• Title/Summary/Keyword: 대기모델

Search Result 1,709, Processing Time 0.023 seconds

The Study on the SEP (Standard Essential Patents) Procurement Strategy to accelerate the Trade Negotiation Competitiveness (통상 협상의 경쟁력 강화를 위한 표준특허 확보전략 연구)

  • Cho, Dongmin;Cho, Wongil
    • International Commerce and Information Review
    • /
    • v.18 no.4
    • /
    • pp.263-281
    • /
    • 2016
  • The Importance of SEP (Standard Essential Patents) Procurement Operation is on the side of Governmental and Public both to accelerate the national trade negotiation competitiveness. To operate cooperative system of SEP creation and management, Government should monitor the effect and performance periodically to public sectors. and To achieve the support objectives, it should establish the virtuous circle infrastructure between R&D and economic performance on SEP. This can make the SEP enhancement to pursue the international competitiveness on Intellectual Property Rights. Especially the specific support approach to each phase of the SEP declaration matrix is essential to consolidate the possibility of SEP creation and acquisition. In this study, the concepts of SEP to accelerate the national trade negotiation competitiveness and the prior research were verified through the investigation of market trend and current state of affair analysis. Through the analysis of international and domestic situation of SEP procurement and management, We have found the results as follows. First of all, the leading conglomerates and the Government should focus on the secondary and tertiary industries to create and acquire SEPs to accomplish the effectiveness of selection and concentration. In second, the SMEs and Univ. Labs should focus on the quaternary sector of the economy to retain the competitiveness of speed and challenge on SEP related. From this study, the appropriateness of the tailored-support management model should be institutionalized, and the results implied an research in order to examine the suitability among the current SEP to enhance the competitiveness of national trade research issues.

  • PDF

Estimating distribution changes of ten coastal plant species on the Korean Peninsula (한반도 해안식물 10종의 분포 변화 추정)

  • PARK, Jong-Soo;CHOI, Byoung-Hee
    • Korean Journal of Plant Taxonomy
    • /
    • v.50 no.2
    • /
    • pp.154-165
    • /
    • 2020
  • Coastal regions are experiencing habitat changes due to coastal development and global warming. To estimate the future distribution of coastal plants on the Korean Peninsula due to climate change, the potential distribution of ten species of coastal plants was analyzed using the MaxEnt program. The study covered the eastern, western, and southern coastal areas of the Korean Peninsula. We used the distributional data of coastal plants of the East Asian region and the 19 climate variables of WorldClim 2.0. The future potential distribution was estimated using future climate variables projected from three general circulation models (CCSM4, MIROC-ESM, and MPI-ESM-LR), four representative concentration pathways (2.5, 4.5, 6.0, and 8.5), and two time periods (2050 and 2070). The annual mean temperature influenced the estimation of the potential distribution the most. Under predicted future distribution scenarios, Lathyrus japonicus, Glehnia littoralis, Calystegia soldanella, Vitex rotundifolia, Scutellaria strigillosa, Linaria japonica, and Ixeris repens are expected to show contracted distributions, whereas the distribution of Cnidium japonicum is expected to expand. Two species, Salsola komarovii and Carex kobomugi, are predicted to show similar distributions in the future compared to those in the present. The average potential distribution in the future suggests that the effects of climate change will be greater in the west and the south coastal regions than in the east coastal region. These results will be useful baseline data to establish a conservation strategy for coastal plants.

The Effect of Coal Particle Size on Char-$CO_{2}$ Gasification Reactivity by Gas Analysis (가스분석을 이용한 석탄 입자크기가 촤-$CO_{2}$ 가스화 반응성에 미치는 영향 연구)

