• KSII Transactions on Internet and Information Systems (TIIS)
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• 제17권10호
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• pp.2658-2681
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• 2023

In edge computing scenarios, IoT end devices play a crucial role in relaying and forwarding data to significantly improve IoT network performance. However, traditional routing mechanisms are not applicable to this scenario due to differences in network size and environment. Therefore, it becomes crucial to establish an effective and reliable data transmission path to ensure secure communication between devices. In this paper, we propose a trusted path selection strategy that comprehensively considers multiple attributes, such as link stability and edge cooperation, and selects a stable and secure data transmission path based on the link life cycle, energy level, trust level, and authentication status. In addition, we propose the Stability-based On-demand Multipath Distance Vector (STAOMDV) protocol based on the Ad hoc AOMDV protocol. The STAOMDV protocol implements the collection and updating of link stability attributes during the route discovery and maintenance process. By integrating the STAOMDV protocol with the proposed path selection strategy, a dependable and efficient routing mechanism is established for IoT networks in edge computing scenarios. Simulation results validate that the proposed STAOMDV model achieves a balance in network energy consumption and extends the overall network lifespan.

• Current Photovoltaic Research
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• 제12권1호
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• pp.17-23
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• 2024

Photovoltaic (PV) power generation is the world's best and largest renewable energy that generates electricity with infinite sunlight. Solar cell modules are a component of photovoltaic power generation and must have a long-term durability of at least 25 years. The development of processes and equipment that can be recovered through the recycling of metals and valuable metals when the solar module's lifespan is over has been completed to the level of commercialization, but few processes have been developed that require repair due to initial defects. This is mainly due to the economic problems caused by remaking. However, if manufacturing processes such as repairing solar cell modules that have been proven to be early defects are established and the technical review of long-term reliability and durability reaches a certain level, it is considered that it will be a recommended process technology for environmental economics. In this paper, assuming that a defective solar cell module occurs artificially, a manufacturing process for replacement of solar cells was developed, and a technical verification of the manufacturing technology was conducted through long-term durability evaluation in accordance with KS C 8561. Through this, it was determined that remanufacturing technology for solar cell replacement of solar cell modules that occurred in a short period of time after installation was possible, and the research results were announced through a journal to commercialize solar modules using manufacturing technology in the solar market in the future.

• 자원리싸이클링
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• 제33권2호
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• pp.16-23
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• 2024

해수나 염수에서 마그네슘을 추출하는 전해 반응은 마그네슘 이온을 주로 수산화마그네슘 형태로 마그네슘을 침전-회수하는 기술로, 양이온교환막, 음이온교환막, 전기투석, 비막 방식 등으로 분류된다. 최근 연구는 마그네슘 함유 해수나 염수를 사용하여 마그네슘의 회수 효율성 및 선택성 증진에 집중되며, 향후 일반 해수를 사용할 경우에도 효과적인 마그네슘 회수가 기대된다. 향후에는, 스케일업 시스템의 장기운전을 통해 마그네슘 및 다양한 유가물질에 대한 선택적 고효율 회수의 최적화와 더불어 경제성 및 환경성을 증진하는 것이 중요하다. 함께 막의 수명 및 교체주기를 고려하여 운전비용을 현실적으로 산정해야 하며, 다양한 인자에 대한 모니터링 데이터를 기반으로 상세하고 실용적인 공정 모델이 필요하다.

• 한국수자원학회논문집
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• 제48권9호
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• pp.711-717
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• 2015

본 논고는 고양 정수장과 구미 정수장으로부터 물을 공급받고 있는 5개 도시(고양, 파주, 구미, 김천, 칠곡)를 대상으로 고도정수처리 도입의 경제적 편익을 평가하였다. 지불가능금액(WTP) 추정을 위한 방법으로는 이중경계 양분선택형 CVM을 이용하였다. 특히 평균 WTP 추정값을 도출하기 위한 방법으로 모수 추정법 중 구간 데이터(interval-data) 모델을 이용하였다. 고도정수처리서비스에 대한 추가 지불 WTP(평균)는 공변량을 포함한 모델을 적용하였을 경우 톤당 231.3원이, 공변량을 포함하지 않은 모델을 적용하였을 경우에는 231.2원인 것으로 추정되었다. 한편 추정된 WTP와 함께 고양 및 구미 정수장으로부터 공급받는 수돗물 공급량(각각 59.675 백만$m^3$/년, 93.734 백만$m^3$/년)을 고려하여 정수장별 고도정수처리의 경제적 편익을 도출한 결과 고양정수장은 약138억 원/년이, 구미정수장은 16.8억 원/년으로 추정되었다. 그리고 설비의 내구연한을 10년으로 가정할 경우, 비용 대비 편익 비율은 고양정수장이 3.7, 구미정수장이 2.1로 조사되었다. 수도사업 관련 고도정수처리 도입은 공공사업의 한 유형으로, 이는 경제적 편익 및 비용이 동시에 고려되어야 할 정책적 사업이다. 이러한 의미에서 본 연구의 산출물인 고도정수처리의 WTP는 정책결정자의 수질개선 관련 의사결정에 기초 자료가 될 것이다.

