• Title/Summary/Keyword: Diffusion model

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Thin Layer Drying Model of Black Soybean (검은콩의 박층건조모델)

  • Lee, S.K.;Kim, H.;Kim, W.;Jeon, M.J.;Byun, J.S.;Han, J.W.
    • Proceedings of the Korean Society for Agricultural Machinery Conference
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    • 2017.04a
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    • pp.99-99
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    • 2017
  • 국내 콩의 소비량은 계속적으로 증가하고 있다. 재배 면적은 1995년 10,000ha에서 2013년 8,000ha까지 계속적으로 감소하였으며, 수입은 2009년 644.9백만 달러에서 2013년 883.3백만 달러까지 계속적인 증가 추세에 있다. 건조는 품질 손상을 최소화 및 수분을 제거하는 공정이다. 모든 곡물에는 건조 조건에 따라서 품질이 크게 변화하며, 건조 과정을 해석하여 해당 곡물의 적정 건조 조건을 구명하여 품질을 유지하는 위해서는 중요하다(Keum, 등 1977). 얇은 두께의 곡물층을 단층으로 하여 건조속도 및 건조공기의 조건을 나타내는 것을 박층(Thin layer)건조모델이라 한다. 박층건조모델을 계속적으로 쌓은 모델을 후층(Deep layer)모델이라 하며, 건조기 개발 및 건조조건 구명에 가장 기본이 된다(Basunia and Abe, 1998). 그러나 해외에서 만들어진 콩 박층건조 모델은 국내의 검은콩과 물성이 상이하여 건조조건이 다르게 설정 되어야 한다. 따라서, 본 연구목적은 건조온도 2수준, 상대습도 3수준에 대하여 검은 콩의 건조속도 측정하고, 곡물건조방정식으로 많이 이용되고 있는 4개의 건조방정식에 대하여 모델 적합성을 검정하여 검은콩 건조에 적합한 박층건조모델 결정하는데 있다. 공시재료는 2015년 강원도지역에서 생산된 검은콩을 실험에 사용하였으며, 초기 함수율은 14.7%,w.b.였다. 박층 건조공기 조성은 공기조화장치(MTH4100, SANYO, UK)를 사용하여 조성하였으며, 송풍기에 의해 공기충만실을 통과하여 건조 층을 통과하도록 구성하였다. 목표 평형함수율에 도달하면 실험을 종료하였다. 건조 층의 초기중량 및 경시적 변화는 전자저울(GF-4000, AND, Japan)을 이용하여 10분 간격 측정하여 저장하였다. 적정 박층건조모델을 결정하기 위하여 기존의 곡물건조방정식 중 널리 사용되고 있는 4개(Lewis, 1921; Page, 1949; Thompson, 1967; Moisture diffusion, 1975)의 건조모델을 이용하여 비교 검증하였다. 건조 초기 2시간 까지는 급격히 감소하다가 건조속도에 영향을 미치는 반건조시간(MR=0.5) 이후에는 완만하게 건조되는 것으로 나타났고 건조조건으로 건조온도 및 상대습도 모두의 영향이 미치는 것으로 나타났다. 4가지 건조 모델과 비교한 결과 Thompson 모델이 전체 건조 영역에서 비교적 잘 일치하였다.

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A Study on the Domestic Scale-up Policy Direction through the Analysis of Scale-up Support Policy for Global Startups (글로벌 창업기업 스케일업(Scale-up) 지원 정책 분석을 통한 국내 스케일업 정책 방향에 관한 연구)

  • Hong, Dae Ung;Jun, Byung Hoon
    • Asia-Pacific Journal of Business Venturing and Entrepreneurship
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    • v.14 no.6
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    • pp.11-27
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    • 2019
  • The second venture "boom" diffusion strategy can be confirmed to be focused only on financing investment and finance, including achieving 5 trillion won annually in new venture investments, creating 20 unicorns, activating M&As and creating dynamic recovery markets. Of course, existing studies show that the fund is a very important policy for corporate growth, but various policy support will be needed to effectively scale up. To overcome these limitations, the scale-up support policies already in operation are analyzed by introducing scale-up policies in advanced countries such as the U.S. and Britain. It also aims to analyze domestic scale-up policies to draw up implications for establishing more effective scale-up policies. Academically, we are very lacking in research on scale-up at home and abroad, and we propose suggestions through this comparative study of policy cases to contribute to the promotion of various studies related to the scalability aspects of future research topics related to scale-up.

