• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.12 no.1
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• pp.275-281
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• 2012

Community network is a communication environment where heterogeneous devices can access and communicate with each other at any time and at any space to share information. To do so, mobile devices are required to be self-configured even in absence of communication infrastructures. Semi-infrastructured wireless ad-hoc network is a promising solution to meet with such a requirement. This paper proposes the VTC(virtual topology coordinator) system as an evaluation tool for examining network protocols that are intended to be deployed in the semi-infrastructured ad-hoc networks. VTC emulates multi-hops wireless network topology virtually using a mechanism of selective receiving MAC frame in a small area, where only a single hop communication is available. VTC system cannot consider all properties introduced in real wireless network, but do more wireless properties than verification through simulation.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.20 no.2
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• pp.375-384
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• 2016

In this paper, when stereo image, satellite view and corresponding depth maps were used as the input data, we propose a new method that convert these data to data format suitable for compressing, and then by using these format, intermediate view is synthesized. In the transmitter depth maps are merged to a global depth map and satellite view are converted to residual image corresponding hole region as out of frame area and occlusion region. And these images subsampled to reduce a mount of data and stereo image of main view are encoded by HEVC codec and transmitted. In the receiver intermediate views between stereo image and between stereo image and bit-rate are synthesized using decoded global depth map, residual images and stereo image. Through experiments, we confirm good quality of intermediate views synthesized by proposed format subjectively and objectively in comparison to intermediate views synthesized by MVD format versus total bit-rate.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.28 no.3C
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• pp.224-231
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• 2003

In this paper we proposed system parameter values of ultra-wideband Impulse Radio systems for the frequency band(3.1~10.6GHz), which is allocated by Federal Communications Commission(FCC). We also analyzed performance of the proposed system in the multiple access interference environment. According to result, application of possible pulse duration($t_{n}$) is very limited by 0.04~0.0326 ns in permission frequency range that establish in FCC. In the case of the same pulse signal power, we could know that system performance was changed by pulse repetition number($N_{s}$ ) regardless of pulse duration. Thus, We could know that we have to need duration of monocycle pulse and setting of frame un it time(Τ$_{f}$ ) according to multi user numbers and design proper pulse repetition number by transfer rate in multiple access systems design. In the IR system that needs high speed transmission more than 50 Mbps in multiple access interference environment, we could know that very serious performance decrease by multiple access interference happens. Therefore, as the design of high speed multiple access IR system, it should be designed to additional improvement techniques that can remove multiple access interference at the same time.

• Korean Journal of Biological Psychiatry
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• v.27 no.1
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• pp.9-17
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• 2020

Objectives The purpose of this study is to investigate the interest level, perception and attitude of suicide high-risk group toward the media's suicide report, and also to provide the fundamental data in order to strengthen both the standard and the recommendation of media coverage in Korea. Methods We analyzed the data from the 2013 The Korea National Suicide Survey. The study included 1500 participants aged between 19 and 75 years. The participants were selected through the regional multi-layer stratification method using the sampling frame of the 2010 Census. One-on-one face-to-face interviews investigated the interest level, opinions, and attitudes toward suicide reports and collected data on past suicide history and demographic data. The collected data were evaluated using multiple logistic regression analysis. A probability level of p < 0.05 was considered statistically significant. Results The suicide high risk groups with histories of suicidal ideations or attempts showed more interest in suicidal reports [suicidal thought odds ratio (OR) = 1.81, 95% confidence interval (CI) = 1.40-2.34 ; suicidal attempt OR = 3.21, 95% Cl = 1.52-6.78]. However, there was no difference among the groups in thought that suicide reports incite suicide (suicidal thought OR = 1.26, 95% Cl = 0.92-1.73 ; suicidal attempt OR = 0.96, 95% Cl = 0.44-2.09). The suicide high risk groups showed a positive attitude toward suicide reports, but it was not statistically significant (suicidal thought OR = 1.10, 95% Cl = 0.41-2.92 ; suicidal attempt OR = 1.10, 95% Cl = 0.76-1.59). Conclusions We suggest the need of careful attitude of media suicidal reports not to bring about copycat suicides. and also we offer suicide prevention campaign based on media leverage.

