• Convergence Security Journal
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• v.13 no.3
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• pp.25-31
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• 2013

Looking at the recent value change of users and the usage pattern of network users, it is changing from simple web information, one-way information acquisition and data transmission to increase of usage of multimedia, increasing demand for security and customization, and increasing demands for free mobility. Due to this change of demand, the services which were provided individually, developed into a form which is merged, the network also seems to develop into the combined network from the individual network for individual service, and the communication network control technology which is the core technology is also rapidly developing. To reflect the users' demands, the next generation network created the multi-layer network which is based on the WDM/IP transmission system and added the to make it easy to restructure. P-OTS (Packet-Optical Transport System) can be defined as a platform that combines SONET/SDH, Ethernet, DWDM, optical transport network (OTN) switching and reconfigurable optical add-drop multiplexers (ROADMs). In this paper, we suggested that the optimum path choice be performed through diversification of the PCE-based path selection using the information of various layers altogether in the multi-layer environment, compared with the established path selection method when the path was selected using the information of each layers.

• The Transactions of the Korea Information Processing Society
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• v.6 no.6
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• pp.1581-1589
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• 1999

In B-ISDN(Broadband Integrated Services Digital Networks), the efficient implementation of multicast function is very important since the demand for distributed type of service such as VOD(Video On Demand) system is expected to grow. In this paper, the multicast performance characteristics of fully-interconnected switch fabric used for our research is the proper architecture for a small-sized switch element, and it uses bit addressing method for addressing scheme and thus it is easy to implement multicast function without adding a function block. To incorporate the bursty nature of traffic in ATM networks, we used IBP(Interrupted Bernoulli Process) model as an input traffic model. We presented and analyzed the simulation results in terms of the multicast operation of the switch. Based. on this study, it its analyzed that congestion avoidance may be feasible if we use a proper traffic control scheme by finding an overload point due to multicast.

• Korean journal of food and cookery science
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• v.28 no.2
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• pp.97-110
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• 2012

The purposes of this study were to examine the levels of job stress and job burnout perceived by nutrition teachers and dietitians in school foodservice in Gyeongsangnam province and to analyze job stress factors affecting job burnout. A total of 270 questionnaires were distributed from December 10 to 29, 2010 and 252 were returned (response rate : 93.3%). A total of 245 were used in the final analysis (usage rate : 90.7%), excluding seven improper questionnaires. The results of this study were as follows : 100% of the respondents were women, and their mean age was 38. 60% were nutrition teachers and 40% were dietitians. The level of job stress and job burnout of the respondents were 2.89 points (on a 5-point Likert scale) and 3.70 (on a 7-point Likert scale), respectively. In regard to job stress factors, job demand (3.97) recorded the highest scores, followed by organizational system (2.99), lack of reward (2.85), interpersonal conflict (2.69), job insecurity (2.63), organizational climate (2.63), and insufficient job control (2.45) in that order. Exhaustion burnout (4.60) recorded the highest points among job burnout factors, followed by cynicism (3.46), and professional efficacy (3.04) in that order. Job stress factors affecting job burnout were organizational system (p<.001), job insecurity (p<.001), lack of reward (p<.001), and organizational climate (p<.01). In conclusion, it is necessary to provide human resources management strategies to lower job demand and workload in order to reduce job stress and job burnout for dietitians and nutrition teachers in school foodservice.

• Korean Journal of Environmental Agriculture
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• v.39 no.3
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• pp.214-221
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• 2020

BACKGROUND: The demand for pesticide registration has kept increasing for minor crop cultivation in greenhouse since Positive List System (PLS) has been launched. Thus, much study on the evaluation of pesticide residues in minor crops is required to examine the demand. In this study, we evaluated residues of acetamiprid, boscalid, imidacloprid and pyraclostrobin in the minor crop mustard green to provide the potential data for their registration. METHODS AND RESULTS: Pesticide granule formulations of acetamiprid, boscalid, imidacloprid and pyraclostrobin were incorporated into soil and applied onto field soil surface at rates of 3 kg/10a, 6 kg/10a, 3 kg/10a and 6 kg/10a, respectively. The pesticides were also applied at the two times higher than the rates to compare the residues between the application rates. Mustard green seeds were sown 1 day after pesticide application and cultivated under greenhouse conditions. LC/MS/MS analyses coupled with a modified QuEChERs method were employed for determination of the pesticides in plant samples. The method limits of quantitation (LOQ) of the pesticides were 0.01 mg/kg, and the matrix calibration curves of the pesticides showed linearity with coefficient values of determination (r²) greater than 0.995. The average recovery values of the pesticides fortified in control samples at rates of LOQ and 10LOQ ranged from approximately 77.5% to 101.2% with relative standard deviation values lower than 14%. The pesticides in the mustard green samples cultivated for 53 days after sown were determined to be lower than the LOQ level. CONCLUSION: Acetamiprid, boscalid, imidacloprid and pyraclostrobin were found at a level lower than 0.01 mg/kg in the minor crop mustard green. Thus, their residues in mustard green would not violate PLS under greenhouse conditions.

