• Korean Security Journal
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• no.54
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• pp.57-75
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• 2018

The purpose of this study is to provide basic data to improve the working environment of industrial security workers by analyzing the effects of organizational fairness of workers in industrial security work on silence in workplace and will to adhere to security policy. The data used in this study consisted of a total of 190 respondents. Statistical analysis of correlation and multiple regression analysis was performed using the SPSS 18.0 statistical program, The results of the study are as follows. First, it can be seen that the more silent the workers in the industrial security work are not being treated fairly, the higher the silence in the workplace. Second, the factors of distribution and interaction fairness affect the will to comply with the security policy, so fair distribution and fair treatment of the compensation can increase the willingness of the industrial security worker to adhere to the security policy. Third, it was found that the dominant silent factor influenced the will to adhere to the security policy, and the more the silence about the organization and its job, the lower the will to adhere to the security policy. The results of this study show that organizational fairness and silence in the workplace directly and indirectly influence the willingness to adhere to the security policy.

• The Journal of the Korean dental association
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• v.48 no.4
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• pp.280-287
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• 2010

Objective: In spite of increasing dental treatment for the disabled, there was a few collected data on dental treatment status and dentists' perception in Korea. The purpose of this' study is to research the current dental treatment status for the disabled in Korea and to suggest public health policies for the disabled. Material and methods: Total of 68 dentists who have treated the disabled regularly were asked to fill questionnaires regarding dental treatments for the disabled. Results: 1. It is necessary to set up public dental center for the disabled in rural area. 2. In case of dental treatments relating to cerebral palsy, ADHD, autism, the compensation for treatment time and extra investment is needed. 3. Only 39.7% of dentists charged treatment fees to the disabled as same as normal patients. Moreover 38.2% of dentists answered that they didn't charge treatment fees at all when their patient are disabled. 4.23.5% of dentists provided all of dental treatments including dental implant and orthodontic appliances in Korea. However, 54.3% of dentists reported the improvement of access to dental implant, orthodontic and esthetic treatment is needed. 5. It is imperative for the government to improve the support system for the disabled. Conclusions: Through this research only 26.5% of dentists answered that they had received the fund from the government and 11.1% of them were satisfied with the support for the disabled in Korea. This indicated the improvement of government financial support system for the disabled is needed.

• The Journal of the Acoustical Society of Korea
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• v.38 no.6
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• pp.637-650
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• 2019

This paper analyzes the limitations of binaural sound that is reproduced with headphones based on Ambisonics for Virtual Reality (VR) audio. VR audio can be provided with binaural sound that compensates head rotation of a listener. Ambisonics is widely used for recording and reproducing ambient sound fields around a listener in VR audio, and the First order Ambisonics (FOA) is still being used for VR audio because of its simplicity. However, the maximum frequencies with this order is too low to perfectly reproduce ear signals, and thus the binaural reproduction has inherent limitations in terms of spectrum and sound localization. This paper investigates these limitations by comparing the signals arrived at ear positions in the reference field and the reproduced field. An incidence wave is defined as a reference field, and reproduced over virtual loudspeakers. Frequency responses, inter-aural level differences, and inter-aural phase differences are compared. The results show, above the maximum cut off frequency in general, that the reproduced levels decrease, and the horizontal localization can be provided only around the forward direction.

• Proceedings of the KOR-BRONCHOESO Conference
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• 1977.06a
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• pp.5.2-5
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• 1977

Many persons, both children and adults, suffer from impaired hearing. The handicaps that arise from this are economic, educational and above all, social. These persons need help, both medical and educational. In order to plan facilities for the medical treat ment, the rehabilitation, and the special education required by those with impaired hearing, we must know how many persons with hearing problems there are and the severity of their handicaps. The first step in knowing these is to devide hearing impairent into categories of handicap. Historically, since Beasley (1940) proposed progressive stages of deafness in terms of social disability, there was no well organized classification. of hearing handicap except related material from Huzing (1959) and Silverman (1960). In 1965, Goodman advocated a guide hearing threshold levels and degres of relating hearing impairment. During recent one year, on the bases of Goodman classification of hearing impairment and the report from Illinois Comission on children (1968), we have studied about hearing handicaps and speech life for the 180 cases, who visited to our otolaryngology department with hearing impairment. Now, we report the results of study with the referred references.