• 산업경영시스템학회지
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• 제46권1호
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• pp.84-90
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• 2023

ASL estimation of public building is based on how appropriate the maximum age of the asset is derived based on the age record of the asset in the statistical data owned by public institutions. This is because we get a 'constrained' ASL by that number. And it is especially true because other studies have assumed that the building is an Iowa curve R3. Also, in this study, the survival rate is 1% as the threshold value at which the survival curve and the predictable life curve almost coincide. Rather than a theoretical basis, in the national statistical survey, the value of residual assets was recognized from the net value of 10% of the acquisition value when the average service life has elapsed, and 1% when doubling the average service life has elapsed. It is based on the setting mentioned above. The biggest constraint in fitting statistical data to the Iowa curve is that the maximum ASL is selected at R3 150%, and the 'constrained' ASL is calculated by the proportional expression on the assumption that the Iowa curve is followed. In like manner constraints were considered. First, the R3 disposal curve for the RCC(reinforced cement concrete) building was prepared according to the discarding method in the 2000 work, and it was jointly worked on with the National Statistical Office to secure the maximum amount of vintage data, but the lacking of sample size must be acknowledged. Even after that, the National Statistical Office and the Bank of Korea have been working on estimating the Iowa curve for each asset class in the I-O table. Another limitation is that the asset classification uses the broad classification of buildings as a subcategory. Second, if there were such assets with a lifespan of 115 years that were acquired in 1905 and disposed of in 2020, these discarded data would be omitted from this ASL calculation. Third, it is difficult to estimate the correct Iowa curve based on the stub-curve even if there is disposal data because Korea has a relatively shorter construction history, accumulated economic wealth since the 1980's. In other words, "constrained" ASL is an under-estimation of its ASL. Considering the fact that Korea was an economically developing country in the past and during rapid economic development, environmental factors such as asset accumulation and economic ability should be considered. Korea has a short period of accumulation of economic wealth, and the history of 'proper' architectures faithful to building regulations and principles is short and as a result, buildings 'not built properly' and 'proper' architectures are mixed. In this study, ASL of RCC public building was estimated at 70 years.

• 한국식품영양학회지
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• 제30권2호
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• pp.371-377
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• 2017

Muscle atrophy is characterized by a decrease in the mass of the muscle. With an increase in life expectancy and chronic illnesses, the incidence of muscle atrophy is increasing and the quality of life of patients is decreasing. Thus, reducing muscle atrophy is of high clinical and socio-economic importance. Mistletoe is a semi-parasitic plant that has been used as a traditional medicine in many countries to treat various human illnesses. It has been reported that Korean mistletoe extract (KME) has diverse biological functions including anti-tumor, anti-oxidant, anti-diabetic, anti-obesity properties, and extension of lifespan. Especially, we have recently reported that KME improves exercise endurance in mice, indicating its beneficial roles in enhancing the capacity of skeletal muscle. In this study, we investigated whether KME could activate the signaling pathway related to protein synthesis in a mouse model of muscle atrophy. Interestingly, KME efficiently activated the Akt/mTOR pathway, and Akt and mTOR are important signaling hub molecules for the acceleration of protein synthesis in muscle cells. In addition, KME also increased the activity of S6 kinase which is involved in the regulation of muscle cell size. Moreover, the ERK activity, required for transcription of ribosomal RNA for protein synthesis, was also enhanced in KME-treated mouse muscle. These data support the idea that KME increases muscle mass via increased protein synthesis. Our findings also suggest that Korean mistletoe might be a promising candidate for the development of functional foods that are beneficial for preventing muscle atrophy.

