• Title/Summary/Keyword: $I_2$-convergence

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Forced Convection Heat Transfer for Two Circular Tube Arrays with Annular Fins (환형휜이 부착된 두 개의 원형관 배열에 대한 강제대류 열전달)

  • Kim, Seung-iI;Park, Sang-Hee
    • Journal of the Korean Society of Industry Convergence
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    • v.23 no.6_2
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    • pp.1093-1101
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    • 2020
  • This study was carried out numerically to investigate the air flow and thermal performance around single and parallel fin-tube heat exchangers and the cooling performance of the fluid inside the heat exchangers. In this study, the air velocity(1~7m/s), the pitch of fin(4, 6.1, 8, 11.3, 18.3, 44mm) and the diameter of fin(31, 33, 35, 37, 39mm) were varied. The flow rate of the water at the fin-tube heat exchanger inlet is 89cc/min and the water temperature is 353K. The air temperature at the upstream region of the heat exchanger is 300K. flow rate of the water at the fin-tube heat exchanger inlet is 80cc/min and the water temperature is 353K. It was found that the air pressure drop around single and parallel fin-tube heat exchangers was highly dependent on the air velocity and the fin pitch, but was independent of the fin diameter. Also, it was shown that pressure drop increased more the parallel arrangements than in single heat exchanger. The temperature difference of water at the inlet and outlet of the heat exchanger depended on the air velocity, the fin pitch and the fin diameter, and it was found that the parallel arrangement method further reduced the temperature of water. It was shown that the Nusselt number increased as the Reynolds number and the fin pitch increased, and decreased as the fin diameter increased.

Atmospheric Pressure Plasma Etching Technology for Forming Circular Holes in Perovskite Semiconductor Materials (페로브스카이트 반도체 물질에 원형 패턴을 형성하기 위한 상압플라즈마 식각 기술)

  • Kim, Moojin
    • Journal of Convergence for Information Technology
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    • v.11 no.2
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    • pp.10-15
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    • 2021
  • In this paper, we formed perovskite (CH3NH3PbI3) thin films on glass with wet coating methods, and used various analytical techniques to discuss film thickness, surface roughness, crystallinity, composition, and optical property. The coated semiconductor material has no defects and is uniform, the surface roughness value is very small, and a high absorption rate has been observed in the visible light area. Next, in order to implement the hole shape in the organic-inorganic layer, Samples in the order of a metal mask with holes at regular intervals, a glass coated with a perovskite material, and a magnet were etched with atmospheric pressure plasma equipment. The shape of the hole formed in the perovskite material was analyzed by changing the time. It can be seen that more etching is performed as the time increases. The sample with the longest processing time was examined in more detail, and it was classified into 7 regions by the difference according to the location of the plasma.

Reliability and Validity of the Korean version of autonomy preference index among patients with chronic disease (만성질환자 대상 한국어판 자율성 선호도 도구(K-Autonomy Preference Index)의 신뢰도 및 타당도 검증)

  • Lee, Jihae;An, Bomi
    • Journal of the Korea Convergence Society
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    • v.12 no.8
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    • pp.381-391
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    • 2021
  • The purpose of this study was to validate the Korean version of autonomy preference index (K-API) for chronic patients. Participants were 569 chronic patients. Construct validity and reliability of K-API were examined using exploratory and confirmatory factor analysis, and Cronbach's α test. Original API was translated to Korean, and we conducted contents validity test, and pilot test. The K-API consisted of 10 items divided into two domains: (i) Decision making preference (DMP); (ii) Information seeking preference (ISP). K-API explained 53.4% of autonomy preference; the two-factor structure showed an acceptance fit. Cronbach's α was. 77 for DMP, and. 75 for ISP. Validity and reliability of the K-API were established, and this study provides additional evidence for the usage of the API in Asian region.

Change in plasma cortisol and glucose levels of Oncorhynchus keta according to water temperature

  • Young Seok Seo;Hyo Bin Lee;Joo Hak Jeong;Seong Jun Mun;Han Kyu Lim
    • Fisheries and Aquatic Sciences
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    • v.26 no.2
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    • pp.117-132
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    • 2023
  • Chum salmon (Oncorhynchus keta) is a species of anadromous salmonid inhabiting coastal rivers in the North Pacific and the Arctic in the Bering and is the most widely distributed among Pacific salmon species. It is an important fish species in Korea as the salmon releasing project is being actively carried out. This study was conducted to investigate changes in the physiological activity of O. keta according to water temperature. Three experiments were conducted according to the water temperature and period, and the plasma concentrations of cortisol and glucose were analyzed from the blood samples of the experimental groups. Experiment I is a short-term water temperature experiment, in which water temperature stimulation was given for 4 hours at water temperatures of 12℃, 16℃ (control), 20℃, and 24℃, and a recovery period was given for 4 hours. Experiment II is an experiment in which water temperature stimulation was given for 24 hours, 48 hours, and 72 hours at a high temperature of 24℃, and a recovery period was given for 12 hours, respectively. Experiment III is a long-term water temperature experiment, in which the water temperature was 12℃, 16℃ (control), 20℃, and 24℃ for 8 weeks. As a result of the experiment, in Experiment I, there was no significant difference in the survival rate between the experimental groups, but the concentration of cortisol and glucose in the plasma according to the set water temperature showed a significant difference. In Experiment II, there was no significant trend according to the maintenance time of the high-temperature state, but as the temperature increased, the plasma cortisol and glucose levels significantly increased compared to the control group. In Experiment III, all of the experimental group C (24℃) died in the 1st week, and there was no significant difference in the plasma glucose at the 1st and 8th weeks among the remaining experimental groups.

