• Title/Summary/Keyword: value circulation

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Numerical Simulation of Ozone using UAM-V on Summer Episode in the Costal Urban Area, Busan (UAM-V를 이용한 부산지역 고농도 오존사례 수치모의)

  • 김유근;오인보;황미경
    • Journal of Korean Society for Atmospheric Environment
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    • v.19 no.1
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    • pp.1-11
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    • 2003
  • Temporal and horizontal distributions of surface ozone concentrations covering the Busan metropolitan area were simulated by UAM -V (The Variable grid Urban Airshed Model) that was run with meteorological inputs taken from MM5 for ozone episode day (18 July 1999). UAM-V underestimated the daily maximum ozone con-centration about 14 ppb on average at all monitoring sites within Busan area comparing with observed value. but the correlation between observed and simulated values showed quite significant (R = 0.896, p< 0.01 on average). Higher concentrations of ozone occurred near the city center and industrial areas (western side of city) with high levels of anthropogenic source in the morning, and transport of ozone and its precursors by sea breeze developed in the afternoon contributed to elevated ozone levels in downwind rural areas. Particalarly in slightly downwind area of city center, the highest daily maximum ozone concentration ($\geq$120 ppb) was simulated by UAM-V at 1400 LST. Consequently, local environments including emission distributions and land -sea breeze circulation influenced ozone distributions in the Busan metropolitan area.

PIV Measurement of Circular Cylinder Wake Using Vortex Tracking Phase-Average Technique (와추적 위상평균 기법을 이용한 원주후류의 PIV측정)

  • Kim, Gyeong-Cheon;Yun, Sang-Yeol;Kim, Sang-Gi;Bu, Jeong-Suk
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.25 no.7
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    • pp.915-922
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    • 2001
  • A new phase-average technique using instantaneous velocity fields obtained by a PIV method has been developed. The technique tracks vorticity centers and estimates the value of circulation for a chosen domain. The locations of vortex-centers and the magnitudes of circulation are matched together then showing a sine wave feature due to the periodic vortex shedding from the circular cylinder. Ensemble averaged and phase averaged velocity fields are successfully measured for the circular cylinder wake where Reynolds number is 3900 based on free stream velocity and cylinder diameter. The convection velocities of the vortices center and the vortex shedding frequency were measured by a single hot-wire probe.

Characteristics of Gas-liquid Mass Transfer and Interfacial Area in a Bubble Column

  • Lim, Dae Ho;Yoo, Dong Jun;Kang, Yong
    • Korean Chemical Engineering Research
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    • v.53 no.3
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    • pp.315-320
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    • 2015
  • Characteristics of gas-liquid mass transfer and interfacial area were investigated in a bubble column of diameter and height of 0.102 m and 2.5 m, respectively. Effects of gas and liquid velocities on the volumetric gas-liquid mass transfer coefficient ($k_La$), interfacial area (a) and liquid side true mass transfer coefficient ($k_L$) were examined. The interfacial area and volumetric gas-liquid mass transfer coefficient were determined directly by adopting the simultaneous physical desorption of $O_2$ and chemical absorption of $CO_2$ in the column. The values of $k_La$ and a increased with increasing gas velocity but decreased with increasing liquid velocity in the bubble column which was operated in the churn turbulent flow regime. The value of $k_L$ increased with increasing gas velocity but did not change considerably with increasing liquid velocity. The liquid side mass transfer was found to be related closely to the liquid circulation as well as the effective contacting frequency between the bubbles and liquid phases.

A Case Study on Re:Design Collaboration for Sustainable Fashion Industry Revitalization (지속가능한 패션산업활성화를 위한 리디자인 협업 사례분석)

  • Kim, Minji;Lee, Kyujin
    • Journal of Fashion Business
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    • v.26 no.4
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    • pp.136-153
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    • 2022
  • The fashion industry is considered hazardous and a threatened to the environment. Due the negative perception, the industry should focus on sustainability as a social role. Therefore, several redesign fashion collaborations mainly focusing on renewing abandoned resources are already in place. The research method was based on previous studies, and 3 characteristics were derived: Redesign collaboration between fashion companies, Redesign collaboration between fashion & heterogeneous industries, and Redesign collaboration between the fashion industry & non-profit organizations. Those 3 characteristics were reviewed using 4 criteria. First, to establish and maximize the sustainable brand image and to be the best examples in environmental management, the organization endeavors to collaborate with various industries, institutions, and designers. Second is the expansion of the customer network through the spread of value consumption. Third is the creation of new values through a resource circulation structure. This means that the resource circulation structure system helps the partners to minimize on wastage. Fourth is the spread of de-boundary lines and the possibility of brand growth. Through collaboration with other industries, the boundaries of materials used in the fashion industry started to blur, thus expanding the continuous brand growth potential. The study derived the characteristics of redesign collaboration by systematically analyzing the cases. Further, the study looks forward to analyzing the characteristics of the products processed by redesign fashion collaborations in future research.

