• Journal of Positioning, Navigation, and Timing
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• 제10권2호
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• pp.153-158
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• 2021

In order to mitigate the vulnerability of the satellite navigation system against radio frequency interference, South Korea has been developing advanced terrestrial navigation system (eLoran) technology since 2016. The eLoran system synchronizes the transmission time of the pulse used in the existing Loran-C system with UTC and transmits correction information that can improve the position error. The eLoran system is known to reduce the position error of about 460 m of the existing Loran-C system to 20 m, and for this, the transmitter must be able to transmit eLoran signals according to more stringent standards. For this reason, an international standard that further developed the Loran-C signal standard established by US Coast Guard was established by Society of Automotive Engineers (SAE) International. In this paper, based on the analysis of the SAE9990 document, the international standard for eLoran transmission signals, a standard inspection process was produced to check whether the eLoran transmitter is transmitting signals in accordance with the standard.

• 대한수학회지
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• 제36권1호
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• pp.139-157
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• 1999

Consider a supercritical Bellman-Harris process evolving from one particle. We superimpose on this process the additional structure of movement. A particle whose parent was at x at its time of birth moves until it dies according to a given Markov process X starting at x. The motions of different particles are assumed independent. In this paper we show that when the movement process X is standard Brownian the proportion of particles with position $\leq${{{{ SQRT { t} }}}} b and age$\leq$a tends with probability 1 to A(a)$\Phi$(b) where A(.) and $\Phi$(.) are the stable age distribution and standard normal distribution, respectively. We also extend this result to the case when the movement process is a Levy process.

• 디지털산업정보학회논문지
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• 제7권1호
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• pp.173-183
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• 2011

Global logistics including Korea had developed at various fields through the developed IT technology. In addition, in changing into Internet based digital economy times, economic and logistics activities became extending into worldwide over the cross-border. Logistics activity performed by off-line rapidly changed in real environment. But, unfortunately business process modeling about the whole logistics was not happened, even though process modeling had done by transport stages or logistics entities. Therefore, it is difficult to grasp the whole logistics. Additional cost and time was requested due to no association between logistics entities and invisibility. So, this paper has to be process modeling for logistics industry domain. For objective modeling, work area shall be divided and it extracts general work process per each area. And then it defines subprocess of general work process. Cargo tracking in logistics industry domain means to grasp the status and present states at transportation or storage stage. This paper defines business process and data model for electronic processed work area using the UN/CEFACT standard modeling methodology.

• 한국축산식품학회지
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• 제23권1호
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• pp.70-74
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• 2003

국민소득의 증가와 수입자유화에 따라 치즈 소비량도 매년 증대되어 1991년 8천 5백톤에서 2001년에는 5만 3천여톤으로 10년간 6배 이상의 소비증대를 나타내었으며, 같은 기간 신선한 치즈(H.S. 0406.10.1000)의 수입량도 2톤, 3만 달러에서 2만톤, 4천 9백만 달러로 양으로는 만 배, 금액으로는 1,600여배 증가하였다. 또한, 가공 치즈에 있어서도 1991년 4,790톤에서 2001년 24,973톤으로 5.2배의 소비증가를 나타내었으나 성분규격 및 분류체계는 적절하지 못하게 규정되어 있다. 자연치즈의 경우 정의에 따라 총고형분이 유고형분과 차이가 없을 것으로 생각되며, 한 종의 연성치즈를 제외하고는 모두 규격을 만족시켰으나 유고형분 함량에 따라 '생치즈'와 '연성치즈'가 구별되지는 않았다. 따라서, CODEX의 규정을 참조하여 지방을 제외한 성분중 수분함량(MFFB)에 따라 초경질, 경질, 반경질, 연질로 구분하는 것이 치즈의 조직적 특성을 고려할 때 적절하리라 생각되며, 건물중 지방함량에 따라 60% 이상을 '고지방', 25∼60%를 '중지방', 25% 이하를 '저지방'으로 분류하는 것이 바람직하리라 생각된다. 가공치즈는 소비자의 기호에 따라 다양한 제품이 개발되고 있으며 앞으로도 더욱 소비확대가 기대되는 제품으로서, 유고형분 15∼34% 제품을 '치즈가공품'으로 분류하여 규정하는 것이 가공치즈의 개발 및 소비촉진을 위해 필요하다고 생각된다.

• 전기학회논문지
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• 제67권11호
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• pp.1477-1485
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• 2018

There are two major issues for activated sludge process in sewage treatment plant. One is how to make sewage be more clean and the other is the energy saving in sewage treatment process. The major monitoring sewage qualities are chemical oxygen demand, phosphorus, nitrogen, suspended solid in effluent. These are transmitted to the national TMS(Telemetry Monitoring System) at every hour. If these exceed the environmental standard, the environmental charges imposed. So, these water qualities are to be controlled below the environmental standard in operation of sewage treatment plant. And recently, the energy saving is also important in process operation. Over 50% energy is consumed in blowers and motors for injection oxygen into aeration tank. So, with the water qualities to be controlled below the environmental standard, the energy saving also is to be accomplished for efficient plant management. Almost researches are aimed to control water quality without considering energy saving. AI techniques have been used for control water quality. AI modeling simulator provided the optimal control inputs(blower speed, waste sludge, return sludge) for control water quality. Blower speed is the main control input for activated sludge process. To make sewage be more clean, the excessive blower speed is supplied, but water quality is not better than the previous. In results, non necessary energy is consumed. In this paper we propose a new method that the energy saving also is to be accomplished with the water qualities to be controlled below the environmental standard for efficient plant management. Water qualities in only aeration tank are used the inputs of fuzzy models. Outputs of these models are chemical oxygen demand, phosphorus, nitrogen, suspended solid in effluent and have the environmental standards. In test, we found this method could save 10% energy than the previous methods.

