• Journal of the Korea Institute of Military Science and Technology
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• v.23 no.5
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• pp.475-484
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• 2020

Individual curing process of each layer in two resin composites can be caused the separation between two layers. In this study, co-curing process for two resin composites is suggested to improve the inter-layer bonding. Glass fiber reinforced composites with phenolic and epoxy resins were manufactured by co-curing process, and several types of glass/phenolic composites were considered to confirm the application on two resin composites. Experiments for smoke resistance, scratch resistance and flexural strength were carried out to verify requirements corresponding to thermal and mechanical environments. It was validated that two resin composites with phenolic resin impregnated prepreg exhibits good thermal and mechanical characteristics, and it can serve as highly effective composite structures in aerospace and many industry areas.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.14 no.2
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• pp.93-100
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• 2014

IEEE 802.11 Wireless LAN Medium Access Control(MAC) supports two transmission methods, a DCF basic and a RTS/CTS in contention-based access. Even though the RTS/CTS method has been optionally introduced to solve the hidden terminal problem, it is able to produce better performance in some network environments than the basic transmission method. In this paper, the collision probability of wireless channel is mathematically analyzed and applied to measure network throughput using real transmission parameters so that a reference value between throughputs of two methods is obtained. We also confirmed that control signal rates affect overall network throughput and evaluated network throughputs considering collision probability, number of stations, and contention window size of Backoff between two methods respectively.

• Journal of Environmental Science International
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• v.6 no.6
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• pp.637-644
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• 1997

The purpose of thins study was to quantitatively determine the Indoor Infiltration of pollutants of outdoor origin. The relationship between Indoor and outdoor air is dependent, to a large extent. on the rate of k exchange between these two environments. Mean Indoor/outdoor ratios measured from thins study were: 0.70 for HNO3; 1.60 for HNO2: 0.56 far SOg: 1.30 for mf3: 0.96 for PM2.5(dP<2.5mm: 0.89 for SO4a': 0.87 for NO3· and 0.79 for NH4 'Mean Indoor concentrations for PMa s, SO4a., HNO9, NO3 and NIL' were similar to outdoor levels. Indoor HNO2 and mB3 values were h19her than outdoors. However, the Indoor level of SO2 was lower than ambient level.

• Journal of Information Technology Services
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• v.10 no.4
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• pp.219-227
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• 2011

Service Oriented Architecture (SOA) is rapidly emerging as the efficient approach in contemporary complex, heterogeneous computing environments. SOA increases the adaptability by loose coupling and its main feature is that three elements such as service provider, service requester and service registry are connected with each other systematically. To design the service-oriented system efficiently, a metric to measure the coupling between services accurately is needed. In this paper, we propose four coupling metrics for SOA based softwares. First, we suggest a coupling metric for service-oriented systems by modifying an established coupling metric of object-oriented systems. Then we suggest another coupling metric which includes indirect coupling between services. We also suggest two relative coupling metrics to measure coupling between subsystems. We investigate the theoretical soundness of the proposed metrics by the axioms of Briand et al. Finally, we apply the presented metrics to an industrial-scale case study.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.22 no.6
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• pp.1356-1364
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• 1997

This paper presents a modelling and implementation scheme of a multi directory which provides location and supplementary information of multiple applications in distributed environments. An extrended directory schema and extended DIT(Directory Information Tree) model is proposed for the multi directory. For implementation scheme, an implementation example adapted for the DFR(Document Filing and Retrieval) is shown. In addition, a configuration model for interworking between the DFR and the multi directory, an association mechanisms between two application's operations are also described. In a distributed environment, the interworking between the DFR and a multi directory implemented by using QUIPU 8.0 of ISODE(ISO Development Environment) directory system is tested. Based on the result of this paper, an extended model ofthe directory system is proposed for providing search operation of various application' objects.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.8 no.12
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• pp.79-87
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• 1985

Environmental approach places the focus on a cause-and-effect relationship between the external environments and the internal business conditions. But that approach is an attempt to describe the characteristics of environmental constraints. W.J. Abernathy, K.B. Clark, and A.M. Kantrow attribute the Japanese carmaker's success to superiority in the manufacturing plant, especially in their process systems and work force management. They provide a paradigm for discussions of manufacturing competitiveness comparison. The structure of the paradigm has two main distinctions. The first is the division between analysis and prescription of a macro sort and those of a micro sort, the second is the division between analysis and prescription based on hardware and those based on software.