  • Kim, Yong-Tack;Seo, Dong-Kyun;Hwang, Jung-Ho
    • Korean Chemical Engineering Research
    • /
    • v.49 no.3
    • /
    • pp.372-380
    • /
    • 2011
  • Char gasification is affected by operating conditions such as reaction temperature, reactants gas partial pressure, total system pressure and particle size in addition to chemical composition and physical structure of char. The aim of the present work was to characterize the effect of coal particle size on $CO_{2}$ gasification of chars prepared from two different types of bituminous coals at different reaction temperatures(1,000-$1,400{^{\circ}C}$). Lab scale experiments were carried out at atmospheric pressure in a fixed reactor where heat was supplied into a sample of char particles. When a flow of $CO_{2}$(40 vol%) was delivered into the reactor, the char reacted with $CO_{2}$ and was transformed into CO. Carbon conversion of the char was measured using a real time gas analyzer having NDIR CO/$CO_{2}$ sensor. The results showed that the gasification reactivity increased as the particle size decreased for a given temperature. The sensitivity of the reactivity to particle size became higher as the temperature increases. The size effects became remarkably prominent at higher temperatures and became a little prominent for lower reactivity coal. The particle size and coal type also affected reaction models. The shrinking core model described better for lower reactivity coal, whereas the volume reaction model described better for higher reactivity coal.

A Study of the Urban Tree Canopy Mean Radiant Temperature Mitigation Estimation (도시림의 여름철 평균복사온도 저감 추정 연구)

  • An, Seung Man;Son, Hak-gi;Lee, Kyoo-Seock;Yi, Chaeyeon
    • Journal of the Korean Institute of Landscape Architecture
    • /
    • v.44 no.1
    • /
    • pp.93-106
    • /
    • 2016
  • This study aimed to estimate and evaluate the thermal mitigation of the urban tree canopy on the summer outdoor environment by quantitative use of mean radiant temperature. This study applied the SOLWEIG model based $T_{mrt}$ comparison method by using both (1) urban tree canopy presence examples and (2) urban tree canopy absence examples as constructed from airborne LiDAR system based three-dimensional point cloud data. As a result, it was found that an urban tree canopy can provide a decrease in the entire domain averaged daily mean $T_{mrt}$ about $5^{\circ}C$ and that the difference can increase up to $33^{\circ}C$ depending both on sun position and site conditions. These results will enhance urban microclimate studies such as indices (e.g., wind speed, humidity, air temperature) and biometeorology (e.g., perceived temperature) and will be used to support forest based public green policy development.