• Journal of the Korean Society of Costume
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• v.43
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• pp.125-142
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• 1999

This research was aimed to present a model of clothing products evaluation nd to classify the effect of extrinsic cues on clothing products evaluation. In order to accomplish following subjects were established. First it is to find the effect of extrinsic cues -price brand store - on perceived quality perceived risk perceived value and purchase intention of clothing products. Second it is to formulate a model of clothing products evaluation and find the relation among the variables such as extrinsic cues perceived quality perceived risk perceived value and purchase intention. This research was mainly divided into theoretical and empirical part. In the theoretical part previous theories and studies on clothing products cues clothing products evaluation perceived quality perceived risk and perceived value were examined to establish a research model and to present a theoretical frame for clothing products evaluation. In the empirical research a questionnaire was developed and statistical data were collected from during July 1997. The subjects were 862 women in the age of 20-35 living in Seoul and kyungki region. SAS and LISREL were used to analyze the collected data. frequency percentage factor analysis ANOVA duncan test correlation analysis regression analysis and LISREL were applied. The results of this research are as follows: First perceived quality consists of performance quality external quality and utility quality in a form of multi dimensional structural. Perceived risk is structured by social/resultant risk financial/fashionable risk and performance/management risk. Second this research proved that extrinsic cues are influenced by each individual variable and extrinsic cues interact with each other through the variable. The perceived quality is influenced most by price Among the perceived risk social/resultant risk by brand financial/fashionable risk by price and performance/management risk by store. respectively. Perceived value is inflenced by price and brand. Third in evaluating process consumer use extrinsic cues to first formulate perceived quality and perceived risk of clothing products and then formulate perceived value ot decide on purchase intention.

• Smart Structures and Systems
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• v.17 no.6
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• pp.957-980
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• 2016

Structural damage detection (SDD) is a challenging task in the field of structural health monitoring (SHM). As an exploring attempt to the SDD problem, a hybrid self-adaptive Firefly-Nelder-Mead (SA-FNM) algorithm is proposed for the SDD problem in this study. First of all, the basic principle of firefly algorithm (FA) is introduced. The Nelder-Mead (NM) algorithm is incorporated into FA for improving the local searching ability. A new strategy for exchanging the information in the firefly group is introduced into the SA-FNM for reducing the computation cost. A random walk strategy for the best firefly and a self-adaptive control strategy of three key parameters, such as light absorption, randomization parameter and critical distance, are proposed for preferably balancing the exploitation and exploration ability of the SA-FNM. The computing performance of the SA-FNM is evaluated and compared with the basic FA by three benchmark functions. Secondly, the SDD problem is mathematically converted into a constrained optimization problem, which is then hopefully solved by the SA-FNM algorithm. A multi-step method is proposed for finding the minimum fitness with a big probability. In order to assess the accuracy and the feasibility of the proposed method, a two-storey rigid frame structure without considering the finite element model (FEM) error and a steel beam with considering the model error are taken examples for numerical simulations. Finally, a series of experimental studies on damage detection of a steel beam with four damage patterns are performed in laboratory. The illustrated results show that the proposed method can accurately identify the structural damage. Some valuable conclusions are made and related issues are discussed as well.

• Journal of IKEEE
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• v.16 no.2
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• pp.138-144
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• 2012

In this paper, a semi-analytical approach is proposed for DSF(Decode and Selective Forward)-Relay MC-CDMA(MultiCarrier-Code Division Multiple Access) systems over multipath Rayleigh fading channels. Considering BER(bit error rate) performance and complexity, the MMSE-C(Minimum Mean squared Error-per subCarrier) is used as the combining method for MC-CDMA systems. At first, the analytical method based on error-events at relay nodes for DSF-Relay schemes is utilized in order to derive the averaged BER. Then, the averaged BER is expressed as the form considering possible all error-events. Also, proposed semi-analytical expressions have been verified by comparing with simulation results. Finally, it is verified that the derived analytical expressions can be a frame work to cover different multipath Rayleigh fading channel conditions and to measure the upper performance for DSF-Relay MC-CDMA systems.

