• Korean Security Journal
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• no.31
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• pp.125-155
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• 2012

Terrorist organization has shown the trend of secret organization and it is harder to cope with terrorism because of uncertainty of terrorism. Homegrown terrorism is the one, whose preparation, execution and effect are restricted to domestic area. By the way, in the worldwide economic depression, violence and radical demonstration have shown the expansion trends as in Middle East, political revolution of Africa, anti-social resistance of Europe and Wall Street Occupation of USA. Homegrown terrorism is occurring in various countries such as UK and Spain as well as USA. Specialists warn homegrown terrorism in Korea. The purpose of this study was to prospect the possibility of homegrown terrorism that can be generated in the transfer to multi-culture society as various foreigners come to Korea rapidly and suggest the method to cope with the trend. The study analyzed environment and analysis of homegrown terrorism that Korea faces now. The methods to cope with homegrown terrorism are as follows. First, distribution of radical homegrown terrorism via internet should be prevented. Second, the connection between terrorist organization and homegrown terrorist should be prevented. Third, there should be a cooperation among government, residents and religious group. Fourth, there should be an open approach against multi-culture society. Fifth, there should be a systematic control for cause of new conflict. Finally, there should be a long-term approach to cause of new conflict. If we do not make an effort to prevent homegrown terrorism, terrorism environment may face new aspect and national and social cost for it will increase.

• Journal of Internet Computing and Services
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• v.17 no.6
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• pp.17-23
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• 2016

In the future network such as Internet of Things (IoT), the number of computing devices are expected to grow exponentially, and each of the things communicates with the others and acquires information by itself. Due to the growing interest in IoT applications, the broadcasting in Opportunistic ad-hoc networks such as Machine-to-Machine (M2M) is very important transmission strategy which allows fast data dissemination. In distributed networks for IoT, the energy efficiency of the nodes is a key factor in the network performance. In this paper, we propose a fuzzy logic based probabilistic multi-hop broadcast (FPMCAST) algorithm which statistically disseminates data accordingly to the remaining energy rate, the replication density rate of sending node, and the distance rate between sending and receiving nodes. In proposed FPMCAST, the inference engine is based the fuzzy rule base which is consists of 27 if-then rules. It maps input and output parameters to membership functions of input and output. The output of fuzzy system defines the fuzzy sets for rebroadcasting probability, and defuzzification is used to extract a numeric result from the fuzzy set. Here Center of Gravity (COG) method is used to defuzzify the fuzzy set. Then, the performance of FPMCAST is evaluated through a simulation study. From the simulation, we demonstrate that the proposed FPMCAST algorithm significantly outperforms flooding and gossiping algorithms. Specially, the FPMCAST algorithm has longer network lifetime because the residual energy of each node consumes evenly.

• Proceedings of the Materials Research Society of Korea Conference
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• 2011.05a
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• pp.8.1-8.1
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• 2011

Nanocrystalline titanium dioxide ($TiO_2$) materials have been widely used as an electron collector in DSSC. This is required to have an extremely high porosity and surface area such that the dye can be sufficiently adsorbed and be electronically interconnected, resulting in the generation of a high photocurrent within cells. In particular, their geometrical structures and crystalline phase have been extensively investigated as important issues in improving its photovoltaic efficiency. In this study, we present a new strategy to fabricate a photoelectrode having a periodic structured $TiO_2$ film templated from 1D or 3D polystyrene (PS) microspheres array. Monodisperse PS spheres of various radiuses were used for colloidal array on FTO glasses and two types of photoelectrode structures with different $TiO_2$ materials were investigated respectively. One is the igloo-shaped electrode prepared by $TiO_2$ deposition by RF-sputtering onto 2D microsphere-templated substrates. At the interface between the film and substrate, there are voids formed by the decomposition of PS microspheres during the calcination step. These holes might be expected to play the predominant roles as scattering spherical voids to promote a light harvesting effect, a spacious structure for electrolytes with higher viscosity and effective paths for electron transfer. Additionally the nanocrystalline $TiO_2$ phase prepared by the RF-sputtering method was previously reported to improve the electron drift mobility within $TiO_2$ electrodes. This yields solar cells with a cell efficiency of 2.45% or more at AM 1.5 illumination, which is a very remarkable result, considering its $TiO_2$ electrode thickness (<2 ${\mu}m$). This study can be expanded to obtain higher cell efficiency by higher dye loading through the increase of surface area or multi-layered stacking. The other is the inverse opal photonic crystal electrode prepared by titania particles infusion within 3D colloidal arrays. To obtain the enlargement of ordered area and high quality of crystallinity, the synthesis of titania particles coated with a organic thin layer were applied instead of sol-gel process using the $TiO_2$ precursors. They were dispersed so well in most solvents without aggregates and infused successfully within colloidal array structures. This ordered mesoporous structure provides the large surface area leading to the enough adsorption of dye molecules and have an light harvesting effect due to the photonic band gap properties (back-and-forth reflection effects within structures). A major advantage of this colloidal array template method is that the pore size and its distribution within $TiO_2$ photoelectrodes are determined by those of latex beads, which can be controlled easily. These materials may have promising potentials for future applications of membrane, sensor and so on as well as solar cells.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.23 no.6
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• pp.740-747
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• 2012