A study on Classification of Book Trailers (북트레일러의 유형에 대한 연구)

  • Kim, Hyunhee
    • Design Convergence Study
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    • v.14 no.2
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    • pp.67-87
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    • 2015
  • With the development of cultural industries and technology, digital video marketing has grown immensely and 'Book Trailer' are now one of the main methods of promoting a title in publishing industry. The demands are growing, but the development lacks basic theoretical foundation and systematic structure. At this crucial moment, basic theoretical research on Book Trailer is necessary to establish a solid foundation for the medium to expand. In this study, I have focused on defining the basic concepts of Book Trailers and analyzing the classification of Book Trailers. In sorting the type of Book Trailers, content and formal appearance were used as standards. As a result, I was able to classify the content genre into message type, conflict type, character type using the elements of story. The formal appearance genre was classified into still photography type, motion typography type, interview type, story movie type and animation type.

Medicinal Plant Lemon Grass (Cymbopogon Citratus) Growth under Salinity and Sodicity

  • Ullah, Muhammad Arshad;Rasheed, Muhammad;Hyder, Syed Ishtiaq
    • The Korean Journal of Food & Health Convergence
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    • v.6 no.1
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    • pp.9-15
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    • 2020
  • Salinity with sodic condition disturbs germination, retards emergence, and slow down seedling development of Lemon Grass (Cymbopogon citratus).Lemongrass is a perennial grass plant widely distributed worldwide and most especially in tropical and subtropical countries. This research experiment was designed to evaluate the influences of (4 dSm-1+ 13.5 (mmol L-1)-1/2, 5 dSm-1+ 25 (mmol L-1)1/2, 5 dSm-1+ 30 (mmol L-1)1/2, 10 dSm-1+ 25 (mmol L-1)1/2 and 10 dSm-1+ 30 (mmol L-1)1/2) on biomass produce of lemon grass against salt tolerance. The uppermost biomass yield (45.53 gpot-1) was produced by 4 dSm-1+ 13.5 (mmol L-1)1/2 treatment. The increase in the intensity of salts reduced the growth of lemon grass. Lower biomass yield (79.33 gpot-1) was gained at 10 dSm-1+ 30 (mmol L-1)1/2. 5 dSm-1+ 25 (mmol L-1)1/2 treatment performed enhanced outcome i.e. the least reduction % over control (5.87). Salinity- sodicity showed serious effect on the growth reduction from 5.87% to33.60%. This reduction gap was affected by the negative effect of salinity and sodicity on Linseed growth. Salinity- sodicity showed severe impact on the growth reduction from 5.87% to33.60%. Based on the findings, lemon Grass (Cymbopogon citratus).was capable to grow up the maximum at 4 dSm-1+ 13.5 (mmol L-1)1/2 treatment.

Synthesis and biological evaluation of tricarbonyl technetium labeled 2-(4-chloro)phenyl-imidazo[1,2-a]pyridine analog (99mTc-CB257) as a TSPO-binding ligand

  • Choi, Ji Young;Jung, Jae Ho;Song, In Ho;Moon, Byung Seok;Lee, Byung Chul;Kim, Sang Eun
    • Journal of Radiopharmaceuticals and Molecular Probes
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    • v.4 no.2
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    • pp.73-79
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    • 2018
  • In our previous study, tricarbonyl $^{99m}Tc$-labeled TSPO-binding ligand, named $^{99m}Tc$-CB256, having positively charge (+1) was investigated but did not show promising results in in vivo environment despite of a nanomolar binding affinity for TSPO. Because the overall positively charge of $^{99m}Tc$-CB256 would likely interrupt its target protein uptake, we herein designed the neutral tricarbonyl-$^{99m}Tc$ labeled TSPO-binding ligand ($^{99m}Tc$-CB257, 1). $^{99m}Tc$-CB257 was prepared by the facile incorporation of the $[^{99m}Tc(CO)_3]^+$ into a N-(hydroxycarbonylmethyl)-2-picoly moiety in CB257. The radiochemical yield of $^{99m}Tc$-CB257 after HPLC purification was $54.1{\pm}2.4%$ (decay corrected, n = 3). The authentic Re-CB257 (2) was synthesized by using $(NEt_4)_2[Re(CO)_3Br_3]$ in 69.0% yield. The binding affinity of 2 for TSPO was measured in leukocyte and showed approximately 280 times higher than that observed for the positively charged (+1) ligand, Re-CB256 ($K_i=0.57{\pm}0.06nM$ versus $159.3{\pm}8.7nM$, respectively). Our results indicated that 1 can be considered potentially as a new SPECT radiotracer for TSPO-rich cancer and provides the foundation for further in vivo evaluation related with abnormal TSPO-overexpression environments.

