• 한국환경과학회지
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• 제26권1호
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• pp.119-131
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• 2017

This study evaluated the feasibility of recovering and recycling nitrogen (N) and phosphorus (P) from livestock excreta as struvite ($MgNH_4PO_4{\cdot}6H_2O$) in South Korea. Our experimental results showed that struvite precipitation was a very effective way to recover N and P from livestock excreta. Moreover, our study demonstrated that struvite precipitates from livestock excreta (SPL) contain higher concentrations of N, P, and magnesium (Mg) as compared to compost and liquid manure from livestock excreta. In addition, although SPL contain high concentrations of copper (Cu) and zinc (Zn), they meet the fertilizer criteria for concentrations of heavy metals. In South Korea, SPL cannot currently be used as a fertilizer due to legal constraints. Legal permission for SPL use would offer greater choice in livestock excreta management. In conclusion, recovery and recycling of N and P from livestock excreta as struvite can be an effective tool for managing nutrients in livestock excreta.

• 한국의류학회지
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• 제34권12호
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• pp.1980-1991
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• 2010

This study proposes the O P E N Triad framework as a future set of tools and perspectives for individual members and institutes to further their professional and academic potential as well as prospect and vitalize the future of the Korean Clothing and Textiles discipline through a global perspective. The millennial generation desires On-demand, Personal, Engaging, and Networked (O P E N) experiences effecting cultural change for creative and influential interaction in transactions, communication, and education. O P E N Individuals offers a WebSphere model as a holistic learning system that has a synergizing value of education across academic courses, industries, and cultures. Through a digitalized and virtualized class, it complements relevant technologies already familiar to the student population. By employing environmental scanning approaches, the most influential and viable future global issues related to the clothing and textiles discipline are identified and dialogued within O P E N Institutes. For future clothing and textiles institutes, this scanning allows them to be open to new ideas, to focus on inter-engagements, to collaborate among individuals, to associate as a part of web of people, organizations, and ideas, to personalize an institutes curricula, and to dialogue generative knowledge. O P E N Industries reveals three dominant future issues that cross academia and industry, sustainability, supply chain management, and social networking. In-depth interviews with U.S. industry experts identified interdependent gaps in global consumer experience practices and suggested the following gaps as future research areas: a standardized business model to the entrepreneurial model, strategic management to a sustainable competitive advantage, standardized to differentiated products, services and operations, market segmentation to global consumer clusters, business-driven marketplaces to consumer-engaged marketspaces, and excellent services to optimal experience. This O P E N Triad framework empowers millennial students, universities, and industries to anticipate and prepare for a radically changing world.

• 인간식물환경학회지
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• 제24권5호
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• pp.469-483
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• 2021

Background and objective: If the Nelumbo nucifera spreads in a wetland at a high density, it can have considerable positive and negative ecological effects on habitats. For this reason, it is necessary to precisely investigate the impacts of its rapid proliferation. This study was conducted to propose the distribution and management of N. nucifera, which can cause the degradation of wildlife habitats due to the rapid spread of internal and external environmental factors that may affect the Junam wetland ecosystem. Methods: For the investigation and analysis of physical and ecological characteristics, factors of the abiotic environment such as general weather conditions, topography and water depth structure, and soil and water quality analysis, and bioenvironment characteristics such as changes in the N. nucifera community distribution were evaluated. To assess whether the differences in the soil depth and physicochemical characteristics between the N. nucifera community and the aquatic plant community are statistically significant, a One-way ANOVA was executed. Results: N. nucifera was presumably introduced in approximately 2007 and observed at a prevalence of only 0.8% in 2009, but had expanded to 11.1% in 2014. After that, the area was increased to 19.3% in 2015 and 40.0% in 2017, about twice that of the previous survey year. The rapid diffusion of an N. nucifera colony can have adverse effects on wildlife habitats and biodiversity at Junam Wetland. To solve these problems, four management methods can be proposed; water level management, mowing management, installation of posts and removal of lotus roots. Control of the N. nucifera community using these methods was judged to be suitable for cutting and water level management when considering expansion rate, water level variation, and wildlife habitat impacts. Conclusion: As the biotic and abiotic environmental factors are different for each wetland, it is necessary to determine the timing and method of management through a detailed investigation.

• 한국경영과학회지
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• 제17권2호
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• pp.123-130
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• 1992

The model of k-out-of n : G repairable system with identical components is extended to a repairable system with n different components. The objective is to analytically derive the mean time of the busy period for a k-out-of-n : G system with unrestricted repair. Then, the lower and upper bounds on the average time of the busy period of the n-component system with restricted repair are also shown.