BGK 수치기법을 이용한 로켓 노즐 내의 유동장 해석

  • 신동신;이재성
    • Proceedings of the Korean Society of Propulsion Engineers Conference
    • /
    • 2000.04a
    • /
    • pp.16-16
    • /
    • 2000
  • 충격파를 포함하는 초음속 유동을 해석하는 수치해법 중에서 많이 사용되어진 것은 엄밀 및 근사 리만 해법과 플럭스 분할 기법들로서 이들은 Euler 방정식에 기반을 두고 선형 또는 비선형파의 상호작용을 풍상 차분법으로 기술하는 방법들이다. 이러한 수치기법들은 과거 광범위하게 사용되어 왔으나 최근 여러 가지 단점이 발견되었다. 이와 같은 문제점을 극복하고자 입자의 통계적인 운동을 기술하는 기체 운동론에 근거하여 BGK 수치기법이 제시되었다. 이는 비충돌 볼츠만 방정식으로부터 입자의 수준에서 플럭스 분할 기법 형태의 풍상차분법을 구현하는 것으로 볼츠만 방정식의 충돌항을 BGK 모델로 대치하고 이것의 적분해로부터 수치 플럭스를 구한다. 이 수치기법은 기존의 리만해법에 비하여 수치적으로나 물리적으로 매우 타당한 성질인 강건성, 정확성, 엔트로피 조건, 양수보존성 등을 가지고 있음이 밝혀졌다. 이와 같은 수치기법을 사용하여 로켓 노즐 내의 아음속, 천이음속, 초음속에서의 유동장 해석을 위한 프로그램을 작성하였다. 시간 적분에 대하여는 정상 상태의 계산을 위하여 내재적 시간 적분 방법을 사용하였으며, 공간 이산화 방법으로는 임의의 제어체적에 대하여 적분형 보존 방정식을 적용하는 유한 체적법을 사용하였다. 초음속 입구 유동과 출구에서 초음속과 저음속 유동의 두가지 경우를 고려하여 얻은 결과를 기존의 연구 결과와 비교하여 본 결과 잘 일치하였다. 입구 유동이 저음속이고 출구 유동이 초음속인 경우에 대하여도 해석결과가 실험결과와 잘 일치하였다. 상대적으로 낮은 온도, 압력 조건과 높은 온도, 압력 조건을 가지는 고체 로켓 모터 노즐 내의 유동을 해석하였다. 이들 해석 결과를 전압, 전온도로 표준화시킨 결과 서로 일치하였으며, 파라서 저온, 저압에서 얻은 결과도 표준화시킬 경우, 고온, 고압에서도 사용될 수 있음을 알 수 있었다.의 영향에 초점을 맞추었다.다고 판단되며 배기 가스 자체에 대기 공기중에 함유되어 있던 습기가 얼어붙는(Icing화) 문제가 발생하기 때문에 배기가스의 Icing을 방지하기 위하여 압축기 끝단에서 공기를 추출하여 배기부분에 송출할 필요성이 있는 것으로 판단되었다. 출구가스의 기체 유동속도가 매우 빠르므로 (100-l10m.sec) 이를 완화하기 위한 디퓨저의 설계가 요구된다고 판단된다. 또 연소기 후방에 물을 주입하는 경우 열교환기 및 기타 부분품에 발생할 수 있는 부식 및 열교환 효율 저하도 간과할 수 없는 문제로 파악되었다. 이러한 기술적 문제가 적절히 해결되는 경우 비활성 가스 제너레이터는 민수용으로는 대형 빌딩, 산림, 유조선 등의 화재에 매우 적절히 사용되어 질 수 있을 뿐 아니라 군사적으로도 군사작전 중 및 공군 기지의 화재 그리고 지하벙커에 설치되어 있는 고급 첨단 군사 장비 등의 화재 뿐 아니라 대간첩작전 등에 효과적으로 활용될 수 있을 것으로 판단된다.가 작으며, 본 연소관에 충전된 RDX/AP계 추진제의 경우 추진제의 습기투과에 의한 추진제 물성 변화는 미미한 것으로 나타났다.의 향상으로, 음성개선에 효과적이라고 사료되었으며, 이 방법이 편측 성대마비 환자의 효과적인 음성개선의 치료방법의 하나로 응용될 수 있으리라 생각된다..7%), 혈액투석, 식도부분절제술 및 위루술·위회장문합술을 시행한 경우가 각 1례(2.9%)씩이었다. 13) 심각한 합병증은 9례(26.5%)에서 보였는데 그중 식도협착증이 6례(17.6%), 급성신부전증 1례(2.9%), 종격동기흉과 폐염이 병발한 경우와 폐염이 각 1례(2.9%)였다. 14) 식도경 시행회수는 1회가 17례(54.8%), 2회가 9례(29.0%), 3회 이상이 5례(16.1%)였다.EX>$IC_{50}$/ 값이 210 $\mu\textrm{g}$<

  • PDF

The Development of Predictive Multiclass Dynamic Traffic Assignment Model and Algorithm (예측적 다중계층 동적배분모형의 구축 및 알고리즘 개발)

  • Kang, Jin-Gu;Park, Jin-Hee;Lee, Young-Ihn;Won, Jai-Mu;Ryu, Si-Kyun
    • Journal of Korean Society of Transportation
    • /
    • v.22 no.5
    • /
    • pp.123-137
    • /
    • 2004
  • The study on traffic assignment is actively being performed which reflect networks status using time. Its background is increasing social needs to use traffic assignment models in not only hardware area of road network plan but also software area of traffic management or control. In addition, multi-class traffic assignment model is receiving study in order to fill a gap between theory and practice of traffic assignment model. This model is made up of two, one of which is multi-driver class and the other multi-vehicle class. The latter is the more realistic because it can be combined with dynamic model. On this background, this study is to build multidynamic model combining the above-mentioned two areas. This has been a theoretic pillar of ITS in which dynamic user equilibrium assignment model is now made an issue, therefore more realistic dynamic model is expected to be built by combining it with multi-class model. In case of multi-vehicle, FIFO would be violated which is necessary to build the dynamic assignment model. This means that it is impossible to build multi-vehicle dynamic model with the existing dynamic assignment modelling method built under the conditions of FIFO. This study builds dynamic network model which could relieve the FIFO conditions. At the same time, simulation method, one of the existing network loading method, is modified to be applied to this study. Also, as a solution(algorithm) area, time dependent shortest path algorithm which has been modified from existing shortest path algorithm and the existing MSA modified algorithm are built. The convergence of the algorithm is examined which is built by calculating dynamic user equilibrium solution adopting the model and algorithm and grid network.

