• 대기
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• 제22권4호
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• pp.415-427
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• 2012

$CO_2$ is the most important trace gas related to climate change. Therefore, understanding surface carbon sources and sinks is important when seeking to estimate the impact of $CO_2$ on the environment and climate. CarbonTracker, developed by NOAA, is an inverse modeling system that estimates surface carbon fluxes using an ensemble Kalman filter with atmospheric $CO_2$ measurements as a constraint. In this study, to investigate the capability of CarbonTracker as an analysis tool for estimating surface carbon fluxes in Asia, an experiment with a nesting domain centered in Asia is performed. In general, the results show that setting a nesting domain centered in Asia region enables detailed estimations of surface carbon fluxes in Asia. From a rank histogram, the prior ensemble spread verified at observational sites located in Asia is well represented with a relatively flat rank histogram. The posterior flux in the Eurasian Boreal and Eurasian Temperate regions is well analyzed with proper seasonal cycles and amplitudes. On the other hand, in tropical regions of Asia, the posterior flux does not differ greatly from the prior flux due to fewer $CO_2$ observations. The root mean square error of the model $CO_2$ calculated by the posterior flux is less than the model $CO_2$ calculated by the prior flux, implying that CarbonTracker based on the ensemble Kalman filter works appropriately for the Asia region.

• 한국수산과학회지
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• 제27권5호
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• pp.659-672
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• 1994

진해만의 저서동물 군집에 대해 Sanders(1968)의 희박법(Rarefaction method), Warwick(1986)의 개체수-생물량 비교법(Abundance-Biomass Comparison method), Gray(1979)의 대수-정규분포 응용법 (Log-Normal Distribution method) 및 Frontier(1985)의 순위-빈도 곡선법 (Rank-Frequency Diagram method) 등의 환경 평가 기법을 이용하여 진해만의 오염정도를 평가하였다. 이 방법들 가운데 개체수-생물량 비교법은 오염해역에 개체당 생물량이 큰 이매패류인 Periglypta cf. puerpera와 Macoma tokyoensis와 다모류인 Nectoneanthes multignatha가 출현함으로서 이 방법의 원리에서 요구하는 전제 조건을 잘 반영하지 못하였다. 그러나 나머지 3가지 방법은 진해만의 환경을 잘 반영하고 있었으며, 가장 내만에 위치한 Group-I이 가장 오염된 해역으로 나타났으며 진해만 중앙부 해역인 Group-II도 상당히 오염이 진행된 것으로 나타났다. 그러나 진해만 입구인 Group-III과 VI는 내만 해역에 비해 상대적으로 오염의 영향이 적은 것으로 나타났다. 이러한 방법들 가운데 종별 개체수 자료만을 필요로 하는 대수-정규 분포 응용법이 오염을 평가하는데 가장 편리하고 적합한 것으로 판단되며, 그 밖의 희박법 및 순위-빈도 곡선도 상대적 평가 방법으로는 유익한 수단이 된다. 우리나라의 다른 해역에서의 오염평가도 저서동물의 분포특성을 이용한 이러한 다양한 환경평가 기법을 시도해 보는 것이 바람직할 것으로 생각된다.

• 대한인간공학회지
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• 제30권3호
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• pp.409-418
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• 2011

