improving SMEs' export capabilities.

Relationship between the Thyroid Hormone and Viral Infections in Pregnancy (임신 중 바이러스성 감염요인과 갑상선 호르몬의 상관성)

  • Lim, Dong-Kyu;Park, Chang-Eun
    • Korean Journal of Clinical Laboratory Science
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    • v.54 no.1
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    • pp.28-37
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    • 2022
  • Pregnancy requires an important interpretation of thyroid function tests. The presence of anti-thyroid antibodies and viral infectious agents affect the health of both the fetus and the mother. Hence, a selective evaluation of thyroid function in pregnancy is required. This study is a retrospective cross-sectional survey to examine the correlation between thyroid hormones and viral infections during pregnancy. The results showed that the triiodothyronine (T3) decreased with increasing age, especially in the hepatitis C virus (HCV)-positive group (P<0.01). In addition, although negative for the human immunodeficiency virus (HIV), thyroxine (FT4) showed a significant increase in near-threshold or twin pregnant women (P<0.05). The thyroid stimulating hormone (TSH) was highly distributed at the age of 30, and there was no statistically significant correlation with other viral infection factors. In addition, as a result of dividing and analyzing the result of TSH by the quantiles, FT4 and T3 showed a positive correlation but showed a negative correlation with TSH (P<0.05). Therefore, the evaluation of prenatal thyroid screening during pregnancy and viral infection factors should reflect the time of pregnancy, exposure to infection, and the quantitative values. Adequate thyroid hormone and viral infections availability is important for an uncomplicated pregnancy and optimal fetal development.

A Review of the Korean Nursing Research Literature with MBTI Personality and Nursing Students (국내 간호학생 성격관련 연구 문헌고찰 : MBTI를 중심으로)

  • Hong, Eun-Young
    • Journal of the Korea Convergence Society
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    • v.13 no.1
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    • pp.425-436
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    • 2022
  • The purpose of this study was to explore the trends of research on MBTI (Myers-Briggs Type Indicator) and nursing students, and to suggest directions for nursing education geared to the needs of the future. The literature was searched using the National Assembly Library, Korean Studies Information Service System, DBPIA, Korean Medical database and National Discovery for Science Library to identify studies including MBTI personalty among nursing students. This study selected a total of 22 precedent studies regarding the investigation of MBTI personalty and nursing students. All studies were quantitative study and 63.6% of them were nonexperimental cross-sectional study. The most frequently selected category of variables was cognitive-perceptual related variables includes self-efficacy, self-eseem, academic self efficacy and etc. The most frequent MBTI personality type of nursing students was ISTJ (12.3%) and ESTJ (11.5%) was the second. Based on the findings of this study, longitudinal reasearch is recommanded on MBTI personality type and nursing specialty choice. Implications for teaching and learning strategies, and for using the results of MBTI in nursing students' career guidence are discussed.

The Impacts of Exploration and Exploitation Alliance on the Firm Performance: Focused on Global Supply Chain Management of 'Galaxy Note' (탐색제휴와 활용제휴가 기업의 성과에 미치는 영향: '갤럭시 노트'의 글로벌공급망을 중심으로)

  • Son, In-Sung;Kim, Si-Hyun
    • Korea Trade Review
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    • v.42 no.5
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    • pp.113-136
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    • 2017
  • New product preannouncement through global supply chain management and international strategic alliances is a critical issue for firm's survive and gaining the competitive advantage in the global smart-phone market. To identify the impact of exploration alliance and exploitation alliance on the short-term's Firm Performance, respectively, This study implemented the event study and the cross sectional regression analysis, focusing on the case of Galaxy Note series. Research results identified that new technologies by exploration alliance and the existing technologies through exploitation alliance have a positive effect on the short-term's performance of vendors related. Furthermore, information for the new products showed higher the excess earning rate than information related to the existing technologies. This implies the firms that provides new technologies have a stronger innovative ability than the companies serving the existing technologies, recognizing as a positive signal in the market. Finally, this study implicates that new technologies by exploration alliance enhances innovative abilities from new product preannouncement, and is a critical variable that can determines whether to survive in the market.