Effects of Complex Probiotic Supplementation on Growth Performance, Nutrient Digestibility, Blood Metabolites, Noxious Gas and Fecal Microflora in Weaning Pigs (사료 내 복합생균제 첨가가 이유자돈의 사양성적, 영양소 소화율, 혈액성상, 분내 유해가스 및 분 중 미생물에 미치는 영향)

  • Kim, Dong-Woo;Choi, Yo-Han;Kim, Jo-Eun;Cho, Eun Seok;Jung, Hyun-Jung;Oh, Seung-Min;Kim, Jeong-Dae;Kim, Jin-Soo
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.21 no.5
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    • pp.266-273
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    • 2020
  • This study was undertaken to determine the effects of diet supplementation with complex probiotics (CPB), on growth performance, nutrient digestibility, blood metabolites, noxious gas, and fecal microflora in weaning pigs. On the basis of body weight, a total of 234 weaned pigs (Landrace×Yorkshire×Duroc, 6.14±0.78kg) were randomly allotted to 3 treatments and 6 replicates (13 pigs per pen). The experimental diets were fed in a meal form for 28 days (days 0-14, PhaseI, and days 15-28, PhaseII). The dietary treatment groups were as follows: T1 (basal diet), T2 (T1+0.13% CPB) and T3 (T1+0.25% CPB). The CPB supplement contained Bacillus subtilis 1.0×106 CFU/g, Enterococcus faecium 1.0×106 CFU/g, Saccharomyces cerevisiae 1.0×106 CFU/g, Bacillus licheniformis 3.0×108 CFU/g, and Bacillus polyfermenticus 3.0×108 CFU/g. Pigs fed the T3 diet showed an increase (p<0.05) in the overall average daily gain and average daily feed intake, increased (p<0.05) crude protein digestibility in PhaseI, and greater (p<0.05) dry matter and gross energy digestibility in PhaseII. Supplementation of CPB had no effect on the blood profile. Furthermore, pigs fed the T3 diet had lower (p<0.05) NH3 emission and overall count of fecal Clostridium spp. In conclusion, we believe that CPB supplementation has a beneficial effect on growth performance, nutrient digestibility, noxious gas, and fecal microflora in weaning pigs.

A Study on the Analysis of Electromagnetic Characteristics and Design of a Cylindrical Photonic Crystal Waveguide with a Low-Index Core (중심-동공을 갖는 원통형태 광결정 도파로의 전자장 특성 분석 및 설계 연구)

  • Kim, Jeong I.
    • Journal of the Korea Convergence Society
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    • v.12 no.2
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    • pp.29-34
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    • 2021
  • In this paper, a cylindrical photonic crystal waveguide with a low-index core is first proposed. The core can be filled with air, liquid, or arbitrary dielectric materials. Exact analyses for the electromagnetic field characteristics of guided modes, by using appropriate Bessel functions and applying the boundary conditions, are performed to find out the guiding characteristics of the proposed waveguide. For verification and usage in design and manufacturing process, the computer-calculation of the waveguide transmission characteristics is also performed by applying the rigorous full-vectorial finite difference method. Providing variations of the effective area for the fundamental mode of the designed waveguide with different numbers of cladding layers, ranging from 2.6056 ㎛2 to 5.9673 ㎛2 over the operation wavelength, generally as the core refractive index n1 is higher, the mode area becomes smaller and the result leads to more optimistic effect for nonlinear device applications.

Design of an Alpine Skiing Game Using ActionScript 3.0

  • Bai-Tiantain, Bai-Tiantain;Park, Jong-Hoon;Kim, Chul-Won
    • Journal of information and communication convergence engineering
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    • v.10 no.2
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    • pp.168-174
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    • 2012
  • Flash is the most popular 2D animation and game development software, supporting vector and media technology at the core, which enables the development of small and pithy games. It is widely used in Web animation, courseware, TV commercials, game development, and other works of design. In this paper, we propose a control movement function and auxiliary functions for an alpine skiing game based on ActionScript 3.0. The control movement function is designed with moving phases (i.e., free fall, sliding, projectile, and landing). The auxiliary functions include drawing path, start/restart movement, and saving the highest score. In addition, for the visual design of our game, we designed animations in connection with a character and background. In order to facilitate testing the friction, users can input a chosen friction value. Without user input, the friction default is set at 0.97.