Optimization of Gas Mixing-circulation Plasma Process using Design of Experiments (실험계획법을 이용한 가스 혼합-순환식 플라즈마 공정의 최적화)

  • Kim, Dong-Seog;Park, Young-Seek
    • Journal of Environmental Science International
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    • v.23 no.3
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    • pp.359-368
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    • 2014
  • The aim of our research was to apply experimental design methodology in the optimization of N, N-Dimethyl-4-nitrosoaniline (RNO, which is indictor of OH radical formation) degradation using gas mixing-circulation plasma process. The reaction was mathematically described as a function of four independent variables [voltage ($X_1$), gas flow rate ($X_2$), liquid flow rate ($X_3$) and time ($X_4$)] being modeled by the use of the central composite design (CCD). RNO removal efficiency was evaluated using a second-order polynomial multiple regression model. Analysis of variance (ANOVA) showed a high coefficient of determination ($R^2$) value of 0.9111, thus ensuring a satisfactory adjustment of the second-order polynomial multiple regression model with the experimental data. The application of response surface methodology (RSM) yielded the following regression equation, which is an empirical relationship between the RNO removal efficiency and independent variables in a coded unit: RNO removal efficiency (%) = $77.71+10.04X_1+10.72X_2+1.78X_3+17.66X_4+5.91X_1X_2+3.64X_2X_3-8.72X_2X_4-7.80X{_1}^2-6.49X{_2}^2-5.67X{_4}^2$. Maximum RNO removal efficiency was predicted and experimentally validated. The optimum voltage, air flow rate, liquid flow rate and time were obtained for the highest desirability at 117.99 V, 4.88 L/min, 6.27 L/min and 24.65 min, respectively. Under optimal value of process parameters, high removal(> 97 %) was obtained for RNO.

Money Management Education Program for the Children -Higher Grade Elementary School Studuents- (아동소비자의 화폐관리교육 프로그램 -초등학교 고학년을 대상으로-)

  • 성영애;손상희;양세정;윤정혜;이희숙;최현자
    • Journal of Families and Better Life
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    • v.19 no.1
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    • pp.111-129
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    • 2001
  • This study was performed to develope a money management education program for elementary school students graded from 3 to 6 in order to enhance their money management skill. Based on the developmental stages of the children, this program covered five financial issues such as value of money, financial planning, allowance planning, saving and investment, and consuming and purchasing. Total 15 specific education programs were developed. The contents included in each program were value of money & economic circulation, types of money and the importance of money management, the issues related on choice and resource use, long-term and short-term planning, the relationship between occupation and earnings, career planning, budgeting, the reasons and types of saving, understanding of interest, investment methods, the functions of market and trade, intra family income distribution, consumptions, and consumer decision making process.

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Numerical Simulation of Advection and Diffusion using the Local Wind Model in Pusan Coastal Area, Korea (부산 연안역에서의 국지풍모델을 이용한 이류확산 수치모의)

  • 김유근;이화운;전병일
    • Journal of Korean Society for Atmospheric Environment
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    • v.12 no.1
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    • pp.29-41
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    • 1996
  • The two-stage numerical model was used to study the relation between three-dimensional local wind model, advection/diffusion model of random walk method and second moment method on Pusan coastal area. The first stage is three dimensional time-dependent local wind model which gives the wind field and vertical dirrusion coefficient. The second stage is advection/diffusion model which uses the results of the first stage as input data. First, wind fields on Pusan coastal area for none synoptic scale wind showed typical land and sea breeze circulation, and convergence zone occured at 1200LST in northern of domain, in succession, moved northward of domain. Emissions from Sinpyeong industrial district were trasnported toward the inland by sea breeze during daytime, and reached the end part of domain about 1800LST. During nighttime, emissions return to sea by land breeze and vertical diffusion also contributes to upward transport. In order to use this model for forecast of air pollution concentration on the Pusan coastal area, it is necessary that computed value must be compared with measured value and wind fields model must also be dealt in detail.