The Study on Stakeholder' Concerns Regarding Consulting for Gifted Education Institutes (영재교육기관 컨설팅에 대한 영재교육 이해관계자의 관심도 연구)

  • Lee, Mi-Soon;Son, Sung Kuk
    • Journal of Gifted/Talented Education
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    • v.26 no.2
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    • pp.235-255
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    • 2016
  • This study examined whether there were differences in stakeholders' concerns regarding consulting in gifted education institutes. A total of 122 stakeholders in gifted and talented education responded to SoCQ(the Stage of Concerns Questionnaire, Hall & Hord, 2011). The SoCQ responses of these stakeholders to consulting for gifted education institutes were converted into relative intensities and SoCQ profiles, which were analyzed by the affiliated areas of institute, teaching years in gifted education, continuities of affairs in gifted education, and approaches to teacher training for gifted education with using t-test and one-way analysis of variance. Results indicated that stakeholders generally showed the highest concern for stage 1(information) and the lowest concerns for stage 4(consequence), which were the initial stage of change and innovation in consulting for gifted education institutes. In the meanwhile, skakeholders having training program for professionals showed the more concern for stage 6(refocusing), which was a kind of resistance for the present consulting for gifted education institutes. On the based on these results, this study suggested ways(or methods) for settlement and the diffusion of successful gifted education consulting.

Health and environmental risk assesment of air pollutants in Gyeongju and its vicinities(I) (경주 주변지역 대기오염물질의 보건.환경 위해성 평가(I))

  • Jung, Jong-Hyeon;Choi, Won-Joon;Leem, Heon-Ho;Park, Tong-So;Shon, Byung-Hyun
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.10 no.12
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    • pp.3740-3747
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    • 2009
  • To protect the citizens' health of Gyeongju and to secure basic data for the assessment of health and environmental risk, distribution characteristics of meteorological elements were investigated and numerical simulation of wind field using RAMS model was carried out. In addition, measurement and analysis of air pollutants, forecasting the behavior air pollutants using ISC-AEROMOD view, and health and environmental risk-influenced zones were defined through managing air polluting materials to prevent health damage and property damage. According to the survey results of air pollution in Gyeongju and surroundings, average annual concentration of air pollutants in Gyeongju was slightly lower than that in Pohang and Ulsan areas, but concentration of particulate matters and nitrogen dioxide at Gyeongju Station Square and Yonggang Crossing were sometimes higher than that in Pohang and Ulsan areas. Results of the modeling of moving and diffusion of air pollutants that affect citizens' health showed that parts of the 1st through 4th industrial complexes together with POSCO were included in particulate matters and sulfur dioxide influenced areas in Pohang Steel Complex area, and that Haedo-dong, Sangdae-dong, Jecheol-dong and Jangheung-dong in Pohangnam-gu represented locally worsened air quality due to a quantity of air pollutant emission from dense steel industries and large scale industrial facilities.

Anatomical Brain Connectivity Map of Korean Children (한국 아동 집단의 구조 뇌연결지도)

  • Um, Min-Hee;Park, Bum-Hee;Park, Hae-Jeong
    • Investigative Magnetic Resonance Imaging
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    • v.15 no.2
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    • pp.110-122
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    • 2011
  • Purpose : The purpose of this study is to establish the method generating human brain anatomical connectivity from Korean children and evaluating the network topological properties using small-world network analysis. Materials and Methods : Using diffusion tensor images (DTI) and parcellation maps of structural MRIs acquired from twelve healthy Korean children, we generated a brain structural connectivity matrix for individual. We applied one sample t-test to the connectivity maps to derive a representative anatomical connectivity for the group. By spatially normalizing the white matter bundles of participants into a template standard space, we obtained the anatomical brain network model. Network properties including clustering coefficient, characteristic path length, and global/local efficiency were also calculated. Results : We found that the structural connectivity of Korean children group preserves the small-world properties. The anatomical connectivity map obtained in this study showed that children group had higher intra-hemispheric connectivity than inter-hemispheric connectivity. We also observed that the neural connectivity of the group is high between brain stem and motorsensory areas. Conclusion : We suggested a method to examine the anatomical brain network of Korean children group. The proposed method can be used to evaluate the efficiency of anatomical brain networks in people with disease.