A Study on Analyzing the Validity between the Predicted and Measured Concentrations of VOCs in the Atmosphere Using the CalTOX Model (CalTOX 모델에 의한 휘발성유기화합물의 대기 중 예측 농도와 실측 농도간의 타당성 분석에 관한 연구)

  • Kim, Ok;Lee, Minwoo;Park, Sanghyun;Park, Changyoung;Song, Youngho;Kim, Byeongbin;Choi, Jinha;Lee, Jinheon
    • Journal of Environmental Health Sciences
    • /
    • v.46 no.5
    • /
    • pp.576-587
    • /
    • 2020
  • Objectives: This study calculated local residents exposures to VOCs (Volatile Organic Compounds) released into the atmosphere using the CalTOX model and carried out uncertainty analysis and sensitivity analysis. The model validity was analyzed by comparing the predicted and the actual atmospheric concentrations. Methods: Uncertainty was parsed by conducting a Monte Carlo simulation. Sensitivity was dissected with the regression (coefficients) method. The model validity was analyzed by applying r2 (coefficient of determination), RMSE (root mean square error), and the Nash-Sutcliffe EI (efficiency index) formula. Results: Among the concentrations in the atmosphere in this study, benzene was the highest and the lifetime average daily dose of benzene and the average daily dose of xylene were high. In terms of the sensitivity analysis outcome, the source term to air, exposure time, indoors resting (ETri), exposure time, outdoors at home (ETao), yearly average wind speed (v_w), contaminated area in ㎡ (Area), active breathing rate (BRa), resting breathing rate (BRr), exposure time, and active indoors (ETai) were elicited as input variables having great influence upon this model. In consequence of inspecting the validity of the model, r2 appeared to be a value close to 1 and RMSE appeared to be a value close to 0, but EI indicated unacceptable model efficiency. To supplement this value, the regression formula was derived for benzene with y=0.002+15.48x, ethylbenzene with y ≡ 0.001+57.240x, styrene with y=0.000+42.249x, toluene with y=0.004+91.588x, and xylene with y=0.000+0.007x. Conclusions: In consequence of inspecting the validity of the model, r2 appeared to be a value close to 1 and RMSE appeared to be a value close to 0, but EI indicated unacceptable model efficiency. This will be able to be used as base data for securing the accuracy and reliability of the model.

A Case Study on Joint Overseas Expansion of Home Shopping Firm and Consumer Goods SMEs (홈쇼핑 기업과 소비재 중소기업의 해외 동반진출에 관한 사례연구)

  • Yang, Heesoon;Jeong, So Won;Chung, Jae-Eun
    • Asia-Pacific Journal of Business Venturing and Entrepreneurship
    • /
    • v.13 no.3
    • /
    • pp.153-165
    • /
    • 2018
  • There must be a balanced development of both conglomerates and small and mid-sized companies in order to secure constant economic growth and competitive edge of South Korea. Accordingly, high expectations are being placed on win-win growth and joint overseas expansion of conglomerates and small and mid-sized companies. This study seeks efficient ways to promote joint overseas expansion of major retailers and small and mid-sized companies considering the distinctiveness of home shopping by conducting interviews about joint overseas expansion of home shopping companies and small and mid-sized consumer goods companies in South Korea. To do this, interviews were conducted with three home shopping companies and three consumer goods SMEs operating in overseas markets. The results are as follows. Home shopping companies contribute to opening up overseas markets for small and mid-sized consumer goods companies, and allows them to make use of business and marketing competencies that they lack. Home shopping companies also produce visual materials or provide language translations, and help draw up documents for customs clearance in trading. They also form market development teams and provide information about the overseas markets. However, since the actual benefits from joint overseas expansion are minor for home shopping companies, there is a need for a strategy for win-win growth of both parties in the long run. To this end, it is necessary to provide substantial benefits to encourage joint overseas expansion. Ultimately, balanced development between home shopping companies and small- and medium-sized consumer goods companies should be promoted.