An Active Electronically Scanned Array(AESA) radar required necessarily as the Fire Control Radar(FCR) of recent fighters has ununiform detection range with regard to scan angle due to scan loss. Although the compensation method of scan loss in an AESA radar with variable dwell time is investigated, the effectiveness of the method in a fighter FCR with multi-function such as search, track, and missile guidance within limited resources should be considered systematically. In this paper, uniform search performance of an AESA radar using variable dwell time with regard to scan angle is derived. We assumed the search load of 50 % for case without changing dwell time in fixed frame time and showed the fighter FCR requirement for multi-function is not satisfied because the search load for the uniform search performance should be increased by about 100 %. On the other hand, in case of increasing the frame time for the uniform search performance and search load of 50 %, degradation of the search performance is shown by 86.7 % compared with the former. Based on these analyses, the effective beam operation strategy on an airborne AESA radar with uniform search performance in whole scan area is described with consideration of frame time, search load and performance as a whole.

• The Korean Journal of Archival Studies
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• no.41
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• pp.175-212
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• 2014

In 2001 a large amount of labor record have been donated from Jeontaeil Labor Archive-Institute to SungKongHoe University(SKHU). Institute of Labor History in SKHU was established in the wake of the installation of the labor archive. Development of oral archive raised the awareness of the various relationships between the use and production of labor record. Interviewees of oral testimony expressed dissatisfaction and the role of the researchers was not sufficiently exhibited. Examining the main cases of Korea union movement history, we can find contradictions between the use and production of labor record clearly. Interval of interpretation and memory was too big between the parties of 'democratic' union movement in the 1970s. While among the parties who took part in Guro Alliance Strike of 1985, there is a group that remains in the "winner" in history on the one hand, but "loser" on the other without any reasonable criterion. Active intervention of the record users(researchers) is very limited. Among citizens or workers how will be resolved such "struggle of memory" in due process can not be seen. This is one of the reasons why labor archive is not rooted in the region. In this paper, I present a methodological alternatives for the production and use of records through the construction of participatory labor archive. Further, the reconstituted contents of the "documenting locality" strategy by complementing the theoretical part of the method of participation. The study of local and locality requires a "scale" dimension that will make up the identity recognition space, a memory and identity, a social relationship rather than the dimension of the physical space. Alternative "documenting locality" strategy will be able to contribute to solve the problems that occur between the production and use of the recording in labor archive.

• The Korean Journal of Applied Statistics
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• v.28 no.6
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• pp.1047-1061
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• 2015

Stratified random sampling is a powerful sampling strategy to reduce variance of the estimators by incorporating useful auxiliary information to stratify the population. Sample allocation is the one of the important decisions in selecting a stratified random sample. There are two common methods, the proportional allocation and Neyman allocation if we could assume data collection cost for different observation units equal. Theoretically, Neyman allocation considering the size and standard deviation of each stratum, is known to be more effective than proportional allocation which incorporates only stratum size information. However, if the information on the standard deviation is inaccurate, the performance of Neyman allocation is in doubt. It has been pointed out that Neyman allocation is not suitable for multi-purpose sample survey that requires the estimation of several characteristics. In addition to sampling error, non-response error is another factor to evaluate sampling strategy that affects the statistical precision of the estimator. We propose new sample allocation methods using the available information about stratum response rates at the designing stage to improve stratified random sampling. The proposed methods are efficient when response rates differ considerably among strata. In particular, the method using population sizes and response rates improves the Neyman allocation in multi-purpose sample survey.