Efficiency Evaluation of Mobile Emission Reduction Countermeasures Using Data Envelopment Analysis Approach (자료포락분석(DEA) 기법을 활용한 도로이동오염원 저감대책의 효율성 분석)

  • Park, Kwan Hwee;Lee, Kyu Jin;Choi, Keechoo
    • Journal of Korean Society of Transportation
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    • v.32 no.2
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    • pp.93-105
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    • 2014
  • This study evaluated the relative efficiency of mobile emission reduction countermeasures through a Data Envelopment Analysis (DEA) approach and determined the priority of countermeasures based on the efficiency. Ten countermeasures currently applied for reducing greenhouse gases and air pollution materials were selected to make a scenario for evaluation. The reduction volumes of four air pollution materials(CO, HC, NOX, PM) and three greenhouse gases($CO_2$, $CH_4$, $N_2O$) for the year 2027, which is the last target year, were calculated by utilizing both a travel demand forecasting model and variable composite emission factors with respect to future travel patterns. To estimate the relative effectiveness of reduction countermeasures, this study performed a super-efficiency analysis among the Data Envelopment Analysis models. It was found that expanding the participation in self car-free day program was the most superior reduction measurement with 1.879 efficiency points, followed by expansion of exclusive bus lanes and promotion of CNG hybrid bus diffusion. The results of this study do not represent the absolute data for prioritizing reduction countermeasures for mobile greenhouse gases and air pollution materials. However, in terms of presenting the direction for establishing reduction countermeasures, this study may contribute to policy selection for mobile emission reduction measures and the establishment of systematic mid- and long-term reduction measures.

Study on of Process Parameters for Adsorption of Reactive Orange 16 Dye by Activated Carbon (활성탄에 의한 Reactive Orange 16 염료 흡착에 대한 공정 파라미터 연구)

  • Lee, Jong Jib
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.21 no.7
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    • pp.667-674
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    • 2020
  • The adsorption of reactive orange 16 (RO 16) dye by activated carbon was investigated using the amount of adsorbent, pH, initial concentration, contact time and temperature as adsorption variables. The investigated process parameters were separation coefficient, rate constant, rate controlling step, activation energy, enthalpy, entropy, and free energy. The adsorption of RO 16 was the highest at pH 3 due to the electrostatic attraction between the cations (H+) on the surface of the activated carbon and the sulfonate ions and hydroxy ions possessed by RO 16. Isotherm data were fitted into Langmuir, Freundlich and Temkin isotherm models by applying the evaluated separation factor of Langmuir (RL=0.459~0.491) and Freundlich (1/n=0.398~0.441). Therefore, the adsorption operation of RO 16 by activated carbon was confirmed as an appropriate removal method. Temkin's adsorption energy indicated that this adsorption process was physical adsorption. The adsorption kinetics studies showed that the adsorption of RO 16 follows the pseudo-second-order kinetic model and that the rate controlling step in the adsorption process was the intraparticle diffusion step. The positive enthalpy change indicated an endothermic process. The negative Gibbs free energy change decreased in the order of -3.16 <-11.60 <-14.01 kJ/mol as the temperature increased. Therefore, it was shown that the spontaneity of the adsorption process of RO 16 increases with increasing temperature.