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Analysis of High-Temperature Corrosion of Heat Exchanger Tubes in Biomass Circulating Fluidized Bed Boiler (바이오매스 순환유동층 보일러의 열교환기 고온 부식 특성)

  • Yujin Choi;Dal-hee Bae;Doyeon Lee
    • Korean Chemical Engineering Research
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    • v.61 no.3
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    • pp.419-425
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    • 2023
  • This paper presents the research results of analyzing the high-temperature corrosion characteristics of three currently commercialized heat exchanger tube materials under actual operating conditions of a biomass power plant. In order to precisely analyze the high-temperature corrosion characteristics of these materials, a high-temperature corrosion evaluation device was installed in the power plant equipment, which allows for adjusting the surface temperature of the heat exchanger tubes. Experiments were conducted for approximately 300 hours under various temperature and operating conditions. In this study, the commercialized heat exchanger tube materials used were SA213T12, SA213T22, and SA213T91 alloys. In order to objectively analyze the high-temperature corrosion characteristics of each material, an international standard-based process to remove corrosion products was applied to obtain the weight change of the specimens, and the average thickness loss and corrosion rate were derived. Thus, the high-temperature corrosion results for each condition were quantitatively compared and analyzed. In addition, in order to increase the reliability of the high-temperature corrosion evaluation method introduced in this study, the surface and cross-sectional corrosion of the specimens were confirmed by using scanning electron microscopy and energy-dispersive X-ray analysis. Based on these analysis results, it was found that the corrosion resistance of the commercial heat exchanger materials increases as the content of chrome and nickel in the composition increases. Additionally, it was found that the corrosion phenomenon is rapidly accelerated as the surface temperature increases. Finally, the replacement period (lifetime) of the heat exchanger tubes under each condition could be inferred through this study.

Cross-sectional Study on Prevalence of Metabolic Syndrome in Stroke Patients (중풍환자의 대사증후군 유병률에 대한 단면조사연구)

  • Park, Seong-Uk;Lee, In-Whan;Jung, Woo-Sang;Moon, Sang-Kwan;Park, Jung-Mi;Ko, Chang-Nam;Cho, Ki-Ho;Kim, Young-Suk;Bae, Hyung-Sup
    • The Journal of the Society of Stroke on Korean Medicine
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    • v.9 no.1
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    • pp.25-32
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    • 2008
  • Objectives : Metabolic syndrome (MetS) is associated with increasing risk of cardiovascular morbidity and mortality but the risk of stroke associated with the MetS is less well established. The objective of this study was to evaluate the prevalence of MetS in stroke patients. Methods : We analyzed the data of 806 patients with acute ischemic stroke from Hanbang Stroke Registry supported by the Ministry of Science and Technology of Korea. Subjects' enrollment was done in the oriental medical hospitals of 4 universities located in the metropolitan region from April 2007 to August 2008. We analyzed all registered data and evaluated the prevalence of MetS and specific components of MetS. Results : The prevalence of MetS in stroke patients according to American Heart Association/National Heart Lung and Blood Institute (AHA/NHLBI) criteria was 59.6%. The prevalence according to the International Diabetes Federation (IDF) criteria was 41.6%. The prevalence of female patients was higher than that of male patients (71.8% vs 51% by AHA/NHLBI criteria; 61.7% vs 27.7% by IDF criteria). The prevalence of central obesity, low HDL cholesterol and hypertension was higher in female patients. There was no significant relationship between MetS and stroke subtype. Conclusions : This work gives us the basic data on the association between MetS and risk of stroke. There should be the prospective cohort studies to evaluate MetS and the risk of stroke.

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A Cross-sectional Study on the Distribution of Metabolic Syndrome according to Sasang Constitution in acute stroke patients (급성기 뇌경색 환자의 사상체질에 따른 대사증후군 분포 연구)