• Safety and Health at Work
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• 제13권4호
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• pp.493-499
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• 2022

Background: The purpose of this study is to construct a job-exposure matrix for lead that accounts for industry and work processes within industries using a nationwide exposure database. Methods: We used the work environment measurement data (WEMD) of lead monitored nationwide from 2015 to 2016. Industrial hygienists standardized the work process codes in the database to 37 standard process and extracted key index words for each process. A total of 37 standardized process codes were allocated to each measurement based on an automated key word search based on the degree of agreement between the measurement information and the standard process index. Summary statistics, including the arithmetic mean, geometric mean, and 95th percentile level (X95), was calculated according to industry, process, and industry process. Using statistical parameters of contrast and precision, we compared the similarity of exposure groups by industry, process, and industry process. Results: The exposure intensity of lead was estimated for 583 exposure groups combined with 128 industry and 35 process. The X95 value of the "casting" process of the "manufacture of basic precious and non-ferrous metals" industry was 53.29 ㎍/m³, exceeding the occupational exposure limit of 50 ㎍/m³. Regardless of the limitation of the minimum number of samples in the exposure group, higher contrast was observed when the exposure groups were by industry process than by industry or process. Conclusion: We evaluated the exposure intensities of lead by combination of industry and process. The results will be helpful in determining more accurate information regarding exposure in lead-related epidemiological studies.

• 한국IT서비스학회지
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• 제14권1호
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• pp.85-98
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• 2015

As we enter the technology and knowledge-intensive era, standardization has become a key element to increase the sustainability of companies. However, standardization activities have not been proceeded well due to lack of relevant information, financial and human resources and complexity of the authentication process. Thus, in this paper, we analyze the effect of understanding the internal and external standard trends surrounding companies and recognizing the difficulties of standardization process on the needs of standard/standardization education. We suggest an experiment model and associated variables for analysis based on the previous studies. The analysis results from 1,000 companies that belong to telecommunication industry and electrical and electronics industry showed positive relationships among these three variables. Furthermore, we propose major policy directions for increasing standardization effect.

• 한국항행학회논문지
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• 제7권2호
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• pp.206-210
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• 2003

본 논문에서는 최신의 미세공정인 0.18um CMOS 공정을 이용한 표준 셀 라이브러리를 설계하고, 이를 P&R(Placement and Routing) CAD 툴에 사용할 수 있도록 포팅한다. 제작결과를 검증하기 위하여 간단한 테스트칩을 제작하였으며 설계에 사용된 표준 셀 라이브러리는 0.18um 아남반도체의 공정이다. 이러한 설계 및 제작과정을 통하여 최신의 미세공정을 이용하여 디지털 시스템의 자동설계가 가능함을 확인하였다.

• 자동차안전학회지
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• 제12권3호
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• pp.27-33
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• 2020

In this paper, the process of predicting efficient durability performance for vibration durability test of automobile parts using vibration test load on automobile fuel tank is presented. First of all, the common standard load that can be applied to the initial development process of the automobile was used for the fuel tank and the vulnerability of the fuel tank to the vibration fatigue load was identified through frequency response analysis. In addition, the vulnerability of the fuel tank was re-enacted through vibration durability test results, and the scale factor was applied to the standard load. In order to predict the vibration durability performance required for detailed design, vibration fatigue analysis was performed on the developed vehicle with the frequency of vibration severity equivalent to the durability test, and the vulnerability and life span of the fuel tank were identified through the process of applying weights to these selected standard loads, thereby reducing the test time of the development vehicle.

• 전기학회논문지
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• 제61권5호
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• pp.770-776
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• 2012

For a few recent years, KECA(Korea Electrical Contractor Association) has promoted a project to establish an electrical construction specification called Master Spec. This paper analyses the characteristics of standards-making process of the Master Spec. as an umbrella technical standard in electrical construction industry in Korea. This paper argues that even if the Master Spec. is recognized to be technical standards, the standards-making process involves both technical and social practices when viewed from social construction theory and governance perspective. This aspect of social practices in technical standards making should be well understood because various stakeholders in terms of interests, resources, and motives try to influence the process positively and negatively. KECA in responsible for enactment of the Mater Spec. should be very thoughtful in building consensus first of all among electrical contractors, managing relationship with concerned government officials, and dealing with potential deviant groups as well as in pooling expertises and developing technical knowledge needed for designing technical specification.