• 한국전문물리치료학회지
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• 제9권1호
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• pp.69-79
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• 2002

Many pregnant women have experienced low back pain (LBP) during pregnancy and after delivery, and it has been an important component in women health. This study was designed to investigate the characteristics and management of the LBP in postpartum women. Eighty-five postpartum women were participated in this survey. Mean age of 85 women was 28.1 years. Of 85 postpartum women, 55.3% (n=47) had LBP after pregnancy. Thirty of 47 women had pain on lumbar region, 17 postpartum women had pain on sacroilium region. Of 85 postpartum women, 74% (n=54) had LBP before pregnancy and 71.8% (n=61) had LBP during pregnancy. Of 47 postpartum women who had LBP, 83% (n=39) had not received medical management for LBP, 12.8% (n=6) took medication, and 4.3% (n=2) performed self-exercise. None of postpartum women had received physical therapy during pregnancy and after delivery for treatment low back pain. The pain in SI region was more severe than in lumbar region after pregnancy according to VAS (visual analog scale) (p<.05). However, there was no significant difference in VAS scores between SI pain and lumbar pain before and during pregnancy (p>.05). Pain region after delivery was related to pain region of pre-pregnancy and during pregnancy (p<.01). Pain level after delivery was related to the pain and night pain level during pregnancy (p<.01).

• 디지털산업정보학회논문지
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• 제11권4호
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• pp.61-68
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• 2015

MANET has various vulnerability in wireless network and is more vulnerable in security because central management is not performed. In particular, routing attack may decrease performance of the overall network because the mobile node acts as a router. In this paper, we proposed authentication technique for improving the reliability of the network by increasing the integrity of the routing control packet and blocking effectively attacks that occur frequently in the inside. The proposed technique is consisted of two authentication methods of ZCN and N2N. ZCN authentication method is to elect CA nodes and monitor the role of the CA nodes. N2N authentication method is for an integrity check on the routing packets between nodes. Index key is determined by combining the hop count value to shared key table issued from CA in order to increase the robustness of the internal attack. Also, the overhead of key distribution was reduced by distributing a shared key to nodes certificated from CA. The excellent performance of the proposed method was confirmed through the comparison experiments.

• 한국토양비료학회지
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• 제49권6호
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• pp.819-825
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• 2016

Monitoring of soil fertility and crop productivity in long-term application of silicate fertilizers is necessary to use fertilizers efficiently. This study was conducted to investigate effects of continuous application of silicate fertilizer for rice cultivation from 1969 to 2014. The treatments were no silicate fertilizer treatments (N, NC, NPK, and NPKC) and silicate fertilizer treatments (N+S, NC+S, NPK+S, and NPKC+S). The 46-yr input of $2\;ton\;ha^{-1}yr^{-1}$ of silicate fertilizer increased pH 0.6 ~ 1.1 and exchangeable Ca $2.0{\sim}2.4cmol_c\;kg^{-1}$ in silicate fertilizer treatments (N+S, NC+S, NPK+S, and NPKC+S) compared with no silicate fertilizer treatments (N, NC, NPK, and NPKC) because silicate fertilizer included Ca component. Also, available silicate concentrations of silicate fertilizer treatments (N+S, NC+S, NPK+S, and NPKC+S) increased $169mg\;kg^{-1}$ compared to no silicate fertilizer treatments. In Period II ('90~'14), the mean annual Si field balance varied from 62 to $175kg\;ha^{-1}yr^{-1}$ in silicate fertilizer treatments, indicating continuous accumulation of soil Si. Silicon uptake and grain yield of rice had greater differences between N treatment and N+S treatment than other treatments. This showed that the application of silicate fertilizer had greater effect in nutrient-poor soils than in proper nutrient soils. Thus the application of silicate fertilizer led to improvement the fertility of soil and increasement of rice production for the lack of soil nutrients.

• 한국품질경영학회:학술대회논문집
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• 한국품질경영학회 2006년도 추계 학술대회
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• pp.309-314
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• 2006

The linear Consecutive-k-out-of-n:F system consists of n component ordered linearly and fail if and only if at least k consecutive components fail. We assume that the components are independent and identical exponentially distributed. This paper develops a model to calculate the expected cost per unit time of a linear consecutive-k-out-of-n:F system. The optimization problem we consider regards the choice of the system structure parameter k to minimized the expected cost per unit time.

• 한국경영과학회지
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• 제17권1호
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• pp.31-41
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• 1992

An extension of generalized linear multiple choice knapsack problem [1] is presented and an algorithm of order 0([n .n$_{max}$]$_{2}$) is developed by exploiting its extended properties, where n and n$_{max}$ denote the total number of variables and the cardinality of the largest multiple choice set, respectively. A numerical example is presented and computational aspects are discussed.sed.

• 한국항해항만학회:학술대회논문집
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• 한국항해항만학회 2018년도 추계학술대회
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• pp.119-121
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• 2018

해상교통 환경변화에 부응하고 나아가 대형 해양사고 방지와 인명사고 예방을 위해 구축, 운영 중인 항로표지통합관리시스템을 2012년 제정된 "해양교통시설 통합관리시스템 표준규격서"를 준용하여 개선을 하고자 한다. 기존에 구축되어 운영 중인 시스템의 자원을 재활용하고 운용소프트웨어를 개선하며, 자국 시스템 설치에 있어 표준화하여 운영 및 유지관리가 용이하도록 한다.