• Journal of Digital Contents Society
• /
• v.5 no.1
• /
• pp.22-27
• /
• 2004

To handle the high level radioactive materials such a spent fuel, the master-slave manipulaters (MSM) are wide1y used as a remote handling device in nuclear facilities such as the hot cell with sealed and shielded space. In this paper, the Digital Mockup which simulates the remote operation of the Advanced Conditioning Process(ACP) is developed. Also, the workspace and the motion of the slave manipulator, as well as, the remote operation task should be analyzed. The process equipment of ACP and Maintenance/Handling Device are drawn in 3D CAD model using IGRIP. Modeling device of manipulator is assigned with various mobile attributes such as a relative position, kinematics constraints, and a range of mobility. The 3D graphic simulator using the extermal input device of spare ball displays the movement of manipulator. To connect the exterral input device to the graphic simulator, the interface program of external input device with 6 DOF is deigned using the Low Level Tele-operation Interface(LLTI). The experimental result show that the developed simulation system gives much-improved human interface characteristics and shows satisfactory reponse characteristics in terms of synchronization speed. This should be useful for the development of work`s education system in the environment.

• The Korean Journal of Mycology
• /
• v.37 no.2
• /
• pp.161-166
• /
• 2009

The purpose of the present study is to develop a simple, fast and sensitive LC/MS method for simultaneous separation and the determination of an active component in the oriental medicinal mushroom Cordyceps militaris. Based on this work, the contents of cordycepin in Cordyceps militaris fruiting cultivated on various media were determined and compared. And also, the nutritional components such as minerals and vitamins were determined in order to provide useful information to consumer as a food material. The analysis methods of nutritional components were chosen on the basis of AOAC. The optimum separation for cordycepin was achieved using a solvent gradient consisting of the mixture of 0.1% formic acid in methanol (solvent B) in a background of 0.1% formic acid in water (solvent A) as a mobile phase and a 3.0${\times}$150 Waters XTera column. Selective ion monitoring (SIR) mode ([M+H]+ at m/z 252) was used for quantitative analysis of cordycepin. The cultivated Cordyceps militaris on various media contained 1~14 /g of cordycepin, 0.65~1.08% of thiamine, 0.86~7.17% of riboflavin, and 3.01~5.26% of niacin. The content of mineral components varied on categories, especially contained 500~3500% of potassium as a major mineral. Cordycepin, niacin and potassium were found much higher in the fruiting cultivated with soy power media (gold 10) than other media.

• Korean Journal of Remote Sensing
• /
• v.28 no.2
• /
• pp.245-253
• /
• 2012

The public and civilian demands regarding 3D geo-spatial information processing on mobile device including smartphone are increasing. But there are few actual implementations or application cases. This work is to present some results by a prototype implementation of 3D terrain information visualization function with satellite image and DEM using HTML5 WebGL, which is a web-based graphic library under the standardization process. This is a useful standard for cross-platform operation for 3D graphic rendering without other plug-in modules. As the results, in the different types of operating system or browser in a personal computer or a smartphone, it shows same rendering results, as long as they support HTML5 WebGL. As well;geo-metadata search and identification functions for data sets for 3D terrain visualization process are added in this implementation for the practical aspect.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.31 no.3A
• /
• pp.221-231
• /
• 2006

TCP is needed as a transport protocol to provide reliable end-to-end message delivery for MANETs in order to achieve a smooth integration with the fixed Internet. Particularly, TCP has its variants, namely TCP-Reno and TCP-Vegas. However, there has been no research work on extensive performance comparison of TCP-Reno and TCP-Vegas over AODV and OLSR. This paper is the first trial to perform the research by using ns-2 simulator. Through the extensive simulations, we found that which to select among routing protocols is more important than which to select among TCP variants, because the performance difference between TCP-Reno and TCP-Vegas over uy selected routing protocol is not so much outstanding. Particularly, TCP-Vegas relies on an accurate BaseRTT estimation in order to decide the sending rate of a TCP Sender. However, it cannot be directly applied to MANET because a route change makes the Base an used over a Previous Path obsolete. Therefore, we propose a technique for improving the performance of TCP-Vegas by considering the route change, and show the performance improvement through simulation study.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2007.06a
• /
• pp.20-20
• /
• 2007

Nanowire-based field-effect transistors (FETs) decorated with nanoparticles have been greatly paid attention as nonvolatile memory devices of next generation due to their excellent transportation ability of charge carriers in the channel and outstanding capability of charge trapping in the floating gate. In this work, top-gate single ZnO nanowire-based FETs with and without Au nanoparticles were fabricated and their memory effects were characterized. Using thermal evaporation and rapid thermal annealing processes, Au nanoparticles were formed on an $Al_2O_3$ layer which was semi cylindrically coated on a single ZnO nanowire. The family of $I_{DS}-V_{GS}$ curves for the double sweep of the gate voltage at $V_{DS}$ = 1 V was obtained. The device decorated with nanoparticles shows giant hysterisis loops with ${\Delta}V_{th}$ = 2 V, indicating a significant charge storage effect. Note that the hysterisis loops are clockwise which result from the tunneling of the charge carriers from the nanowire into the nanoparticles. On the other hand, the device without nanoparticles shows a negligible countclockwise hysterisis loop which reveals that the influence of oxide trap charges or mobile ions is negligible. Therefore, the charge storage effect mainly comes from the nanoparticles decorated on the nanowire, which obviously demonstrates that the top-gate single ZnO nanowire-based FETs decorated with Au nanoparticles are the good candidate for the application in the nonvolatile memory devices of next generation.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.12 no.2
• /
• pp.254-259
• /
• 2008

