• Title/Summary/Keyword: 동력계 모델

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Development and Application of an Evaluation Model for Ubiquitous City Project (U-City 사업평가모델 개발 및 활용방안)

  • Kim, Byoung-Gun;Kim, Jung-Hun;Lee, Choon-Seong
    • The Journal of Society for e-Business Studies
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    • v.17 no.2
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    • pp.87-104
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    • 2012
  • Ubiquitous City is emerging as a new paradigm in future city development. U-City is nationwide project for future strategy to implement sustainable city environment and solve several issues in urban area. And as worldwide leading role on future city research, there are lots of U-City related researches in Government and Industry sector. However, it has raised unsustainable development concerns that indiscriminate promotion and visibility for long-term effects because it is not conducted an assessment. Thus, to overcome these problems and in order to develop a more stable U-City project, need to a fundamental consideration about U-City evaluation. This study is to provide the evaluation framework for Ubiquitous City(U-City). The framework is consisted of evaluation dimensions derived from characteristics of U-City development project. From this research, we expect it helps U-City development to be inspected and managed.

AN ORBIT PROPAGATION SOFTWARE FOR MARS ORBITING SPACECRAFT (화성 근접 탐사를 위한 우주선의 궤도전파 소프트웨어)

  • Song, Young-Joo;Park, Eun-Seo;Yoo, Sung-Moon;Park, Sang-Young;Choi, Kyu-Hong;Yoon, Jae-Cheol;Yim, Jo-Ryeong;Kim, Han-Dol;Choi, Jun-Min;Kim, Hak-Jung;Kim, Byung-Kyo
    • Journal of Astronomy and Space Sciences
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    • v.21 no.4
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    • pp.351-360
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    • 2004
  • An orbit propagation software for the Mars orbiting spacecraft has been developed and verified in preparations for the future Korean Mars missions. Dynamic model for Mars orbiting spacecraft has been studied, and Mars centered coordinate systems are utilized to express spacecraft state vectors. Coordinate corrections to the Mars centered coordinate system have been made to adjust the effects caused by Mars precession and nutation. After spacecraft enters Sphere of Influence (SOI) of the Mars, the spacecraft experiences various perturbation effects as it approaches to Mars. Every possible perturbation effect is considered during integrations of spacecraft state vectors. The Mars50c gravity field model and the Mars-GRAM 2001 model are used to compute perturbation effects due to Mars gravity field and Mars atmospheric drag, respectively. To compute exact locations of other planets, JPL's DE405 ephemerides are used. Phobos and Deimos's ephemeris are computed using analytical method because their informations are not released with DE405. Mars Global Surveyor's mapping orbital data are used to verify the developed propagator performances. After one Martian day propagation (12 orbital periods), the results show about maximum ${\pm}5$ meter errors, in every position state components(radial, cross-track and along-track), when compared to these from the Astrogator propagation in the Satellite Tool Kit. This result shows high reliability of the developed software which can be used to design near Mars missions for Korea, in future.

A Study of Accelerator Investment Determinants Based on Business Model Innovation Framework (비즈니스 모델 혁신 프레임워크 기반의 액셀러레이터 투자결정요인 연구)

  • Jung, Mun-Su;Kim, Eun-Hee
    • Asia-Pacific Journal of Business Venturing and Entrepreneurship
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    • v.17 no.2
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    • pp.65-80
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    • 2022
  • Despite the uncertainty and risky factors of startups, the special and critical role of accelerators in carrying out professional nurturing and investment for them is becoming increasingly significant in the startup social-system. However, academic research on investment determinants that have a profound impact on the survival of accelerators is lacking, and there are only a few empirical studies on the classification and importance of factors, and they do not enjoy the benefits of theoretical studies. This study proposes a business model innovation framework based on the business model innovation theory that reflects the nature and properties of startups that are investment targets of accelerators and derives 12 investment decision factors. The framework defines that the target, direction, and performable force of startup innovation are a business model, strategy, and dynamic capability. Besides, the framework analyzes the investment decision factors of the existing accelerators based on the business model innovation framework to verify the suitability and sufficiency of the composition. As a result of the analysis, first, most of the items were faithfully composed from a static point of view of business model innovation, but it was found that the factors related to the core activities to evaluate the activity and customer relationship were insufficient. Second, from the strategic point of view, the necessity of developing factors that can encompass the definition and content of core resources, which are internal strategic factors, was raised. Third, from the dynamic point of view, it was found that many of the investment determinants of accelerators were concentrated on the lower level of dynamic competencies. This can be judged as a result of reflecting the characteristics of a startup that needs to develop a solution with few resources and a small number of team members. In addition, the roles and interrelationships between each factor are not clear, thus it was found as a limiting point for startups to view and evaluate the direction and process in which startups dynamically innovate their business models. This study is considerably differentiated in that it provides a business model innovation framework and offers a theoretical basis for investment determinants by deriving the investment determinants of accelerators based on the framework and design the foundation for subsequent research. The business model innovation framework presented in this study has great implications in that it contributes to the achievement of startups, accelerators, and startup support organizations.