  • Sun, Jong-joo;Jung, Jae-han;Kim, Mi-young;Min, In-kyu;Choi, Won-woo;Hong, Jin-woo;Na, Byung-jo;Jung, Woo-sang;Moon, Sang-kwan;Cho, Ki-ho;Ko, Seong-gyu;Jun, Chan-yong;Han, Chang-ho
    • The Journal of the Society of Stroke on Korean Medicine
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    • v.8 no.1
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    • pp.22-27
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    • 2007
  • Objectives : This study was aimed to assess the distribution of metabolic syndrome according to Sasang constitution(SC) in acute stroke patients. Methods : We assessed the type of SC of acute stroke patients in the oriental medical hospitals of 3 universities located in metropolitan region from October 2005 to June 2007 by Ouestionnaire for the Sasang Constitution Classification II(QSCC II). Then, we investigated the general characteristics, the prevalence of each factor of the metabolic syndrome and the prevalence of the metabolic syndrome according to SC. Results : 338 subjects were included into the final analysis. 1. This study showed that the proportion of So-yang was highest of all constitutions(45.9%). 2. The prevalence of high TG, low HDL-chol, high BP, high FBS of Tae-um were higher than those of the other constitutions, but the differencecs were not statistically significant. The prevalence of high WC of Tae-um was significantly higher than other constitutions(p<0.001). 3. The prevalence of metabolic syndrome of Tae-um was significantly higher than other constitutions (p=0.002). Conclusion : There were significant differences in the prevalence of metabolic syndrome according to SC in acute stroke patients. For the further research, it seems to be necessary to construct fundamental databases for stroke by increasing the number of patients and by diagnosing SC more delicately.

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Cross-sectional study on the distribution of Sasang constitution in acute stroke patients (급성기 뇌경색 환자의 사상체질별 분포에 관한 단면적 연구)

  • Sun, Jong-joo;Jung, Jae-han;Jung, Woo-sang;Moon, Sang-kwan;Cho, Ki-ho;Ko, Seong-gyu;Chen, Chan-yong;Han, Chang-ho
    • The Journal of the Society of Stroke on Korean Medicine
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    • v.7 no.1
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    • pp.40-45
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    • 2006
  • Objectives : This study was aimed to assess the distribution of Sasang constitution(SC) in acute stroke patients. Methods : We assessed the type of SC of acute stroke patients in the oriental medical hospitals of 3 universities located in metropolitan region from October 2005 to October 2006 by Questionnaire for the Sasang Constitution Clssification II(QSCCII). We investigated general characteristics, stroke type, blood test results, alcohol drinking, smoking and dietary preferences according to SC. Results : 236 subjects were included into the final analysis. 1. This study showed that the proportion of So-yang was highest of all constitutions(45.3%). And the body weight, body mass index, the waist circumference(WC), the hip circumference(HC), and the WC/HC ratio recorded the significantly high result in Tae-eum. 2. In the TOAST classification, SVO was the major type occupying 81.7% in the total subjects. 3. In Tae-eum, total cholesterol, triglyceride and 2 hours postprandial plasma glucose level were the highest and fasting glucose was significantly highest of all constitutions. Conclusion : From this study, we could roughly seize the distribution of Sasang constitution in acute stroke patients. For the further research, it seems to be necessary to construct fundamental databases for stroke by increasing the number of patients and by analyzing delicate characteristics of each constitution type.

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Effect of Low-intensity Resistance Training with Blood Flow Restriction on Muscle Volume and Strength in Elderly Women (저강도의 저항성 운동 시 혈류제한 적용이 노인여성의 근 비대와 근력 향상에 미치는 영향)

  • Yeo, Hyo-Seong;Kim, Hyo-Jeong
    • 한국체육학회지인문사회과학편
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    • v.54 no.1
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    • pp.535-544
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    • 2015
  • This study was performed to determine the effect of low-intensity resistance training with blood flow restriction (BFR) on muscle volume and strength in elderly women. Sixteen elderly women (70.9±4.6 years) were divided into low (30% 1RM) and high (75% 1RM) intense resistance training groups. Tourniquet cuff (Zimmer, Germany) for BFR was applied only to the right leg during the training period. All subjects performed unilateral leg press, leg extension and leg curl (3 sets×12 repetitions) for 10 weeks (2d/wk). Blood pressure was increased from 110 to 240 mmHg during the training period at the most proximal region of exercised leg. Muscle volume and cross-sectional area (CSA) were measured by MRI and body composition was monitored by dual-energy X-ray absorptiometry (DEXA) and isokinetic muscular strength were analyzed in both legs. The quadriceps CSA (15.2%, p<.001) and muscle volume (13.8%, p<.001) were increased in high-intense trained leg with BFR and the increased rate was highest among groups. The quadriceps CSA (9.8%, p<.001) and muscle volume (6.9%, p<.001) were increased in low-intensity training group with BFR and their increased rates were higher than control groups. The strength by exercise training was significantly improved in all groups and tended to be higher in BFR groups. These results demonstrate low-intensity resistance training with blood flow restriction could be an effective way to improve muscle volume and strength in elderly women.