• Journal of the Korean association of regional geographers
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• v.12 no.6
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• pp.693-703
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• 2006

Keeping the balance between exploration of new possibilities and exploitation of existing certainties in organizational innovation is getting its significance as business environments become more turbulent This paper focused on the relationship between two different types of innovation and network configuration. For this purpose, we conducted the empirical studies of 168 IT SMEs located in Gyeongbuk. For this analysis, we defined two innovation types as exploratory innovation and exploitative innovation. Also, we considered network scope and strength of tie as network configuration. The results showed that the exploratory innovation had sparse network of network scope and weak tie of strength. On the contrary the exploitative innovation had dense network and strong tie.

• The Journal of Industrial Distribution & Business
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• v.8 no.5
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• pp.15-21
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• 2017

Purpose - This research aims to examine the effects of 3D online products presentation by comparing it with general presentation. Research design, data, and methodology - To rigorously investigate the differences of effects between 3D presentation and general presentation, this study examines the differences of the two presentations in vividness, informedness, entertainment, product trust, and purchase intention. This research designed two different forms of online product presentations, 3D and general presentation for an experiment. Results - The research findings indicate that 1) the vividness of online product presentation has a positive impact on the informedness and entertainment. While both vividness and informedness product presentation have a positive impact on product trust, the entertainment of online product presentation has no significant impact. 2) Vividness, informedness, entertainment, product trust, and purchasing intention showed significant differences between 3D and general product presentations. 3) Overall, 3D product presentation showed a stronger impact on purchasing intention than the general product presentation. Conclusions - This research expands the area of business presentation by comparing the differences of 3D and general presentation methods. This study made a great contribution to theory development, and also to guidelines for practice. These insights could be used by organizations in developing realistic environments for business presentations.

• 한국해양학회지
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• v.21 no.4
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• pp.211-228
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• 1986

Variations of dissolved oxygen were studied for two years in two brackish lakes, Etang de Berre and Etang de Vaine related to the north-west Mediteranean Sea. The variations also were studied at the same time in nearby seawater, and in the four main tributaries of Etang de Berre. The distributions of dissolved oxygen values and their spatio-temporal variations were well matched with the characteristics of the water masses in different environments. The concentration of dissolved oxygen and the rate of oxygen saturation in seawater (Carry-le-Rouet) ranged from 5.0 to 6.0 ml.1$\^$-1/, and from 95 to 105%, respectively. The amount of dissolved oxygen in Etang de Berre oscillated between 0.17 and 11.43 ml.1$\^$-1/ with an average of 7.40ml1$\^$-1/.The rate of oxygen saturation oscillated between 2.9 and 168.3%. Annual values of the four tributaries are as follows (ml.1$\^$-1/ and %): Durance:8.68 and 113.6;Arc : 6.87 and 95.3;Touloubre: 6.87 and 91.0;Durancole;6.36 and 96.8 The data for the evolutions of dissolved oxygen in Etang de Berre on the period between 1965 and 1978 are presented. A rather good negative correlation links oxygen with temperatures.

• Journal of Mechanical Science and Technology
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• v.19 no.6
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• pp.1290-1303
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• 2005

In this research, a remote control system has been developed and implemented, which combines autonomous obstacle avoidance in real-time with force-reflective tele-operation. A tele-operated mobile robot is controlled by a local two-degrees-of-freedom force-reflective joystick that a human operator holds while he is monitoring the screen. In the system, the force-reflective joystick transforms the relation between a mobile robot and the environment to the operator as a virtual force which is generated in the form of a new collision vector and reflected to the operator. This reflected force makes the tele-operation of a mobile robot safe from collision in an uncertain and obstacle-cluttered remote environment. A mobile robot controlled by a local operator usually takes pictures of remote environments and sends the images back to the operator over the Internet. Because of limitations of communication bandwidth and the narrow view-angles of the camera, the operator cannot observe shadow regions and curved spaces frequently. To overcome this problem, a new form of virtual force is generated along the collision vector according to both distance and approaching velocity between an obstacle and the mobile robot, which is obtained from ultrasonic sensors. This virtual force is transferred back to the two-degrees-of-freedom master joystick over the Internet to enable a human operator to feel the geometrical relation between the mobile robot and the obstacle. It is demonstrated by experiments that this haptic reflection improves the performance of a tele-operated mobile robot significantly.