Characteristics and Parameters for Adsorption of Carbol Fuchsin Dye by Coal-based Activated Carbon: Kinetic and Thermodynamic (석탄계 활성탄에 의한 Carbol Fuchsin의 흡착 특성과 파라미터: 동력학 및 열역학)

  • Lee, Jong Jib
    • Applied Chemistry for Engineering
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    • v.32 no.3
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    • pp.283-289
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    • 2021
  • Adsorption characteristics of carbol fuchsin (CF) dye by coal-based activated carbon (CAC) were investigated using pH, initial concentration, temperature and contact time as adsorption variables. CF dissociates in water to have a cation, NH2+, which is bonded to the negatively charged surface of the activated carbon in the basic region by electrostatic attraction. Under the optimum condition of pH 11, 96.6% of the initial concentration was adsorbed. Isothermal adsorption behavior was analyzed using Langmuir, Freundlich, Temkin and Dubinin-Radushkevich models. Langmuir's equation was the best fit for the experimental results. Therefore, the adsorption mechanism was expected to be adsorbed as a monolayer on the surface of activated carbon with a uniform energy distribution. From the evaluated Langmuir's dimensionless separation coefficients (RL = 0.503~0.672), it was found that CF can be effectively treated by activated carbon. The adsorption energies determined by Temkin and Dubinin-Radushkevich models were E = 15.31~7.12 J/mol and B = 0.223~0.365 kJ/mol, respectively. Therefore, the adsorption process was physical (E < 20 J/mol, B < 8 kJ/mol). The experimental result of adsorption kinetics fit better the pseudo second order model. In the adsorption reaction of CF dye to CAC, the negative free energy change increased as the temperature increased. It was found that the spontaneity also increased with increasing temperature. The positive enthalpy change (40.09 kJ/mol) indicated an endothermic reaction.