• 한국도로학회논문집
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• 제14권6호
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• pp.25-35
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• 2012

PURPOSES : Hollows are easily made, and bearing capacity can be lowered near underground structures because sublayers of pavement settle for a long time due to difficult compaction at the position. If loadings are applied in this condition, distresses may occur in pavement and, as the result, its lifespan can decrease due to the stress larger than that expected in design phase. Although reinforced slab is installed on side of box culvert to minimize the distresses, length of the reinforced slab is fixed as 6m in Korea without any theoretical consideration. The purpose of this paper is investigating the behavior of concrete pavement according to the cover depth of the box culvert ad the length of the reinforced slab. METHODS : The distresses of concrete pavement slabs were investigated and cover depth was surveyed at position where the box culverts were located in expressways. The concrete pavements including the box culverts were modeled by finite element method and their behaviors according to the soil cover depth were analyzed. Wheel loading was applied after considering self weight of the pavement and temperature gradient of the concrete pavement slab at Yeojoo, Gyeonggi where a test road was located. After installing pavement joint at various positions, behavior of the pavement was analyzed by changing the soil cover depth and length of the reinforced slab. RESULTS : As the result, the tensile stress developed in the pavement slab according to the joint position, cover depth, and reinforced slab length was figured out. CONCLUSIONS : More reasonable and economic design of the concrete pavement including the box culvert is expected by the research results.

• Tribology and Lubricants
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• 제32권4호
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• pp.113-118
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• 2016

As an economic, high quality, and highly reliable gear with low noise and low vibration is demanded, an overall finite element analysis regarding a gear is required. Also, an infrared thermography test, which is a quantitative testing technique, is demanded for safety and longer lifespan of gear products. In order to manufacture a gear product or to determine safety of a gear being used, it is necessary to precisely determine ingredients of a material constituting a gear and detect any internal defect. This study aims to realize a design that minimizes the spur gear displacement with respect to power during its rotation and ensures the spur gear control capacity by using a 3D model and the midasNFX program. This facilitates the assessment of the possibility of cracking by evaluating the stress intensity and focusing on the integrity of the spur gear. We prepare the specimen of the spur gear based on the possibility of cranking as per the result of the structural interpretation from an infrared ray thermal measuring technique. After cooling the spur gear, we perform experiments using thermography and halogen lamps and analyze the temperature data according to the results of the experiment. In the experiment which we use thermography after cooling, we find a rise in the temperature of the room. As a result, the defective part show temperatures lower than their surroundings while the normal parts have temperatures higher than the defective parts. Therefore, it possible to precisely identify defective part owing to its low temperature.

• 의료법학
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• 제10권1호
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• pp.213-260
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• 2009

While the medical supplies have positive functions such as extending lifespan, recovering health, and preventing diseases, they also cause unexpected tragic consequences due to their side effects, and the magnitude of such damage inevitably increases due to the mechanism of mass production, mass distribution, and mass consumption of those medical supplies. Therefore, needless to say, the optimal way to prevent or reduce such damage is rather through medical supply manufacturers' producing non-defective products, or through the government's controlling production and sales of medical supplies with more aggressive exercise of regulatory authority on medical supply manufacturers, than through a remedy by a legal relief after using medical supplies. In this case, although the victim died due to the defect of the cold medicine, 'CONTAC 600', the drug company's responsibility to cover damages was not recognized because a defect could not be found in the then-manufacturing process. Thus, while pharmaceutical companies are gaining economic profits by producing and selling a medical supplies, if they do not take any remedy measures for the victims of their products' side effects, the victims have to use medical supplies under their own responsibility of taking a risk, and they have to accept the full damage of the potential consequence. Therefore, to remove such absurdity and contradiction, and to practically remedy the victim of medical supplies' side effects, the pharmaceutical side effects remedy project pending in the the Drugs, Cosmetics and Medical Instruments Lawneeds to be actively implemented.

• 디지털산업정보학회논문지
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• 제15권1호
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• pp.133-155
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• 2019

The economic growth has made our lives more prosperous than the past, and the development of science fueled the era of 100-year lifespan. It is now distinct to us that preparation for life after retirement is not a choice but an imperative. In the meantime, outplacement programs have driven many to challenge and start a new chapter in life. This paper measures the characteristics of outplacement programs based on the self-determination factors; empirically examines how those characteristics influence on learning performance through self-efficacy and psychological well-being; concludes by proposing effective and productive ways for young adults and senior employees who are in search for new jobs. To test the research hypothesis, a survey was conducted among job searchers who have been previously provided with outplacement programs. The results are as follows: First, self-perceived autonomy has significant influences on self-efficacy and psychological well-being. Second, self-perceived competency has significant influences on self-efficacy and psychological well-being. Third, perceived relationship has no significant influence on self-efficacy and psychological well-being. Fourth, self-efficacy showed significant influences on psychological well-being, while not showing on learning performance. Fifth, psychological well-being has no significant influence on learning performance. This paper finds its academic significance in its theory-based approach to outplacement service program; research variables and examination are not based on researcher's arbitrary choice. This paper is also practically significant in that it discovered that outplacement service alleviates psychological stress caused by job relocation, and guarantees stable life after retirement.