Objective: This study was performed to evaluate the child-care teachers' job in relation to physical work. Background: Child-care teacher is directly related to the quality of child care. And their physical activity is higher than general education teachers because the proportion of day care is high. But analyzes of child-care teachers' job burdens and the work environment associated with physical activity is not well established. Method: To conduct this study, the child-care teachers' job was classified into 18 physical works. After classification, posture was evaluated by ergonomic posture evaluation schemes of OWAS, RULA, REBA and evaluated for each physical part. Next, musculoskeletal subjective symptoms were analyzed. Results: The results showed the following: The highest assessment on the posture evaluation was "helping children to ride a school bus", "feeding: meal/snack", "brushing children's teeth" and "arrangement of nap-stuff". The rank of high-risk assessment on the neck/trunk/leg part was arranged by: "feeding: meal/snack", "helping children to ride a school bus", "making nap", "arrangement nap-stuff" and "brushing children's teeth". The rank of high-risk assessment on the upper limbs part was arranged by: "helping children to ride a school bus", "the bust - group activity", "meal/snack time - preparing, feeding, arrangement", "nap time - preparing, arrangement", "brushing children's teeth", and "using the toilet". According to the results of each musculoskeletal subjective symptom, teachers ordered the pain area as follows: waist, shoulder, leg/feet, and neck, and they showed more pain on trunk than the upper limbs. Conclusion: To sum up the results from ergonomic posture evaluation and a subjective symptom, the following are high working pressures: "feeding: meal/snack", "the bust - group activity", "making nap", "brushing children's teeth" with deep bending and waist twisting, "helping children to ride a school bus", "brushing children's teeth" with lifting shoulder; "meal/snack time - preparing, arrangement", "nap time - preparing, arrangement", and "using the toilet" with moving or an up-down position in their job. Application: The results of this study might be information for improvement of the child-care teachers' job environment.

• 한국측량학회지
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• 제25권3호
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• pp.207-213
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• 2007

다수의 고정수신기를 이용하여 이동수신기의 위치를 정확히 측정하고자 하는 필요성은 계속적으로 대두되고 있었으나, 현재 사용되고 있는 대부분의 상용 소프트웨어에서는 단일기선에 대한 GPS 결과만을 제공하고 있다. 따라서 본 논문에서는 다수의 단일기선 결과를 이용하여 네트워크를 구성함으로써 이동수신기의 위치측정 정확도를 향상시키기 위한 방안을 연구하였다. 이를 위해 기존의 측지 망 조정 이론을 도입하여 이동수신기의 위치결정 분야에 적용함으로써 위치정확도 향상 뿐만 아니라 전체적인 네트워크의 안정에도 기여할 수 있음을 알 수 있었다. 또한 측지망의 계수부족(Rank-deficiency)을 제거하기 위해서 하나의 고정수신기의 위치를 고정시키는 방법(RLESS), 이동수신기의 바이어스(Bias)를 최소화하는 방법(BLIMPBE), 그리고 고정수신기의 위치에 확률적 제약 조건을 주는 방법(SCLESS)에 대해서 비교 분석하였다. 네트워크 기반의 위치결정을 통해서 3차원 평균제곱근오차(RMSE)는 최대 3.5cm에서 2.1cm 수준으로 향상되었고, 기준점의 위치정확도에 따라 BLIMPBE 및 SCLESS 방법을 적절히 적용하는 것이 바람직할 것으로 판단된다.

• 한국작물학회지
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• 제13권
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• pp.83-92
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• 1973

In order to compare the forage value and to promote the growth without the hindrance of rice transplanting period for several forage crops as prior crops of paddy field, this experiment was conducted. Three kinds of foliar application, such solution as Urea, Gibb. and Gibb. +Urea were applied to promote the growth. The results gained are summarized as follows; 1. According to the forage crops, there were large difference of yields. The rankings of yield were shown as follows; Fresh weightㆍDry weight : Oats. Italian rye grass. White clover. Corn. Soybean. Crude protein content: Soybean. White clover. Corn. Italian rye grass. Oats. Crude protein Yield: White clover. Italian rye grass. Oats. Corn. Soybean. 2. The ranking of suitable forage crops as prior crops of paddy field were Oats, Italian rye grass, White clover, but Corn and Soybean were unsuited. 3. In general, length of stem, length and width of leaf were enlarged such rank as foliar application of Urea, Gibb. and Gibb. + Urea solution. There were apt to be increased fresh and dry weight by growth of stem length, these trend were shown among all crops and between foliar applications of same crops. 4. All crops were shown not only promoted growth but also increased yield by every treatments. The order of application effects were as follows; Fresh weigthㆍDry weigth: Gibb., Gibb. +Urea, Urea. Crude protein content and yield: Urea, Gibb, Gibb. + Urea. 5. In Oats, heading date was more accelerated 1, 2 and 3 days than control by foliar application of Urea, Gibb. and Gibb. + Urea respectively.

