• Title/Summary/Keyword: Dynamic management

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Knowledge Production Function in South Korea : An Empirical Analysis (우리나라 지식생산함수 : 실증분석)

  • Cho, Sang-Sup;Jung, Dong-Jin
    • Journal of Korea Technology Innovation Society
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    • v.10 no.3
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    • pp.383-405
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    • 2007
  • In this paper we estimate knowledge production function for 15 South Korean industry sectors using panel data. To accommodate the influence of inter-sectoral interactions on the creation of knowledge, we estimate parameters for related knowledge production functions using the Dynamic Seemingly Unrelated Regression(DSUR) model proposed by Mark et al. (2005). We find the elasticity of knowledge production with respect to the size of research staff to be 0.25 and that with respect to the existing stock of knowledge to be 0.35. The fact that the elasticity of new knowledge creation with regard to the existing knowledge stock is below 1 in South Korea corroborates the view that the rate of long-term growth of her economy is chiefly determined by the elasticity related to production functions of goods and services and the rate of population growth, and that her government policy, to ensure a continued growth for the Korean economy, must shift the focus of R&D policies from the current direct intervention-centered model to one consisting of indirect measures, namely supporting knowledge management and diffusion and the creation of a knowledge sharing system. In terms of R&D policy implications it could be consider that the national knowledge production system should strengthen the cumulative process of knowledge accumulation and population for research and development. Our country R&D policy, also, need to adopt a global approach to increase knowledge stock at the highest levels of a country.

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Forecasting the Grain Volumes in Incheon Port Using System Dynamics (System Dynamics를 이용한 인천항 양곡화물 물동량 예측에 관한 연구)

  • Park, Sung-Il;Jung, Hyun-Jae;Yeo, Gi-Tae
    • Journal of Navigation and Port Research
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    • v.36 no.6
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    • pp.521-526
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    • 2012
  • More efficient and effective volume management of trade cargo is recently requested due to FTA with foreign country. Above all, the grain is the main cargo needed in Korean food life and was appointed as the core trade cargo during FTA. This study is aimed to forecast future demands of grain volumes which are handled at Incheon port because most of the grain volumes are traded at Incheon port in Korea. System Dynamics (SD) was used for forecasting as the methodology. Also, population, yearly grain consumption per a man, GDP, GRDP, exchange rate, and BDI were used as the factors that influence grain volumes. Simulation duration was from 2000 to 2020 and real data was used from 2000 to 2007. According to the simulation, 2020's grain volumes at Incheon port were forecasted to be about 2 million tons and grain volumes handled at Incheon port were continuously reduced. In order to measure accuracy of the simulation, this study implemented MAPE analysis. And after the implementation, the simulation was decided as a much more accurate model because MAPE value was calculated to be 6.3%. This study respectively examined factors using the sensitivity analysis. As a result, in terms of the effects on grain volume in Incheon Port, the population factor is most significant and exchange rate factor is the least.

MAC Scheduling Algorithm for Efficient Management of Wireless Resources in Bluetooth Systems (블루투스 시스템에서의 효율적 무선자원관리를 위한 MAC 스케쥴링 기법)

  • 주양익;권오석;오종수;김용석;이태진;엄두섭;차균현
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.28 no.9A
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    • pp.702-709
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    • 2003
  • In this paper, we propose an efficient and QoS-aware MAC scheduling algorithm for Bluetooth, which considers both throughput and delay performance of each Master-Slave pair in scheduling decisions, and thus, attempts to maximize overall performance. The proposed algorithm, MTDPP (Modified Throughput-Delay Priority Policy), makes up for the drawbacks of T-D PP (Throughput-Delay Priority Policy) proposed in [6] and improves the performance. Since Bluetooth employs a master-driven TDD based scheduling algorithm, which is basically operated with the Round Robin policy, many slots may be wasted by POLL or NULL packets when there is no data waiting for transmission in queues. To overcome this link wastage problem, several algorithms have been proposed. Among them, queue state-based priority policy and low power mode-based algorithm can perform with high throughput and reasonable fairness. However, their performances may depend on traffic characteristics, i.e., static or dynamic, and they require additional computational and signaling overheads. In order to tackle such problems, we propose a new scheduling algorithm. Performance of our proposed algorithm is evaluated with respect to throughput and delay. Simulation results show that overall performances can be improved by selecting suitable parameters of our algorithm.