Study on VC Investment Improve Growth and Productivity of VC: Backed firms Focused on Kosdaq Listed Bio Venture Company (코스닥 상장 바이오벤처기업에 대한 벤처캐피탈 투자가 바이오벤처기업의 경영성과에 미치는 영향에 관한 연구)

  • Shin, Jin-O;Ha, Gyu-Soo
    • Asia-Pacific Journal of Business Venturing and Entrepreneurship
    • /
    • v.11 no.1
    • /
    • pp.85-95
    • /
    • 2016
  • Generally a venture capital aims at investment and support Venture businesses that signifies a start-up which has high technologies but frailty of the economy so that raise fund from financial agencies at high risk rate, it has high risk but when the venture businesses launch into general orbit, the venture capital guarantee high-rate profits. Venture capital do not just provide risk capital but also takes a role as a mentor for continuous growth with total consulting service at business and technical management. Also it offers in-depth support to reform the supported enterprise in order to enhance the competitive. Venture capital receives attention for years as a principal agent to be promoted strategically at national level. Bio venture, a major concern of venture capital and one of core industries in Korea, is different from other industries because it needs long-term and large scale of investment. these factors bring about difficulties in an investment and growth. Therefore, it is very important to identify growth and profitability of start-ups and small and venture businesses with long-term appreciation above all other industries. This research analyze management results of bio venture businesses empirically by investment from venture capital. according to the results, bio venture businesses need huge capital and a long gap of time, henceforth, formation of model for growth is necessary with angel investing as well as venture capital. Since, there are not many listed bio venture businesses, significant statistical result would be limited. This research studied at only economic focus but further study need to examine a question from various angles.

  • PDF

Syntaxonomical Characteristics of Abandoned Paddy Fields by Seral Stages in South Korea (우리나라에서 휴경기간에 따른 묵논의 군락분류 및 특성)

  • Shim, In-Su;Kim, Hong-Bong;Cho, Kwang-Jin
    • Korean Journal of Environmental Agriculture
    • /
    • v.32 no.3
    • /
    • pp.185-192
    • /
    • 2013
  • BACKGROUND: As a result of rural exodus, aging of rural population, development of high-yield rice varieties and so on, abandoned paddy fields of South Korea have generally increased. The phytosociological studies are needed to recommend the effective vegetation management methods of abandoned paddy fields. The current study performed an analysis of vegetation characteristics by classifying plant communities for abandoned paddy fields in South Korea. METHODS AND RESULTS: A comparative analysis of syntaxonomy, synecology, and syndynamics was performed by using the Z.-M. method of phytosociology and vegetation survey which was obtained from an enumeration district of total 203 phytosociological releves of 5 regions in Gangwon-do, 5 regions in Gyeonggi-do, 2 regions in Chungcheong-do, 18 regions in Gyeongsang-do, and 10 regions in Jeolla-do. Alopecurus aequalis community, Juncus effusus var. decipiens community and Salix koreensis community were, respectively, identified as successional plant communities of the early stage, the middle stage, and the late stage in the vegetation of abandoned paddy field. Sere of abandoned paddy field can be classified, developmentally, into annual plant stage, perennial plant stage, shrub plant stage, and forest tree stage. Several kinds of dominant species rather than a distinct species were found in the middle stage of abandoned paddy field. CONCLUSION(S): In this study, changing pattern in vegetational communities of abandoned paddy field were understood. These results will provide important information for restoring and conserving the ecology of fallow ground.