• Research in Community and Public Health Nursing
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• v.12 no.3
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• pp.705-715
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• 2001

This study examined 19 papers published from 1977 to 2000 based on the objective frame evaluation. This purpose of this study was to examine the trend of Hwabyung research and to serve as a guide for the future 'Hwabyung' study. The results of studies were as follow. In the design of research, clinical studies are definitely dominant. As for the fields of research, the concept of Hwabyung was studied more frequently than the others. As for the authorship. psychiatrists prevailed but nursing professionals are on the increase. Research subject in clinical and survey study, patient was definitely dominant and the place of study was almost always a hospital (75%), data collection was higher on interview (58.3%). Hwabyung was considered unique culture bounded syndrome related to Korean culture. Frequent etiologic factor of Hwabyung were a husband's extra-marital affair, conflicts between houses wives and mothers-in-laws, and financial loss and suffering. From the incidence of Hwabyung, a greater number of patients with Hwabyung were middle aged women in the low economic and educational classes, and these were connected with the culture and the family system. The symptoms of Hwabyung included psychological and physical symptom, neurological disorder and disease behavior. Defense mechanisms and coping strategies for Hwabyung were somatization, suppression, orality, withdrawal, isolation, regression, help-seeking, complaining, and wreaking anger. Treatment of Hwabyung were medication, effort by herself, communication with families, consultation with psychologist, acupuncture, negative therapy, moxa, and Qi-kong. Psychiatric therapy, behavior therapy, nursing intervention on multi-interdisciplinary approach and psychiatric nursing approach were recommended for the nursing care of a Hwabyung patient.

• Journal of Ocean Engineering and Technology
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• v.19 no.5 s.66
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• pp.16-25
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• 2005

The effect of vertical riser support system on the dynamic behaviour of a classical spar platform is investigated. Spar platform generally uses buoyancy-can riser support system, but as water depth gets deeper the alternative riser support system is required due to safety and cost issues. The alternative riser support system is to hang risers off the spar platform using pneumatic cylinders rather than the buoyancy-can. The existing numerical model for hull/mooring/riser coupled dynamics analysis treats riser as an elastic rod truncated at the keel (truncated riser model), thus, in this model, the effect of riser support system can not be modeled correctly. Due to this reason, the truncated riser model tends to overestimate the spar pitch and heave motion. To evaluate more realistic global spar motion, mechanical coupling among risers, guide frames and support cylinders inside of spar moon-pool should be modeled. In the newly developed model, the risers are extended through the moon-pool by using nonlinear finite element methods with realistic boundary condition at multiple guide frames. In the simulation, the vertical tension from pneumatic cylinders is modeled by using ideal-gas equation and the vertical tension from buoyancy-cans is modeled as constant top tension. The different dynamic characteristics between buoyancy-can riser support system and pneumatic riser support system are extensively studied. The alternative riser support system tends to increase spar heave motion and needs damper system to reduce the spar heave motion.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• v.1
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• pp.141-144
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• 2006

The deviations in the injection orbital parameters, resulting from launcher dispersions, need to be estimated and used for autonomous satellite operations. For the proposed small satellite mission of the university there will be two GPS receivers onboard the satellite to provide the instantaneous orbital state to the onboard data handling system. In order to meet the power requirements, the satellite will be sun-tracking whenever there is no imaging operation. For imaging activities, the satellite will be maneuvered to nadir-pointing mode. Due to such different modes of orientation the geometry for the GPS receivers will not be favorable at all times and there will be instances of poor geometry resulting in no output from the GPS receivers. Onboard the satellite, the orbital information should be continuously available for autonomous switching on/off of various subsystems. The paper presents the strategies to make use of small arcs of data from GPS receivers to compute the mean orbital parameters and use the updated orbital parameters to calculate the position and velocity whenever the same is not available from GPS receiver. Thus the navigation message from the GPS receiver, namely the position vector in Earth-Centered-Earth-Fixed (ECEF) frame, is used as measurements. As for estimation, two techniques - (1) batch least squares method, and (2) Kalman Filter method are used for orbit estimation (in real time). The performance of the onboard orbit estimation has been assessed based on hardware based multi-channel GPS Signal simulator. The results indicate good converge even with short arcs of data as the GPS navigation data are generally very accurate and the data rate is also fast (typically 1Hz).