A Study of Improvement of Urban Pavement Maintenance Technique based on Pavement Condition Evaluation and FWD Data (도로포장 표면조사와 FWD정보에 기반한 도심지 도로포장 유지보수 기법 개선방안 연구)

  • Lee, Sangyum
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.17 no.12
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    • pp.532-541
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    • 2016
  • The objective of this paper is to support accurate pavement condition assessment and decision of proper maintenance method and time by conducting visual inspection and calculating the remaining life of pavement from falling weight deflectometer(FWD) data. Each was implemented in the same long-term performance pavement(LTPP) sections. Visual inspection was executed to measure pavement condition indices such as crack, rutting and international roughness index(IRI) and the Seoul Pavement Index(SPI) was calculated based on these results. The dynamic modulus was back-calculated from the FWD data. The remaining pavement lives were determined from equivalent single axle loading(ESAL) and FWD data. Correlation of maintenance priority by each result value was examined. Consequently, the correlation between remaining life to Crack and Rutting was higher than the other factors or indicesbecause IRI is not related to FWD value and SPI value consists with IRI value and other indices. The R-square value of correlation of FWD with Crack and Rutting was 0.65, which indicated an insufficient correlation. Consequently, when decision of maintenance of method, time, etc. is determined, FWD data have to be considered with Crack and Rutting because of those relations.

A Link Travel Time Estimation Algorithm Based on Point and Interval Detection Data over the National Highway Section (일반국도의 지점 및 구간검지기 자료의 융합을 통한 통행시간 추정 알고리즘 개발)

  • Kim, Sung-Hyun;Lim, Kang-Won;Lee, Young-Ihn
    • Journal of Korean Society of Transportation
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    • v.23 no.5 s.83
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    • pp.135-146
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    • 2005
  • Up to now studies on the fusion of travel time from various detectors have been conducted based on the variance raito of the intermittent data mainly collected by GPS or probe vehicles. The fusion model based on the variance ratio of intermittent data is not suitable for the license plate recognition AVIs which can deal with vast amount of data. This study was carried out to develop the fusion model based on travel time acquired from the license plate recognition AVIs and the point detectors. In order to fuse travel time acquired from the point detectors and the license plate recognition AVIs, the optimized fusion model and the proportional fusion model were developed in this study. As a result of verification, the optimized fusion model showed the superior estimation performance. The optimized fusion model is the dynamic fusion ratio estimation model on real time base, which calculates fusion weights based on real time historic data and applies them to the current time period. The results of this study are expected to be used effectively for National Highway Traffic Management System to provide traffic information in the future. However, there should be further studies on the Proper distance for the establishment of the AVIs and the license plate matching rate according to the lanes for AVIs to be established.

Analysis on the Temperature of Multi-core Processors according to Placement of Functional Units and L2 Cache (코어 내부 구성요소와 L2 캐쉬의 배치 관계에 따른 멀티코어 프로세서의 온도 분석)

  • Son, Dong-Oh;Kim, Jong-Myon;Kim, Cheol-Hong
    • Journal of the Korea Society of Computer and Information
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    • v.19 no.4
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    • pp.1-8
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    • 2014
  • As cores in multi-core processors are integrated in a single chip, power density increased considerably, resulting in high temperature. For this reason, many research groups have focused on the techniques to solve thermal problems. In general, the approaches using mechanical cooling system or DTM(Dynamic Thermal Management) have been used to reduce the temperature in the microprocessors. However, existing approaches cannot solve thermal problems due to high cost and performance degradation. However, floorplan scheme does not require extra cooling cost and performance degradation. In this paper, we propose the diverse floorplan schemes in order to alleviate the thermal problem caused by the hottest unit in multi-core processors. Simulation results show that the peak temperature can be reduced efficiently when the hottest unit is located near to L2 cache. Compared to baseline floorplan, the peak temperature of core-central and core-edge are decreased by $8.04^{\circ}C$, $8.05^{\circ}C$ on average, respectively.

Fine Grained Resource Scaling Approach for Virtualized Environment (가상화 환경에서 세밀한 자원 활용률 적용을 위한 스케일 기법)

  • Lee, Donhyuck;Oh, Sangyoon
    • Journal of the Korea Society of Computer and Information
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    • v.18 no.7
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    • pp.11-21
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    • 2013
  • Recently operating a large scale computing resource like a data center becomes easier because of the virtualization technology that virtualize servers and enable flexible resource provision. The most of public cloud services provides automatic scaling in the form of scale-in or scale-out and these scaling approaches works well to satisfy the service level agreement (SLA) of users. However, a novel scaling approach is required to operate private clouds that has smaller amount of computing resources than vast resources of public clouds. In this paper, we propose a hybrid server scaling architecture and related algorithms using both scale-in and scale-out to achieve higher resource utilization rate for private clouds. We uses dynamic resource allocation and live migration to run our proposed algorithm. Our propose system aims to provide a fine-grain resource scaling by steps. Thus private cloud systems are able to keep stable service and to reduce server management cost by optimizing server utilization. The experiment results show that our proposed approach performs better in resource utilization than the scale-out approach based on the number of users.

