• Title/Summary/Keyword: Enhanced

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An Experimental Study on Air-Side Performance of Fin-and-Tube Heat Exchangers Having Compound Enhanced Fins (복합 전열 촉진 핀이 적용된 핀-관 열교환기의 성능에 대한 실험적 연구)

  • Kim, Nae-Hyun
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.16 no.7
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    • pp.4364-4374
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    • 2015
  • In this study, heat transfer and friction characteristics of compound enhanced fin-and-tube heat exchangers were experimentally investigated. Louver-finned heat exchangers were also tested for comparison purpose. The effect of fin pitch on j and f factor was negligible. The j factor decreased as number of tube row increased. However, f factor was independent of number of tube row. Louver fin samples yielded higher j and f factors than compound enhanced fin samples. For one row, j and f factors of louver fin were 23% and 27% higher than those of compound enhanced fin. For two row, those were 11% and 8%, and for three row, those were 10% and 9%. However, heat transfer capacities at the same pressure drop of the compound enhanced fins were 6.4% for one row, 11.1% for two row and 13.6% for three row larger than those of louver fins, Existing louver fin correlation overpredicted the present j factors and underpredicted the present f factors.

Recognition of Concrete Surface Cracks Using Enhanced Max-Min Neural Networks (개선된 Max-Min 신경망을 이용한 콘크리트 균열 인식)

  • Kim, Kwang-Baek;Park, Hyun-Jung
    • Journal of the Korea Society of Computer and Information
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    • v.12 no.2 s.46
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    • pp.77-82
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    • 2007
  • In this paper, we proposed the image processing techniques for extracting the cracks in a concrete surface crack image and the enhanced Max-Min neural network for recognizing the directions of the extracted cracks. The image processing techniques used are the closing operation or morphological techniques, the Sobel masking for extracting for edges of the cracks, and the iterated binarization for acquiring the binarized image from the crack image. The cracks are extracted from the concrete surface image after applying two times of noise reduction to the binarized image. We proposed the method for automatically recognizing the directions of the cracks with the enhanced Max-Min neural network. Also, we propose an enhanced Max-Min neural network by auto-tuning of learning rate using delta-bar-delta algorithm. The experiments using real concrete crack images showed that the cracks in the concrete crack images were effectively extracted and the enhanced Max-Min neural network was effective in the recognition of direction of the extracted cracks.

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Analysis of Outcomes and Challenges on Problem Solving Ability Domain of Test for Enhanced Employ ability & Upgraded Proficiency by Meister and Specialized Vocational High School teachers and Industrial Workers (마이스터고 및 특성화고 교사와 산업체가 인식하는 직업기초능력평가 문제해결능력 영역의 성과와 과제 분석)

  • HAHM, Seung-Yeon
    • Journal of Fisheries and Marine Sciences Education
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    • v.27 no.4
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    • pp.948-962
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    • 2015
  • The purpose of this study was to inquiry of outcomes and challenges of Meister high school' and specialized vocational high school' teachers and industrial workers on problem solving ability domain of test for enhanced employ ability & upgraded proficiency, and what were outcomes and challenges of main factor by Meister high school and specialized vocational high school' teachers and industrial workers. Research subjects and region were teachers of Meister high schools and specialized vocational high schools in Gyeongsangnamdo and industrial workers in Gyeonggido. The sample(N=147) was drawn from Meister high school' teachers(N=90), specialized vocational high school' teachers(N=25) and industrial workers(N=32), and collected data were analyzed with SPSS using average, standard deviation, cross analysis, verification F. The results are as follows: The biggest outcomes of problem solving ability domain of test for enhanced employ ability & upgraded proficiency was change of educational direction for promoting core competency on specialized high school & Meister High School's students. The biggest positive ripple effects of the outcomes was also change of educational direction for promoting core competency on specialized high school & Meister High School's students. The biggest challenges of problem solving ability domain of test for enhanced employ ability & upgraded proficiency was importance of challenges was expansion of teacher training and lecture on the Test for Enhanced Employ ability & Upgraded Proficiency.

Effects of Meister High School and Specialized Vocational High School' Students on Career Maturity in Problem Solving Ability Domain of Test for Enhanced Employ ability & Upgraded Proficiency (직업기초능력평가 문제해결능력이 마이스터고 및 특성화고 학생의 진로성숙도에 미치는 영향)

  • Hahm, Seung-Yeon
    • Journal of Fisheries and Marine Sciences Education
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    • v.26 no.3
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    • pp.597-610
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    • 2014
  • The purpose of this study was to inquiry of influence of Meister high school and specialized vocational high school' students on career maturity in problem solving ability domain of test for enhanced employ ability & upgraded proficiency. Research subjects and region were sophomore students of each one of Meister high schools and specialized vocational high schools in Gwangju region. The sample(N=481) was drawn from 2 high schools and collected data were analyzed with SPSS using t-test, Pearson correlation and Levene's test. Items of problem solving ability domain of test for enhanced employ ability & upgraded proficiency were used test items developed in 2012. Career maturity test in Careernet site was used test items developed in 2001 which was made up 3 domains such as attitude, ability and action and 8 sub-regions such as planning, attitude on the vocation, independence, self-understanding, rational decision-making, explore of information, knowledge of hope vocation and career exploration and preparation of action, and constituted 64 items. The results were as follows. Findings of the analysis in specialized vocational high school students demonstrated the positive results of rational decision-making and explore of information in problem solving ability test for enhanced employ ability & upgraded proficiency. Comparing career maturity influence on Meister high school with specialized vocational high school students about problem solving ability domain of test for enhanced employ ability & upgraded proficiency, Meister high school students' score were more high grade than specialized vocational high school students grade.