• 한국컴퓨터정보학회논문지
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• 제17권2호
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• pp.127-137
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• 2012

최근에 매쉬업(mashups), 웹 3.0, JavaScript, AJAX (Asynchronous JavaScript XML) 등이 널리 사용되면서, 새로운 취약점들이 발견되고 있어 보안 위협이 더 증대되고 있다. 이러한 웹 애플리케이션 취약점과 보안 위협을 효율적으로 완화하기 위해, 그 취약점들을 위험도 기준으로 순서화하여 웹 애플리케이션의 개발 생명주기의 해당 단계에서 우선적으로 고려해야 한다. 본 논문에서는 미국 NVD(National Vulnerability Database)의 웹 애플리케이션 취약점에 대한 데이터를 분석하여, OWASP Top 10 취약점들의 위험도 산정 방법이 타당한 지를 검증하였다. 그 다음, OWASP Top-10 2010과 CWE (Common Weakness Enumeration) 데이터를 중심으로 웹 애플리케이션 취약점 정보를 분석하여 웹 취약점들을 사상시켜 순서화하고, 그 취약점들이 어떤 개발 생명주기 단계와 관련이 있는지를 제시하였다. 이를 통해 효율적으로 웹 보안 위협과 취약점을 예방하거나 완화할 수 있다.

• 한국컴퓨터정보학회논문지
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• 제6권1호
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• pp.113-118
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• 2001

본 연구는 전산화된 제조관리 시스템의 운영을 위한 관련 소프트웨어의 합리적 선정을 목적으로 한다. 제조관리 시스템의 운용 소프트웨어는 구입비용이 대단히 크고 또한 공장 시스템의 환경에 적용 가능하여야 하기 때문에 자동화 제조관리 시스템의 운용 소프트웨어에 대한 합리적 선정이 생산성과 제조비용의 절감에 있어서 매우 중요하다. 본 연구는 다기준 의사결정모형을 이용한 제조관리 시스템의 운용을 위한 소프트웨어의 합리적 선정에 대한 방법을 제시하고 수치예제에 의해 타당성을 분석하였다.

• 산업공학
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• 제21권1호
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• pp.75-84
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• 2008

It is a difficult task for decision makers(DMs) to choose an appropriate release plan which balances the conflicts between water storage and hydro-electric energy generation in a multi-reservoir operation problem. In this study, we proposed a DEA-based ranking procedure by which the DM can rank the potential alternatives and select the best solution among the Pareto-optimal solutions. The proposed procedure can resolve the problem of mix inefficiency that may cause errors in measuring the efficiency of alternatives. We applied the proposed procedure to the multi-reservoir operation problem for the Geum-River basin and could choose the best efficient solution from the Pareto-set which were generated by the Coordinated Multi-Reservoir Operating Model.

• 방송공학회논문지
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• 제7권2호
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• pp.168-180
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• 2002

This paper proposes a novel method to detect unauthorized copies of digital images. This copy detection scheme can be used as either an alternative approach or a complementary approach to watermarking. A test image is reduced to 8$\times$8 sub-image by intensity averaging, and the AC coefficients of its discrete cosine transform (DCT) are used to compute distance from those generated from the query image, of which a user wants to find copies. Copies may be Processed to avoid copy detection or enhance image quality. We show ordinal measure of DCT coefficients, which is based on relative ordering of AC magnitude values and using distance metrics between two rank permutations, are robust to various modifications of the original image. The optimal threshold selection scheme using the maximum a posteriori (MAP) criterion is also addressed.

• 한국연소학회지
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• 제16권1호
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• pp.1-7
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• 2011

340 MWe circulating fluidized bed (CFB) boiler in Yeosu power station is under construction. The circulating fluidized bed boiler in the Yeosu power plant has a number of differences from other domestic boilers in terms of scale and design. Evaluation of design parameters of the Yeosu CFB boiler should be required because the direct application of existing technology is limited. In this study, design characteristics of the Yeosu CFB boiler was summarized. And thermogravimetric analysis was conducted with comparing other rank coals. Watersteam side heat absorption, flue gas temperature and heat transfer coefficient were calculated by heat and mass balance. Design parameters for the Yeosu CFB boiler were discussed along with typical value in the CFB design range.