• Anxiety and mood
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• v.16 no.1
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• pp.24-31
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• 2020

Objective : The purpose of our study was to investigate the relationship between job stress and depressive disorder among emotional laborers in a city. Methods : A total of 677 emotional laborers living in Jeonju-city participated in this study. The participants completed survey questions regarding demographic characteristics, job stress (using the Korean Occupational Stress Scale-24, KOSS-24), and depression (the Patient Health Questionnaire-9, PHQ-9). Logistic regression was performed to estimate the association between job stress and depression. Results : Our results indicated that 34.9% of the participants had a high risk of total job stress and 21.7% of participants had depression. In the multivariate logistic regression analysis, female sex (OR=1.66, 95% CI=1.01-2.72) and total job stress (OR=3.84, 95% CI=2.57-5.75) were significantly associated with depression after adjusting for confounding factors. Among the subscales of job stress, job demand (OR=3.06, 95% CI=1.99-4.72) and occupational climate (OR=1.88, 95% CI=1.19-2.97) were significantly associated with depression. But insufficient job control, interpersonal conflict, job insecurity, the organizational system and lack of rewards were not. Conclusion : Among the emotional laborers, job stress, particularly job demand and occupational climate, were major contributing factors associated with depression. Early screening and preventive strategies focusing on job stress could reduce the impact of depression in emotional laborers.

• Korean Journal of Health Education and Promotion
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• v.24 no.2
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• pp.29-44
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• 2007

Objectives: The administrative employees of government were analyzed on their levels of fatigue symptoms to reveal the various factors related to them. Methods: The self-administered questionnaires were performed, during the period between Dec. 5th, 2005 and Jan. 31st, 2006, to 1,005 individuals in the service of general administration located in Daejeon Metropolitan City. The survey items included subjects' socio-demographic and job-related characteristics, health-related behavior, degree of job demand, job autonomy, social support in work, type A behavior pattern, locus of control, sense of self-esteem, and degree of fatigue. The study results were analyzed and the authors came to the following major findings, by univariate and multiple regression analysis with degree of fatigue dependent variables and other variables independent. Results and Conclusions: The study results indicated that the level of fatigue symptoms is so complicatedly influenced by variable factors as well as job-related characteristics such as socio-demographic characteristics, rank in work, or job career, to a greater extent, by job specifications and personality traits(type A) like whether performing health-related behavior or not, job demand, job autonomy, social support in work, or sense of self-esteem. Thus the effective strategy for stress reduction among governmental employees requires additional programs focusing on innovated job specifications and managed personality trait.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.35 no.11B
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• pp.1696-1703
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• 2010

Increased demand for military satellite communications system and due to the depletion of resources of existing satellite communications frequencies, Ka-band and EHF-band satellite communication systems is growing demand for development. As a result, the study of rain attenuation mitigation for Ka/EHF-band frequencies has been achieved. The method to compensate rain attenuation on Ka-band(20/30) using the signal power measurement function in Digital Transponder of Next Military Satellite has been proposed in this paper. This method is more effective than generally used method by Beacon and UPC(uplink power control) in giving the precise rain attenuation measurement and correction.

• Journal of Korean Society on Water Environment
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• v.33 no.5
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• pp.531-537
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• 2017

The biologic Oxygen Demand (BOD) is a reliable and generally accepted indicator of water pollution by organic pollutants. Accordingly, estimation of BOD export from paddies carries important implications fwith regard to water management in rural areas. In this study, hydrology and BOD concentration were monitored during the period 2008 through 2012, in an effort to understand the characteristics of BOD export from paddy fields. The findings demonstrated that BOD load by rainfall above 50 mm. occupied about 50 % of total load, whereas the load by less than ten mm. rainfall occupied about 29 % of the total load during periods of stormy activity. It therefore seems that it could be possible to reduce the BOD load up to 29 % during storm periods, when drainage control conducted for rainfall less than ten mm.(an amount which is relatively easy to manage). The documented mean loads of storm and non-storm were $17.1kg\;ha^{-1}\;yr^{-1}$ and $11.2kg\;ha^{-1}\;yr^{-1}$, respectively. The BOD load during the significant rainfall period was similar to the renewed unit load by NIER (2014). However, there were substantial differences between unit load and actual load when the non-storm load was incorporated into the BOD load estimation from paddy fields. In view of the foregoing, it is felt that, the non-storm load needs to be further considered and managed for the successful implementation of Total Maximum Daily Load (TMDL) program.

• Proceedings of the Korea Concrete Institute Conference
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• 2008.04a
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• pp.345-348
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• 2008

Recently, demand is caused that new building environment of value added rising demand on the lines of becoming bigger, manhattanize of structure and becoming high standard of structure in a construction site and influx of advanced foreign nation technique. To satisfy these requirements for alternative, structures applied to the PSC, PC is increasing. Double Tee Slab is possible for long length structure and applied to the method of construction. When assembling Double Tee Slab produced by the factory in the field, becamed carry-out topping concrete in upper, but occurred crack to slab line. There is no structural problem to crack occurred in upper, waterproof in maintenance and repair of structure due to a conservative cause several problems.

• The KIPS Transactions:PartA
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• v.16A no.4
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• pp.255-262
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• 2009

We present an autonomous entertainment dolphin robot system based on ubiquitous sensor networks(USN). Generally, It is impossible to apply to USN and GPS in underwater bio-mimetic robots. But An Entertainment dolphin robot which presented in this paper operates on the water not underwater. Navigation of the underwater robot in a given area is based on GPS data and the acquired position information from deployed USN motes with emphasis on user interaction. Body structures, sensors and actuators, governing microcontroller boards, and swimming and interaction features are described for a typical entertainment dolphin robot. Actions of mouth-opening, tail splash or water blow through a spout hole are typical responses of interaction when touch sensors on the body detect users' demand. Dolphin robots should turn towards people who demand to interact with them, while swimming autonomously. The functions that are relevant to human-robot interaction as well as robot movement such as path control, obstacle detection and avoidance are managed by microcontrollers on the robot for autonomy. Distance errors are calibrated periodically by the known position data of the deployed USN motes.