Growth Responses at Different Growth Stage of Pinus densiflora Seedlings to Enhanced Uv-B Radiation (자외선-B 증가에 따른 소나무 유묘의 생장 단계별 생장 반응)

  • 김종진
    • Journal of Korea Foresty Energy
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    • v.19 no.1
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    • pp.1-6
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    • 2000
  • This study was carried out to investigate the growth responses of Pinus densiflora seedlings to enhanced UV-B environment for 16 weeks in the field condition. The seedlings were treated with one of three levels of UV-B dosages - ambient UV-B, ambient + 3.2, and ambient + 5.2 KJ m$^{-2}$day$^{-1}$ and the irradiation was performed at the stage before the germination, the fully expanded cotyledon, and the primary needles grown more than 0.8cm in length of the seedlings, respectively. Enhanced UV-B irradiation reduced the height and the root collar diameter growth, and dry mass production of the seedling, and T/R ratio was increased by the UV-B treatment. Difference in seedling growth was observed by difference in time of the UV-B treatment. Among the seedlings which were treated with ambient - 3.2 KJ m$^{-2}$day$^{-1}$, height and root collar diameter growth was relatively high in the seedling received the UV-B treatment at the stage before the germination. The lowest dry mass production was observed in the seedlings received the UV-B at stage of cotyledon both in two levels of enhanced UV-B treatment. Chlorophyll concentration was reduced by enhanced UV-B irradiation, and chlorophyll a/b ratio was increased by the UV-B treatment.

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An Experimental Study on Air-Side Performance of Fin-and-Tube Heat Exchangers Having Compound Enhanced Fins Under Wet Condition (복합 전열 촉진 핀이 적용된 핀-관 열교환기의 습표면 성능에 대한 실험적 연구)

  • Kim, Nae-Hyun
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.16 no.9
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    • pp.5778-5788
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    • 2015
  • In this study, wet surface heat transfer and friction characteristics of compound enhanced fin-and-tube heat exchangers were experimentally investigated. Louver-finned heat exchangers were also tested for comparison purpose. The effect of fin pitch on j and f factor was negligible. Both j and f factor decreased as number of tube row increased. Compound enhanced fin samples yielded higher j and f factors than louver fin samples. For one row, j and f factors of compound enhanced fin samples were 11% and 43% higher than those of louver fin samples. For two row, those were 8% and 50%, and for three row, those were 17% and 53%. Heat transfer capacities at the same pressure drop of the compound enhanced fin samples were 2.0% for one row, 3.1% for two row and 8.4% for three row larger than those of louver fin samples, Data were compared with predictions of existing louver fin correlations.

Diagnostic value of magnetic resonance imaging using superparamagnetic iron oxide for axillary node metastasis in patients with breast cancer: a meta-analysis

  • Lee, Ru Da;Park, Jung Gu;Ryu, Dong Won;Kim, Yoon Seok
    • Kosin Medical Journal
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    • v.33 no.3
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    • pp.297-306
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    • 2018
  • Objectives: Identification of axillary metastases in breast cancer is important for staging disease and planning treatment, but current techniques are associated with a number of adverse events. This report evaluates the diagnostic accuracy of superparamagnetic iron oxide (SPIO)-enhanced magnetic resonance imaging (MRI) techniques for identification of axillary metastases in breast cancer patients. Methods: We performed a meta-analysis of previous studies that compared SPIO enhanced MRI with histological diagnosis after surgery or biopsy. We searched PubMed, Ovid, Springer Link, and Cochrane library to identify studies reporting data for SPIO enhanced MRI for detection of axillary lymph node metastases in breast cancer until December 2013. The following keywords were used: "magnetic resonance imaging AND axilla" and "superparamagnetic iron oxide AND axilla". Eligible studies were those that compared SPIO enhanced MRI with histological diagnosis. Sensitivity and specificity were calculated for every study; summary receiver operating characteristic and subgroup analyses were done. Study quality and heterogeneity were also assessed. Results: There were 7 publications that met the criteria for inclusion in our meta-analysis. SROC curve analysis for per patient data showed an overall sensitivity of 0.83 (95% Confidence interval (CI): 0.75-0.89) and overall specificity of 0.97 (95% CI: 0.94-0.98). Overall weighted area under the curve was 0.9563. Conclusions: SPIO enhanced MRI showed a trend toward high diagnostic accuracy in detection of lymph node metastases for breast cancer. So, when the breast cancer patients has axillary metastases histologically, SPIO enhanced MRI may be effective diagnostic imaging modality for axillary metastases.

