• Journal of Multimedia Information System
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• 제1권2호
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• pp.127-132
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• 2014

The transverse electromagnetic (TEM) cells are widely used for electromagnetic compatibility (EMC) testing and field probe calibrations. We propose the verification of TEM mode with statistical method using a four-port TEM cell. The verification results are compared with Normal, Rayleigh, and Gamma distribution. As a result, the 75 % quantile of the Rayleigh distribution is excellent agreement with the true quantiles for a number of calibration points.

• 한국지하수토양환경학회:학술대회논문집
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• 한국지하수토양환경학회 2003년도 추계학술발표회
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• pp.99-101
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• 2003

Unsaturated hydraulic conductivity models have been widely used for the numerical modeling of water flow and contaminant transport in soils. In this study, a simple hydraulic conductivity model is developed by using information of particle-size distribution from the lognormal distribution model and its results are compared with those from the Kosugi-Mualem (KM) model. The accuracy of the proposed model is verified for observed data chosen from the international UNSODA database. Results showed that the proposed model produces adequate predictions of hydraulic conductivities. Performance of this model is generally better than the KM function.

• 유통과학연구
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• 제16권2호
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• pp.53-65
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• 2018

Purpose - The purpose of this study is to investigate the effect of gamma - irradiation on the effluent from food distribution in the large agricultural and marine products market. This study will contribute to the distribution process as well as the agricultural and fishery distribution facilities. Research design, data, and methodology - In order to reduce the odor, the smell was examined in the anaerobic digestion process by irradiating gamma rays to the wastewater of mixed food discharged from a large restaurant. An odor determination panel list was constructed to determine if the odor was present in the air dilution drainage and the odor concentration was analyzed by instrumental analysis. Results - It was confirmed that the sulfur content increased gradually from 3 months. Ammonia decreased from 33.57ppm at the initial measurement to 4.12 ppm at the end of the experiment. Methane production was highest at 100kGy when exposed to gamma rays of 0-200kGy at pH 12. In other words, it is considered that gamma irradiation doses are most effective at 100kGy and are suitable for large capacity wastewater treatment facilities in terms of economic feasibility. Conclusions - In pre-treatment of compound food wastewater, gamma irradiation is most cost effective when examined at 100kGy. The economic efficiency of the pre-treatment method by gamma irradiation is much higher than the wastewater treatment in the large-scale agricultural and marine products distribution market.

• 에너지공학
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• 제23권3호
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• pp.36-41
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• 2014

The world's overall need for natural gas (NG) has been growing up fast, especially in the residential sector. The better the estimation of residential NG consumption (RNGC) distribution, the better decision-making for a residential NG policy such as pricing, demand estimation, management options and so on. Approximating the distribution of RNGC is complicated by zero observations in the sample. To deal with the zero observations by allowing a point mass at zero, a mixture model of RNGC distributions is proposed and applied. The RNGC distribution is specified as a mixture of two distributions, one with a point mass at zero and the other with full support on the positive half of the real line. The model is empirically verified for household RNGC survey data collected in Korea. The mixture model can easily capture the common bimodality feature of the RNGC distribution. In addition, when covariates were added to the model, it was found that the probability that a household has non-expenditure significantly varies with some variables. Finally, the goodness-of-fit test suggests that the data are well represented by the mixture model.

• 전자공학회논문지CI
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• 제42권6호
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• pp.29-36
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• 2005

다가올 유비쿼터스 컴퓨팅 환경에서 RFID(Radio Frequency IDentification)는 사물에 대한 인식과 차별화된 정보 제공의 수단으로 사용될 것이다. 하지만 RFID에 대한 보안서비스는 아직까지 미흡한 실정으로 이에 대한 대책 마련이 시급하다. 본 논문에서는 RFID 시스템에 대한 도청과 위조 및 변조 문제와 프라이버시 문제를 해결하기 위한 방안으로 RC5 암호 알고리즘과 Re-Distribution 프로토콜을 사용해 이에 대한 해결책을 제시하고자 한다. 먼저 Pre-Distribution 프로토콜을 사용해 RFID 시스템에서의 2가지 주체인 태그와 리더에서 사용할 비밀키를 생성하여 분배한다. 이를 토대로 가변적이고 적은 자원 사용량을 갖는 RC5 암호 알고리즘을 이용해 RFID 시스템에 요구되는 보안 서비스를 제공할 수 있다. 제안한 안전한 RFID 시스템의 성능평가를 위해 ATmega128 환경에서의 시뮬레이션 결과를 나타내었다.