Mesh WLANs, which consist of wireless mesh routers connecting each other in a mesh topology and self-operate after their autoconfiguration, have several advantages in convenience, swiftness and flexibility of deployment and operation over existing WLANs the expansions of which are done by connecting the APs with wires. However, many technical issues still remain to be solved. Among them, network performance degradations due to the interference between the adjacent hops in multi-hop mesh WLANs, and the reusability of the existing wireless network protocols are critical problems to be answered. This work evaluates the VoIP support performance of IEEE 802.11a/g-based mesh WLANs with multiple wireless interfaces with simulations. The results show that there exit an unfairness in VoIP packet delay performances among mobile routers located at different hops, and that although the capacity of the admitted calls can be increased by increasing the size of voice packet payload it is far less than the expected one. This suggests that the existing 802.11 MAC protocols have their limitation when applied in mesh networks and their enhancement or even a newer one nay be required.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2009.05a
• /
• pp.631-634
• /
• 2009

Recent advances in wireless communication, electronics, MEMS device, sensor and battery technology have made it possible to manufacture low-cost, low-power, multi-function tiny sensor nodes. A large number of tiny sensor nodes form sensor network through wireless communication. Sensor networks represent a significant improvement over traditional sensors, research on Zigbee wireless image transmission has been a topic in industrial and scientific fields. In this paper, we design a Zigbee wireless image sensor node and multimedia monitoring server system. It consists of embedded processor, memory, CMOS image sensor, image acquisition and processing unit, Zigbee RF module, power supply unit and remote monitoring server system. In the future, we will further improve our Zigbee wireless image sensor node and monitoring server system. Besides, energy-efficient Zigbee wireless image transmission protocol and interworking with mobile network will be our work focus.

• Journal of the Korea Convergence Society
• /
• v.12 no.10
• /
• pp.235-248
• /
• 2021

The ultimate aim of this work is to explore the antecedents that affect the loneliness felt by users who actively communicate through smartphones apps. To do this, three characteristics including individual, relational, and communication characteristics that can affect loneliness and the effects of these characteristics on loneliness are empirically analyzed. The research results are as follows. First, we found that conflict resolution ability had a significant effect on interpersonal conflict and loneliness. Second, social stress was found to have a significant effect on interpersonal conflict, communication fatigue, and loneliness. Third, lack of communication was found to have a significant effect on conflict resolution ability and loneliness. Finally, we found that communication fatigue had a significant effect on loneliness. These results are interpreted that in order to reduce the loneliness, it is necessary to continuously improve the ability to wisely resolve conflicts that may arise in the relationship between oneself and others. In addition, it is necessary to reduce the fear or burden of building relationships with others.

• Journal of Korea Trade
• /
• v.23 no.6
• /
• pp.1-13
• /
• 2019

Purpose - This study deals with a strategic plan for meeting the value added criteria effectively, which is one of the methods of determining origin used in preferential trade such as FTA. Automobile products, one of the major Korean export items, were selected to give a practical use against the FTA requirements. Design/methodology - This study is based on the value-added criteria of the Korea-US and Korea-EU FTAs that apply various value-added criteria. The Korea-US FTA adopts the RVC method based on the integration, deduction and net cost methods, while the MC method is employed in the Korea-EU FTA. The methodology used in this work is an extended literature review, analysis of the value-added criteria applied to automobile products under Korea-US and Korea-EU FTA with some secondary statistics. Findings - Based on in - depth analysis of the value - added criteria requirements for automobile products stipulated in the Korea - US FTA and the Korea - EU FTA, two strategic considerations are suggested. First is 'appropriate value-added strategy' and the second is 'strategy of changing production and trade structure'. The second strategy is a bit used in Korea but this is not considered best if the first strategy is ignored or forgotten. The second one is meaningful when this becomes inevitable. Research limitations/implications - This study is primarily designed to assist Korean auto mobile industry players exporting to EU and USA but this may help to auto part or material producers in FTA counter party territories being EU or USA as the preferential tariffs are applied on a inter region basis. A further research other than auto mobiles using other major FTAs might be followed later. Originality/value - There has been so far little research on strategic factors to meet the value-added origin requirements. This study, therefore, is expected to contribute facilitating the decision of FTA origin and to improve the utilization of FTA by allowing exporting companies using value added criterion to more smoothly meet origin requirements. This will also enable the tax authorities to utilize the value-added criterion to validate effectively the origin of imports where preferential tariffs are applied.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• v.15 no.2
• /
• pp.800-813
• /
• 2021

With the advent of 5G communications, internet of vehicles technology has been widely used in vehicles. Then the dynamic spread of information between vehicles began to come into focus with more research. It is well known that the identification of nodes with great spread influence has always been a hot topic in the field of information spreading. Most of the existing work measures the propagation influence by degree centrality, betweenness centrality and closeness centrality. In this paper, we will identify influential vehicle nodes based on the mobility characteristics of vehicles to explore the information spreading between vehicles in VANETs. Different from the above methods, we mainly explore the influence of the radius of gyration and vehicle kilometers of travel on information spreading. We use a real vehicle trajectory data to simulate the information transmission process between vehicles based on the susceptible-infected-recovered SIR model. The experimental results show that the influence of information spreading does not enhance with increasing radius of gyration and vehicle kilometers of travel. The fact is that both the radius of gyration and the distance travelled have a significant influence on information spreading when they are close to the median. When the value of both is large or small, it has little influence on information spreading. In view of this results, we can use the radius of gyration and vehicle kilometers of travel to better facilitate the transmission of information between vehicles.