• Polymer(Korea)
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• v.36 no.4
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• pp.486-493
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• 2012

Photocurable sulfonated polyimide (SPI) polyelectrolyte containing chalcone group was prepared and fabricated on an alumina electrode pretreated with chalcone-containing silane-coupling agent. SPI films with bis(tetramethyl)ammonium 2,2'-benzidinedisulfonate ($Me_4N$-BDS)/4,4'-diaminochalcone (DAC)/pyromellitic dianhydride (PA)= 90/10/100 possessed very linear response(Y = -0.04528X+7.69446, $R^2=0.99675$) and showed resistance changing from 4.48 to $2.1k{\Omega}$ between 20 and 95 %RH. The response time for absorption and desorption measurements between 33 and 94 %RH% was about 79 s, which affirmed the high efficiency of crosslinked SPI film for rapid detection of humidity. A negative temperature coefficient showing $-0.49%RH/^{\circ}C$ was found and proper temperature compensation should be considered in future applications. Moreover, pretreatment of the substrates with chalcone-containing silane-coupling agent was performed to improve the water durability and the stability of the humidity sensors at a high humidity and a high temperature and long-term stability for 480 h. The crosslinked SPI films anchored to electrode substrate could be a promising material for the fabrication of efficient humidity sensors with superior characteristics compared to the commercially available sensors.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.21 no.7
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• pp.761-768
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• 2010

This paper presents an effective method to achieve the wideband waveform for high resolution SAR(Synthetic Aperture Radar) using the frequency multiplication technique. And also this paper analyzes the root causes for the spectral regrowth due to 3rd-order intermodulation in chirp bandwidth expansion scheme using quadrature modulator and frequency multipliers. The amplitude and phase imbalance requirement are defined based on the simulation results in terms of quadrature channel imbalance. This minimizes the degradation of range resolution, peak sidelobe ratio and integrated sidelobe ratio. The wideband chirp generator using the frequency multiplier and memory map scheme was manufactured and the compensation technique was presented to reduce the spectral regrowth of SAR waveform by minimizing the amplitude and phase imbalance. After I and Q channel imbalance adjustment, the carrier level reduces －28.7 dBm to －53.4 dBm. Chirp signal with 150 MHz bandwidth at S-band expands to 600 MHz bandwidth at X-band. The sidelobe levels are reduced by about 8 to 9 dB by compensating the amplitude balance between I and Q channels.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.28 no.10C
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• pp.995-1006
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• 2003

It is well know that in the wireless communication systems the transmitted signals can suffer from multipath fading due to the wave propagation characteristics and the obstacles over the paths, resulting in serious reduction in the power of the received signals. However, it is possible to take advantage of the inherent diversity imposed in the multipath reception if the underlying channel can be properly estimated. One of the diversity reception methods in this case is Rake processing. In this paper we study the Rake receivers for the direct-sequence spread-spectrum communication systems utilizing PN (pseudo noise) sequences to achieve spread spectrum. A conventional Rake receiver can use the finite-duration impulse (FIR) filter followed by the PN sequence demodulator, where the FIR filter coefficients are the reverse-ordered complex conjugate values of the fading channel impulse response estimates. Here, we propose a new Rake processing method by replacing the aforementioned PN code sequence with a new set of optimum demodulator coefficients. More specifically, the concept of the new optimum Rake processing is first introduced and then the optimum demodulator coefficients are theoretically derived. The performance obtained using the new optimum Rake processing is also calculated. The analytical results are verified by computer simulation. As a result, it is shown that the new optimum Rake processing method improves the MSE performance more than 10 dB over the conventional one using the fixed PN sequence demodulator. It is also shown that the new optimum Rake processing method improves the MSE performance about 10 dB over the Adaptive Correlator that performs the combining of the multipath components and PN demodulation concurrently. And finally, the MSE performance of the optimum Rake demodulator is very close to the MSE performance of OPSK demodulator under the AWGN channel.