• 한국물환경학회지
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• 제36권3호
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• pp.185-193
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• 2020

Bimodal flocculation describes the aggregation and breakage processes of the flocculi (or primary particles) and the flocs in the water environment. Bimodal flocculation causes bimodal size distribution with the two separate peaks of the flocculi and the flocs. Extracellular polymeric substances and ionic species common in the water environment increase the occurrence of bimodal flocculation and flocculi-floc size distribution, under the flocculation mechanisms of electrostatic attraction and polymeric bridging. This study investigated bimodal flocculation and flocculi-floc size distribution, with respect to the extracellular polymeric substance concentration and ionic strength in the kaolinite-containing suspension. The batch flocculation tests comprising 0.12 g/L of kaolinite showed that the highest flocculation potential occurred at the lowest xanthan gum (as extracellular polymeric substances) concentration, under all the ionic strengths of 0.001, 0.01, and 0.1 M NaCl. Also, it was important to note that the higher ionic strength resulted in the higher flocculation potential, at all the xanthan gum concentrations. The bimodal flocculation and flocculi-floc size distribution became apparent in the experimental conditions, which had low and intermediate flocculation potential. Besides the polymeric bridging flocculation, steric stabilization increased the flocculi mass fraction against the floc mass fraction, thereby developing the bimodal size distribution.

• 한국환경보건학회지
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• 제46권6호
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• pp.694-701
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• 2020

Objectives: The main purpose of this study is to evaluate heavy metal concentrations (Cd, As, Hg, Pb, Cr6+), particle size distribution, hydrochloric acid solubility, and parasite eggs in sand in five non-designated sandy beaches in Gyeonggi Province. Methods: The sampling sites are five non-designated Gyeonggi-do sandy beaches located in Ansan and Hwaseong. ICP-OES and UV, a Vibratory Sieve Shaker, and PCM were respectively used to analyze heavy metal concentrations, particle size distribution, and parasite eggs in the sand. Results: Heavy metals were detected within the beach's safety management standards and some of the detected As and Pb before and after beach opening were lower than one-quarter of the average value. In addition, the results of the T-test to confirm the As and Pb concentration changes before and after opening showed a significant difference in some beaches. The composition of sand was 86.53% according to the particle size distribution standard (2.0-0.02 mm), and the hydrochloric acid solubility was the highest at Gubongsolsup (4.9%) and the lowest at Bangameo-li (0.2%). Parasite eggs were undetected in all beach sand before and after opening. Conclusions: The safety of heavy metal concentrations in sandy beaches was secured in the selected five beaches in Gyeonggi Province. However, continuous efforts are required to make Gyeonggi-do's beaches suitable according to the Act on the Use and Management of Beaches.

• 유통과학연구
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• 제22권4호
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• pp.47-58
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• 2024

Purpose: Achieving organizational effectiveness is the ultimate goal that every business entity or institution targets. To achieve this, organizations need to consider various factors that have an impact on their performance. This article analyzes the distribution influence of six main elements that have a central role in shaping sustainable organizational effectiveness, which are organizational culture, job satisfaction, interpersonal communication, talent management, knowledge management, and information technology. Research Design Data and Methodology: This research uses a quantitative approach, focusing on manufacturing companies located in Surabaya as the main object, involving twenty manufacturing companies as research targets, and 10 employees in each company. The sample selection process was carried out through the application of random sampling techniques. The analysis in this research uses the multiple linear regression method and uses SPSS version 26 software. Results: Distribution of six major factors used in this research are related to each other and contribute significantly to overall organizational effectiveness. Conclusion: Organizations that can combine the distribution of a positive culture, prioritize employee satisfaction, encourage effective communication, manage talent and knowledge efficiently, and utilize information technology wisely will have greater potential to achieve their goals and survive in the intensely competitive business environment.

• 한국해안·해양공학회논문집
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• 제36권1호
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• pp.20-36
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• 2024

요 지 : 본 연구에서는 먼저 우리나라 해역별 해양환경 특성이 담긴 장기 파랑 관측자료로부터 Goda 모형을 활용하여 파력과 양력 시계열자료를 생성하였다. 이어 이렇게 생성된 시계열자료부터 Three-parameter Weibull distribution에 기반한 파력과 양력 확률모형을 개발하였다. 해역별로 다른 우리나라 해양환경은 파력과 양력 확률모형 모수에서도 그 차이를 확연하게 드러내었다. 충분히 발달한 풍성 파가 우월한 남해안의 경우 큰 Scale Coefficient, 작은 Location Coefficient, 1.3 전후의 Shape Coefficient로 특정되는 것을 확인하였다. 이에 비해 파랑의 성장이 취송거리에 의해 제한되는 서해를 마주하고 있는 군산의 경우 작은 Scale Coefficient, 큰 Location Coefficient, 2.0 전후의 Shape Coefficient로 특정되었다. 서해와 남해가 만나는 해역을 마주하고 있는 목포의 경우 작은 Scale Coefficient, 큰 Location Coefficient, 제일 작은 Shape Coefficient를 지녀 남해와 서해의 해양환경이 혼재한다는 사실도 확인할 수 있었다.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2008년도 춘계 학술발표회 초청강연 및 논문집
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• pp.858-862
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• 2008

KICT has been carrying out inventory research on the cut slopes of national roads. Inventory research results are basic data used in cut slope management system. Inventory data are classified by general status, cut slope characteristics and inspector opinion. Cut slope inventory data are utilized to figure out dangerous slopes and decide survey ranking of detailed safety diagnostication. This paper drew the distribution of dangerous cut slopes using inventory data in Chungcheongdo, then verified an efficiency on distribution of dangerous cut slopes by comparing occurrence frequency of real collapsed cut slopes.