Enhancement of Cu Wire Bondability by Increasing the Surface Roughness of Capillary (표면 요철이 발달된 캐필러리 적용에 따른 Cu 와이어의 본딩 특성)

  • Lee, Jong-Hyun;Kim, Ju-Hyung;Kang, Hong-Jeon;Kim, Hak-Bum;Moon, Jung-Tak;Riu, Doh-Hyung
    • Korean Journal of Metals and Materials
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    • v.50 no.12
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    • pp.913-920
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    • 2012
  • In spite of some problems in processability and bondability, Au wires in the microelectronics industry are gradually being replaced by copper wires to reduce the cost of raw material. In this article, the effects of surface roughness enhanced capillaries on thermosonic Cu wire bonding were evaluated. The roughness-enhanced zirconia toughened alumina (ZTA) capillaries were fabricated via a thermal grooving technique. As a result, the shear bond strength of first bonds (ball bonds) bonded using the roughness-enhanced capillary was enhanced by 15% as compared with that of normal bonds due to more effective plastic deformation and flow of a Cu ball. In the pull-out test of second bonds (stitch bonds), processed at two limit conditions on combinations of process parameters, the bond strength of bonds formed using the roughness-enhanced capillary also resulted in values higher by 55.5% than that of normal bonds because of the increase in the bonding area, indicating the expansion of a processing window for Cu wire bonding. These results suggest that the adoption of roughness-enhanced capillaries is a promising approach for enhancing processability and bondability in Cu wire bonding.

Chemically enhanced steam cleaning for the control of ceramic membrane fouling caused by manganese and humic acid (망간과 휴믹산에 의한 세라믹 막 오염의 제어를 위한 약품 스팀세정의 적용)

  • An, Sun-A;Park, Cheol-Gyu;Lee, Jin-San;Kim, Han-Seung
    • Journal of Korean Society of Water and Wastewater
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    • v.35 no.6
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    • pp.425-436
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    • 2021
  • In this study, chemically enhanced steam cleaning(CESC) was applied as a novel and efficient method for the control of organic and inorganic fouling in ceramic membrane filtration. The constant filtration regression model and the resistance in series model(RISM) were used to investigate the membrane fouling mechanisms. For total filtration, the coefficient of determination(R2) with an approximate value of 1 was obtained in the intermediate blocking model which is considered as the dominant contamination mechanism. In addition, most of the coefficient values showed similar values and this means that the complex fouling was formed during the filtration period. In the RISM, R c/R f increased about 4.37 times in chemically enhanced steam cleaning compared to physical backwashing, which implies that the internal fouling resistance was converted to cake layer resistance, so that the membrane fouling hardly to be removed by physical backwashing could be efficiently removed by chemically enhanced steam cleaning. The results of flux recovery rate showed that high-temperature steam may loosen the structure of the membrane cake layer due to the increase in diffusivity and solubility of chemicals and finally enhance the cleaning effect. As a consequence, it is expected that chemically enhanced steam cleaning can drastically improve the efficiency of membrane filtration process when the characteristics of the foulant are identified.

Improved Oxidative Stability of Enhanced Pork Loins Using Red Perilla Extract

  • Lee, Da Gyeom;Lee, Juri;Jo, Kyung;Lee, Cheol Woo;Lee, Hyun Jung;Jo, Cheorun;Jung, Samooel
    • Food Science of Animal Resources
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    • v.37 no.6
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    • pp.898-905
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    • 2017
  • Enhanced meat is defined as fresh meat that has been minimally processed to improve quality and consistency. The present work investigated the quality of enhanced pork loins manufactured with the extract of red perilla leaves (ERP). ERP was prepared by the aqueous extraction of red perilla leaves followed by lyophilization. Enhanced pork loins were produced by injecting brine (15% v/w). The treatments consisted of a control (brine containing no ERP), ERP 0.2 (brine containing ERP at a concentration of 2 g/kg of pork loin), and ERP 0.4 (brine containing ERP at a concentration of 4 g/kg of pork loin). The enhanced pork loins were stored at $4^{\circ}C$ for 7 d, and its quality parameters were investigated. Addition of ERP decreased the $L^*$-value and increased the $a^*$- and $b^*$-values of enhanced pork loins compared to those of the control group at all storage intervals (p<0.05). A significantly lower pH than that of the control was found in ERP 0.4 after 7 d of storage. The malondialdehyde contents of the cooked pork loins were significantly lower in ERP 0.2 and ERP 0.4 than in those of the control after 4 and 7 d of storage (p<0.05). While ERP 0.4 received relatively low scores in taste, flavor, and overall acceptability of the cooked pork loins (p<0.05), no significant differences were found between the control and ERP 0.2. Enhanced pork loins can be produced using ERP to improve their oxidative stability.