• Clean Technology
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• v.27 no.4
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• pp.277-290
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• 2021

A supercapacitor, also called an ultracapacitor or an electrochemical capacitor, stores electrochemical energy by the adsorption/desorption of electrolytic ions or a fast and reversible redox reaction at the electrode surface, which is distinct from the chemical reaction of a battery. A supercapacitor features high specific power, high capacitance, almost infinite cyclability (~ 100,000 cycle), short charging time, good stability, low maintenance cost, and fast frequency response. Supercapacitors have been used in electronic devices to meet the requirements of rapid charging/discharging, such as for memory back-up, and uninterruptible power supply (UPS). Also, their use is being extended to transportation and large industry applications that require high power/energy density, such as for electric vehicles and power quality systems of smart grids. In power generation using intermittent power sources such as solar and wind, a supercapacitor is configured in the energy storage system together with a battery to compensate for the relatively slow charging/discharging time of the battery, to contribute to extending the lifecycle of the battery, and to improve the system power quality. This article provides a concise overview of the principles, mechanisms, and classification of energy storage of supercapacitors in accordance with the electrode materials. Also, it provides a review of the status of recent research and patent, product, and market trends in supercapacitor technology. There are many challenges to be solved to meet industrial demands such as for high voltage module technologies, high efficiency charging, safety, performance improvement, and competitive prices.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.9
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• pp.111-120
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• 2019

This study examined the mediating effects of perceived organizational support (POS) on the relationship between the person-job fit and job satisfaction of service workers. POS is divided into socioemotional POS and instrumental POS. To achieve the research purpose, a questionnaire survey was conducted on workers in charge of service jobs in domestic companies through an on-line survey system and finally, the results of 281 respondents were analyzed to verify the hypothesized research model with an 80.3% effective recovery rate. The findings are as follows. First, the person-job fit has positive effects on job satisfaction and POS. Second, among the sub-constructs of POS, socioemotional support has mediating effects, but instrumental support has no mediating effects on the relationship between person-job fit and job satisfaction. Based on the results of this study, this study suggests theoretical and practical implications for the human resource development and management of service workers. Overall, changes in the recruitment system, which can judge the person-job fit of employees who perform emotional labor facing customers, organizational culture and personnel system for establishing socioemotional support system, and compensation and workforce development system, are needed to enhance the job satisfaction of service workers.

• The Journal of the Convergence on Culture Technology
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• v.5 no.2
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• pp.23-30
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• 2019

The purpose of this study was to examine job stress, job satisfaction, and turnover intention of the nurses who work at the comprehensive nursing service units in two academic medical institutions that provide healthcare service at the tertiary care level in Korea. A descriptive study was conducted with the nurses by using self-reported questionnaires. We used descriptive statistics to summarize the data and Mann-Whitney U test for group comparison. The mean scores of job stress, job satisfaction, and turnover intention were $89.17{\pm}12.56$, $107.25{\pm}6.85$, $37.19{\pm}4.86$, respectively. Nurses with religion showed more job stress than those without. Nurses with their age below 30 years old had significantly less job satisfaction than those older than 30 years old. Monthly income was significantly associated with turnover intention in our data. The top three sub-category of the job stress were conflict with physicians, patients and their caregivers, and conflicts with others; and those of the job satisfaction were pay and promotion and task requirement. Job stress, job satisfaction, and turnover intention were significantly correlated. In order to reduce turnover intention of nursing professionals in the comprehensive nursing service, job stress related to issues on relationships with patients, their family, health care providers need to be taken into consideration. Policy and administrative support are needed to improve their work environment.