Numerical Experiments of Coastal Upwelling Occurred by Summer Winds in the East Sea of Korea (한국 동해 연안에서 하계 바람에 의해 발생하는 연안용승에 관한 수치실험)

  • Seo, Ho-San;Lim, Woo-Hyun;Kim, Dong-Sun
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.23 no.4
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    • pp.347-353
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    • 2017
  • In this study, numerical experiments were conducted to identify distribution of rising flow and flux in the East Sea of Korea, where the coastal upwelling occurs. Temperature and salinity data from CTD observations and NIFS during summer 2013 were applied to the model. Numerical experiments were carried out with different wind speed (3, 6 m/s and 9 m/s) and direction (southerly and southwesterly), which represent the most frequent in summer conditions. As a result of calculation, upwelling flow rate was found to be highest in Pohang between five coasts(Hupo, Youngduk, Pohang, Ulsan and Busan). Comparing with southerly wind conditions, the rising flow rate is about 1.5 times greater when southwesterly wind was applied. Horizontal diffusion of the upwelling area is expected to have a speed of 17~22 km/day when a 9 m/s southwesterly wind is applied. If this wind continues over one week, a cold pool will be generated by upwelling that may reach to the Ulleung area.

The innovation diffusion and neighbors in the 4th wave through Dubai-city (두바이 도시혁신에 따른 주변국가의 4차산업 혁신확산)

  • Seo, Dae-Sung;Kim, Dong-Hwa
    • The Journal of Industrial Distribution & Business
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    • v.9 no.12
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    • pp.55-61
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    • 2018
  • Purpose - It suggests that making a policy and strategies for a way of Dubai has a strong priority strategy on science and technology by using much oil dollars to prepare risk when oil dollar's decrease. This has been now investigated how the leading innovator has changed the periphery countries. Research design, data, and methodology - Analyze policy, status, what other neighbouring Middle East countries also want to benchmark a successful case of a leading Dubai strategy. Higher manpower is needed absolutely to develop S&T. and etc. Dubai and Arab countries establish university to nurture as well as invite the talented manpower from overseas to recover deficient manpower. Dubai built totally academy city and invited branch of the overseas famous university, and Saudi Arabia built university(KAUST) and invite faculty and support good scholarship for students. Abrab countries especially, This is studied the process of differentiating and integrating the migrant workers of these cities into the globalized cities. This has resulted in large-scale employment for foreign and local companies in these cities and the spread of science and innovation. Results - Dubai supports venture or SMEs by using a strong priority strategy and attracts foreigner's investor, with which the neighbouring countries have been preparing together for 4th wave. It demonstrates that the gravitational model has been activated from neighboring countries of innovation science to create Dubai's hub. The maturity of long-term urban innovation is related to innovation capability through the national response and review. As a result, the flow of skilled international migration has been localized because of the mutual intersection with the local employment structure, and the development has spread as it spreads to neighboring countries. Conclusion - For the exploiting of new Distribution market in the neighbouring countries, Middle East countries' a strong priority strategy on S&T and education system give an influence on economic situation of the 4th wave in the world and world order of leading by USA, Japan, or EU, and etc. This is due to the creation of clusters in the form of SEZs, friendly industrial policies and world-class infrastructure and innovation development. Its neighbours benchmark the cases of distribution of science innovation and centralizes the surrounding people.

Socioeconomic development, gender equity and birthrate's determinant: focused on the family axis' transformation model (사회경제적 발전, 양성평등 그리고 출산율의 결정요인 -가족 중심축의 수평화 2단계 모형을 중심으로-)

  • Lee, Je-Sang;Song, Yoo-Mee
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.17 no.11
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    • pp.256-270
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    • 2016
  • This purpose of this study is to present a new theoretical framework on birthrate recovery in advanced countries in the 21st century. As a result of socioeconomic development and individualism diffusion, the central axis of the family has transformed from the vertical axis of the father-son relation, to the horizontal axis of the husband-wife relation. This process is divided into 2 stages. In the industrialization stage, a nation or a society achieves equality of the individual in family formation, including marriage or divorce. In the post-industrialization stage, it accomplishes the couple equality in family maintenance, including child rearing and household labor. This paper grouped 33 OECD member countries as post- industrialization countries and 103 countries as industrialization countries. This study utilizes 6 variables affecting marriage and childbearing based on previous research. Research results find that during the industrialization stage, the birthrate falls as the education level of women is higher. In the post-industrialization stage, the birthrate rises as gender equality level is higher.