분무진공동결건조기 개발

  • Ryu, Gyeong-Ha;Ban, Byeong-Min;Kim, Jae-Hyeong;Son, Sang-Ho
    • Proceedings of the Korean Vacuum Society Conference
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    • 2013.02a
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    • pp.258-258
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    • 2013
  • 최근 건조 제품의 양질화, 고급화 및 편의화가 요구되어 이를 충족시키기 위한 새로운 건조방법이 계속 개발 되어 왔다. 이러한 방법들 중에서 저온과 진공하에서 건조가 이루어지는 진공 동결 건조는 가장 완벽한 건조 방법으로 최근 실용화 되고 있다. 진공동결건조란 건조의 한 종류로 수분을 함유한 시료를 동결시킨 후 진공펌프를 이용하여 수증기압을 3중점 이하로 낮추어 얼음을 직접 증기로 만드는 승화의 원리에 의해서 얻어진다. 분무진공동결건조의 특징은 (1) 물리적구조의 보존성, (2) 화학적인 안정성, (3) 생물학적인 활동의 보존성, (4) 제품의 높은 복원성 및 재생성이다. 따라서 분무진공동결건조 기술은 크게 진공, 분무, 동결, 건조, 멸균 등과 같은 요소기술의 복합기술이라 할 수 있다. 분말을 제조하기 위해서 진공동결건조 후 분쇄하는 방법을 사용하나 본 방법에서는 정밀화학품 제조를 위해서 분무진공동결건조 방식을 사용한다. 이를 통하여 적당한 크기인 5~10 um의 입경 제조가 가능하고, 공기동력학적인 입경이 기존 방식에 비해 작아서 허파까지의 운반효율이 1.5~2배 우수하다. 화학, 의학 분야에서의 분무동결 건조는 주로 민감한 제품, 즉 생물학적 고유성의 손상 없이 물을 제거하는데 사용되어 영구적으로 저장 가능한 상태로 보관할 수 있으며 물의 첨가로 원상태로 복구할 수 있어서 매우 각광을 받고 있다. 의약용 냉동건조 제품은 항생물질, 박테리아, 혈청, 백신, 검사 약물, 단백질을 포함하는 생물공학 제품들, 세포, 섬유, 화학제품 등이 있으며 주로 vial 또는 ampule 상태로 건조가 이루어진다.본 연구에서는 원료를 $-194^{\circ}C$의 액체질소에 분무시켜 동결된 미립자를 형성한 후 진공 및 저온상태에서얼음의 승화(sublimation)에 기반한 1차 건조와 수증기 탈착(desorption)에 기초한 2차 건조 과정으로 구성된 분무진공동결건조기를 개발하였다. 분무동결 과정의 해석을 통해 2유체식 노즐을 통해 분무된 미세 입경의 액적이 액체 질소 표면까지 도달하는 회수률, 분무 노즐의 위치, 운전 조건 및 용기의 설계의 최적화를 수행하였다. 초기 액적속도, 분무노즐의 높이, 흡입구 추가에 따른 액적 유동 및 회수의 특성을 제시하였으며 이를 통한 분사시스템 고도화 가능성을 제시하였다. 구형의 미세 입자가 적층된 제품의 동결건조 공정의 해석은 흡착승화 모델(sorption sublimation model)을 기반으로 다음과 같은 열전달, 물질전달, 상변화 모델을 고려하여 유도되었다. 분무노즐 및 냉동/진공 배기계 시작품을 개발하여, 표면의 고다공도를 갖춘 입경 3~20 m 정도의 시료를 얻을 수 있으며, 동역학적 입경 5 m 충족함을 확인하였다.

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A Study on Measures to Create Local Webtoon Ecosystem (지역웹툰 생태계 조성을 위한 방안 연구)

  • Choi, Sung-chun;Yoon, Ki-heon
    • Cartoon and Animation Studies
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    • s.51
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    • pp.181-201
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    • 2018
  • The cartoon industry in Korea has continued to decline due to the contraction of published comics market and decrease in the number of comic books rental stores until the 2000s when it rapidly started to experience qualitative changes and quantitative growth due to the emergence of webtoon. The market size of webtoon industry, valued at 420 billion won in 2015, is expected to grow to 880.5 billion won by 2018. Notably, most cartoonists who draw cartoon strips are using digital devices and producing scripts in data, thereby overcoming the geographical, spatial and physical limitation of contents. As a result, a favorable environment for the creation of local ecosystems is generated. While the infrastructures of human resources are steadily growing by region, cartoon industries that are supported by the government policy have shown good performance combined with factors of creative infrastructures in local areas such as webtoon experience centers, webtoon campuses and webtoon creation centers, etc. Nevertheless, it is true that cartoon infrastructures are substantially based on a capital area which leads to an imbalanced structure of cartoon industry. To see the statistics, companies of offline cartoon business in Seoul and Gyeonggi Province make up 87%, except for distribution industry. In addition, companies of online cartoon business which are situated outside of Seoul and Gyeonggi Province form merely 7.5%. Studies and research on local webtoon are inadequate. The existing studies on local webtoon usually focus on its industrial and economic values, mentioning the word "local" only sometimes. Therefore, this study looked into the current status of local webtoon of the present time for the current state of local cartoon ecosystem, middle and long-term support from the government, and an alternative in the future. Main challenges include the expansion of opportunities to enjoy cartoon cultures, the independence of cartoon infrastructure, and the settlement of regionally specialized cartoon cultures. It means that, in order to enable the cartoon ecosystem to settle down in local areas, it is vital to utilize and link basic infrastructures. Furthermore, it is necessary to consider independence and autonomy beyond the limited support by the government. Finally, webtoon should be designated as a culture, which can be a new direction of the development of local webtoon. Furthermore, desirable models should be continuously researched and studied, which are suitable for each region and connect them with regional tourism, culture and art industry. It will allow the webtoon industry to soft land in the industry. Local webtoon, which is a growth engine of regions and main contents of the fourth industrial revolution, is expected to be a momentum for the decentralization of power and reindustrialization of regions.