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A Clinical Study on SGOT,SGPT and LDH in the Patients of Open Heart Operation with Cardiopulmonary Bypass (개심술환자의 혈청효소치 변동에 관한 연구)

  • Park, Kang-Sik;Jee, Heng-Ok;Kim, Kun-Ho
    • Journal of Chest Surgery
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    • v.15 no.1
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    • pp.46-52
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    • 1982
  • Activities of serum glutamic pyruvic transaminase [SGPT], serum glutamic oxaloacetic transaminase [SGOT] and serum lactic dehydrogenase [LDH] were determined during and after surgery In a total of 18 patients with heart diseases Including 8 cases of congenital heart anomaly and 10 cases of acquired valvular diseases who undergone open heart surgery under cardiopulmonary bypass. The results obtained are as follows: 1]The average value of the activity of SGPT before the surgery was $27.94{\pm}12.24$ units. The value was increased following the operation and reached to the maximum value of $43.83{\pm}37.02$ units 2 days after the operation, which was slightly deviated from the normal range. The enzyme activity returned to the normal range of $32.82{\pm}23.61$ units 4 days after the operation. 2]The average value of the activity of SGOT before the surgery was observed to be $30.5{\pm}11.29$ units. The value increased during the operation and reached to the maximum value of $95.56{\pm}43.38$ units. 2 days after the operation, the enzyme activity was gradually decreased thereafter and returned to the normal range 6 days after the operation. 3]The average value of the activity of serum LDH before the surgery was found to be $258.0{\pm}88.96$ units. The value was increased during the operation and reached to the maximum value of $930.55{\pm} 258.23$ units 2 days after the operation. The enzyme activity was gradually decreased thereafter and returned to normal range 7 days after the operation. 4]It was observed that the longer the time required for the extracorporeal circulation in the open heart surgery became, the greater the changed in activity of SGOT, SGPT and serum LDH were found.

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Effect of 10 Weeks Smart Machine Circulation Exercise on Body Composition, Lung Function, Blood Lipids and Insulin Resistance in Obesity Middle-aged Women (10주간 스마트머신 순환운동이 비만 중년여성의 체조성, 폐기능, 혈중지질 및 인슐린 저항성에 미치는 영향)

  • Kim, Min-Chan;Ha, Soo-Min;Koh, Su-Han;Kim, Jong-Won;Kim, Do-Yeon
    • Journal of the Korean Applied Science and Technology
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    • v.38 no.4
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    • pp.951-962
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    • 2021
  • The purpose of this study was to analyze the effects of smart machine circulation exercise on body composition, lung function, blood lipid and insulin resistance in obesity middle-aged women among 40-60 years by dividing them into a smart machine circulation exercise group(n=8), and control group(n=6). The smart machine circulation exercise program included 55-minutes sessions thrice each week at the following intensities: The strength of aerobic exercise is applied to smart machines by linking the smart machine with the POLAR T31; the 1-4 week is 40-50%HRR, 5-8 week is 50-60%HRR, and 9-10 week is 60-70%HRR. The strength of the resistance exercise was tested using a smart machine based on the constant velocity motion, and then, using the 1-RM data value, applied 40% 1-RM for 1-4 weeks, 60% 1-RM for 5-8 weeks, and 80% 1-RM for 9-10 week. As a results, body composition indicated that weight, BMI, %BF, WHR had a significant interaction effect. Lung function indicated that FVC levels significantly changes in the exercise group and the between groups difference in changes at 10week was significant. Also, FVC and FEV1 significantly showed interaction effect. TC, TG and HDL-C levels significantly changes in smart machine circulation exercise group and the between-group difference in changes after 10 weeks was significant. TC, TG and HDL-C significantly showed interaction effect. Insulin resistance demonstrated that Insulin, Glucose and HOMA-IR levels significantly showed difference over 10 weeks between group. Therefore, the 10 weeks smart machine circulation exercise positively effects on the body composition, lung function, blood lipids, and insulin resistance in obesity middle-aged women and this smart machine circulation exercise can improve their obesity and prevent obesity.

Interrelationship Study about Pilotis space utilization in high-rise apartment complex and indicator values related with Space Syntax circulation -Focusing on Hwaseong Dongtan Newtown Area Apartment- (고층아파트단지 필로티 공간의 이용도와 공간구문론 동선관련 지표값과의 상관성 연구 -화성동탄신도시아파트를 중심으로-)

  • Song, Byung-Ha;Lee, Ki-Seok
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.16 no.8
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    • pp.5673-5682
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    • 2015
  • Purpose of this study is to examine and investigate the utilization of low-rise floor Pilotis space which is frequently selected as a major planning element in recent high-rise apartment complex and to identify the interrelationship between the placement of Pilotis space in the complex and space utilization frequency by comparing circulation related indicators of Connectivity, Control Value, Global Integration and Local Integration through Space Syntax axial analysis. Conclusions of this study are, first, Pilotis space is not used as a space to improve regional community consciousness because it is mostly used as a 'simple movement space'. Second, regarding space utilization frequency differences in Pilotis space in each apartment building, projecting entry access+pilotis addition type complex shows more significant utilization frequency than pilotis access type complex, and the vandalism phenomenon is observed more often. Third, Pilotis space utilization is related with Connectivity, Control Value, Global Integration and Local Integration which are circulation related indicators in Space Syntax, and Pilotis spaces with high indicator values over 2 tend to show higher utilization frequency and those with low indicator values over 2 tend to show low utilization frequency.