Assessment of Isokinetic Muscle Function, Balance and Flexibility in Elite High School Kayakers (고등학교 엘리트 카약 선수들의 등속성 근기능·균형성·유연성 측정 및 평가)

  • Shin, Kwang-Taek;Sohn, Jee-Hoon
    • Journal of Digital Convergence
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    • v.16 no.6
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    • pp.407-416
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    • 2018
  • The purpose of this study is to evaluate elite high school kayaker's iso-kinetic muscle function and provide physical training advices. Biodex system IV, Biodex stabilizer system, Inbody 3.0 and CNP-5403 are used to investigate 11 kayaker's muscle function(peak torque, average power and work fatigue), dynamic balance, body compositions, and flexibility. S4, S5, S8, S10, S11 are needed to train shoulder muscle strength and power. S5, S6, S10, S11 are needed to strengthen shoulder muscle endurance. S5, S7, S8, S10, S11 are needed to train knee muscle strength and power. S1, S4, S5, S10 are needed to strengthen knee muscle endurance. S3, S10, S11 are needed to train wrist muscle endurance. Based on these results we should establish an muscle function enhancing program with periodic inspection for elite kayakers. And standardized training program should be sublated.

Refinement of damage identification capability of neural network techniques in application to a suspension bridge

  • Wang, J.Y.;Ni, Y.Q.
    • Structural Monitoring and Maintenance
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    • v.2 no.1
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    • pp.77-93
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    • 2015
  • The idea of using measured dynamic characteristics for damage detection is attractive because it allows for a global evaluation of the structural health and condition. However, vibration-based damage detection for complex structures such as long-span cable-supported bridges still remains a challenge. As a suspension or cable-stayed bridge involves in general thousands of structural components, the conventional damage detection methods based on model updating and/or parameter identification might result in ill-conditioning and non-uniqueness in the solution of inverse problems. Alternatively, methods that utilize, to the utmost extent, information from forward problems and avoid direct solution to inverse problems would be more suitable for vibration-based damage detection of long-span cable-supported bridges. The auto-associative neural network (ANN) technique and the probabilistic neural network (PNN) technique, that both eschew inverse problems, have been proposed for identifying and locating damage in suspension and cable-stayed bridges. Without the help of a structural model, ANNs with appropriate configuration can be trained using only the measured modal frequencies from healthy structure under varying environmental conditions, and a new set of modal frequency data acquired from an unknown state of the structure is then fed into the trained ANNs for damage presence identification. With the help of a structural model, PNNs can be configured using the relative changes of modal frequencies before and after damage by assuming damage at different locations, and then the measured modal frequencies from the structure can be presented to locate the damage. However, such formulated ANNs and PNNs may still be incompetent to identify damage occurring at the deck members of a cable-supported bridge because of very low modal sensitivity to the damage. The present study endeavors to enhance the damage identification capability of ANNs and PNNs when being applied for identification of damage incurred at deck members. Effort is first made to construct combined modal parameters which are synthesized from measured modal frequencies and modal shape components to train ANNs for damage alarming. With the purpose of improving identification accuracy, effort is then made to configure PNNs for damage localization by adapting the smoothing parameter in the Bayesian classifier to different values for different pattern classes. The performance of the ANNs with their input being modal frequencies and the combined modal parameters respectively and the PNNs with constant and adaptive smoothing parameters respectively is evaluated through simulation studies of identifying damage inflicted on different deck members of the double-deck suspension Tsing Ma Bridge.

'Development' and 'Relations', as the Core Concepts of Home Economics in 2015 Revised Middle School Curriculum in Korea (2015 개정 가정과의 핵심개념 '발달과 관계' - 중학교 교육과정을 중심으로 -)

  • Lim, JungHa;Jun, Mi-Kyung
    • Journal of Korean Home Economics Education Association
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    • v.28 no.1
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    • pp.1-17
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    • 2016
  • The purpose of this review was to introduce and examine 'development' and 'relations' as the core concepts of Home Economics in 2015 revised middle school curriculum in Korea. The 2009 and 2015 proclamation of the ministry of education on home economics curriculum and 26 published middle school textbooks were reviewed. The major findings were as follows. First, the components of human 'development' and family 'relations' were strongly associated with promoting four key competencies (i.e. the self-management competency, the communication competency, the aesthetic sensibility competency, the community competency) of 2015 revision. Also, four of cross-curricular learning topics (i.e. character education, multicultural education, safety and health education, human right education) in 2015 revision could be effectively discussed with human 'development' and family 'relations'. Second, when teaching and learning of the core concept, human 'development', continuous dynamic aspects of life-span development, the connectedness of different domains of development, systematic approach of various concepts in development, specificity and empirical evidence of information and variability of developmental patterns in adolescence should be considered. Third, when teaching and learning of the core concept, family 'relations', family trait such as generational relations, gender relations, role relations and power relations should be taken into account. In addition, exclusively focusing on normal family ideology or image of middle-class family and lecture-centered instruction methods should be changed for students to achieve the competencies relevant to family relations. The future directions for applying core concepts, 'development' and 'relations' in classroom will be discussed.