• Korean Chemical Engineering Research
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• v.50 no.4
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• pp.729-732
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• 2012

Herein we report the in-situ synthesis and direct decoration of chalcogenide naoparticles (NPs) onto multiwalled carbon nanotubes (MWCNTs) through an ionic liquid-assisted sonochemical method (ILASM). The as-obtained MWCNT/$BMimBF_4$/CdTe, MWCNT/$BMimBF_4$/ZnTe and MWCNT/$BMimBF_4$/ZnSe nanocomposites were characterized by TEM images and EDS spectra. In particular, the morphologies of nanocomposites such as bump-like, rough, and smooth core-shell structures were strongly influenced by the type of precursors and the interactions with MWCNT. This synthetic strategy opens a new way to directly synthesize and deposit semiconducting NPs (s-NPs) onto CNTs, which consist of binary components obtained from two precursors with different reaction rates.

• Journal of the Korea Institute of Military Science and Technology
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• v.17 no.6
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• pp.853-860
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• 2014

This paper introduces a Korean rescue robot and presents a whole body kinematic control strategy. The mission of the rescue robot is to move and lift patients or soldiers with impaired mobility in the battlefields, hospitals and hazardous environments. In order for a robot to rescue and assist humans, reliable mobility in various environments, large load carrying capacity, and dextrous manipulability are required. For these objects the robot has variable configuration mobile platform with tracks, dual arm manipulator, and two types of grippers. The electric actuators provide the strength to lift a wounded soldier up to 120 kg using whole body joints. To control the robot with multi degree of freedom, we need to synthesize complex whole-body behaviors, and to manage multiple task primitives systematically. We are to present a whole body kinematic control methodology, and demonstrate its effectiveness through numerical simulations.

• Journal of Korean Society for Atmospheric Environment
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• v.28 no.4
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• pp.384-395
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• 2012

This study was performed to develop the source profiles for fine particles ($PM_{2.5}$) emitted from the biomass burning. The multi-method research strategy included a usage of combustion devices such as field burning, fireplace, and residential wood burning to burn rice straw, fallen leaves, pine tree, and oak tree. The data were collected from multiple sources and measured water-soluble ions, elements, elemental carbon (EC), and organic carbon (OC). From this study, it turned out that OC (34~67%) and EC (1.2~39%) are the major components emitted from biomass burning. In the case of burning rice straw at field burning, OC (66.6%) was the most abundant species, followed by EC (4.3%), $Cl^-$ (3.6%), Cl (2.1%), and $SO^{2-}_4$(1.9%). Burning rice straw, fallen leaves, pine tree, and oak tree at fireplace, the amount of OC was 58.5%, 52.7%, 52.5%, and 61.2%, and that of EC was 1.2%, 18.4%, 36.5%, and 2.7%, respectively. The ratio of OC for the burning of pine tree and oak tree from the residential wood burning device was 56.9% and 34.3%, and that of EC was 25% and 38.6%, respectively. Applying the measured data with respect to the proportion of components emitted from biomass burning to reference model, it turned out that self-diagnosed result was appropriate level, and the result based on the model is in highly corresponding to actual timing of biomass burning.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.31 no.6B
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• pp.517-526
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• 2006

In order to achieve high capacity and reliable link quality in wireless communication, the significant efforts should be concentrated on mitigating interference between cells. To solve the interference problem, the newly introduced concept of a Distributed Wireless Communication System (DWCS) can provide the capability of joint control of the signals at multiple cells. This paper proposes a new concept of virtual cell: the Dual Virtual Cell (DVC), and also proposes DVC employment strategy based on DWCS network. The proposed system manages two kinds of virtual cell. One is the Active Virtual Cell which exists for user's actual data traffic and the other is the Candidate Virtual Cell which contains a set of candidate antennas to protect user's link quality from performance degradation or interruption. The proposed system constructs DVC by using antenna selection method. Also, for multi-user high-rate data transmission, the proposed system introduces multiple antenna technology to get a spatial and temporal diversity gam and exploits space-Time Trellis Codes known as STTC to increase a spectral efficiency.