• Proceedings of the Korea Water Resources Association Conference
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• 2023.05a
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• pp.297-297
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• 2023

최근 친수성, 경관, 생태계 보전 등을 위해 다양한 호안블록의 시공이 이루어지고 있어 호안블록의 수리적 안정성에 관한 관심이 증가하고 있다. 이러한 배경 하에 한국건설기술연구원 안동하천실험센터(이하 센터)에서는 2019년부터 실규모 수로를 이용하여 여러 건의 호안블록 실규모 수리검토 실험을 실시한 바 있다. 본 연구는 그간의 실험 결과를 종합적으로 고찰하고 수리 검토 실험의 현황과 한계점, 그리고 개선 방향을 제언하는데 그 목적이 있다. A1 수로(급경사수로, 하상경사 1/70)에서는 7건(21회), B1 수로(고유속수로, 하상경사 1/7)에서는 2건(6회)의 실험이 수행되었다. A1 수로 실험의 유량-소류력 관계는 1.0 m³/s에서 약 20 N/m²이며, 1.0 m³/s 증가당 약 11 N/m²이 증가하는 관계를 나타낸다. 7건의 실험 결과 30분 이상 지속된 최대 실험 유량은 6~7 m³/s 정도이며, 이는 A1 최대 공급 유량의 75 % 정도로서 안정적인 수준이라고 판단된다. 이 때의 최대 소류력은 75 N/m² 정도로 나타났다. B1 수로는 5 m/s 이상의 고유속 흐름을 발생시킬 수있으며, 2건의 실험 결과 0.5 m³/s에서 약 100 N/m², 최대 4.5 m³/s에서 330 N/m²까지 소류력을 제공하여 실험을 수행한 바 있다. 따라서 A1, B1 수로를 통해 제공할 수 있는 소류력 범위는 10~330 N/m²이지만, 75~100 N/m²는 실험에서 제공된 바 없었다. 한편, 토양유실의 경우 수준측량에 의해 측정되는데, 대부분의 실험에서 Clopper의 토양손실 지수(1.27 cm) 미만의 결과가 발생하였다. 이는 시험체에 따라 여건이 다르기는 하지만, 수리 검토 실험시 3회 실험을 기본으로 하고 있고 호안재료의 침식이 기준 이하로 유지되면서 최대한의 성능을 발휘할 수 있는 소류력 조건을 얻으려는 실험 목적에 부합하도록 조절된 것으로 볼 수 있다. 이러한 실험 결과를 토대로 고려해볼 수 있는 개선 방향은 다음과 같다. 강성 재료가 아닌 연성 또는 친환경적 호안재료의 허용 소류력 범위를 보다 넓게 평가하기 위해 A1 수로가 제공하는 최대 소류력을 높일 필요가 있다. 이를 위해 기본 3회의 실험 외에 추가로 호안블록이 파괴되거나 토양유실 임계치를 초과할 수 있는 실험을 수행함으로써 각 제품의 한계 성능을 평가하는 것이 필요할 것으로 보인다.

• Journal of the Korean Society for information Management
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• v.40 no.3
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• pp.119-142
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• 2023

Copyright is a legal criterion for determining the scope and method of digital library service. Works with expired protection periods correspond to the public domain and can be freely used by anyone. For this reason, it is a priority consideration in digital library construction and services. The purpose of this study is to examine how actively libraries are using expired protected works for digital library services. To this end, the relevant provisions of the Copyright Act applied to the construction and service of digital libraries were first summarized, and the meaning of the copyright protection period was theoretically examined. The current status of online services for expired works by the National Library of Korea was examined, focusing on the works of three Japanese colonial era writers, Kim Yoo-jung, Lee Hyo-seok, and Chae Man-sik, to check the specific service status of expired works. It reveals that the National Library of Korea is not fully utilizing the scope of the law, and that this situation is linked to the rights of other authors included in the book. Based on these results, it suggests that there is a need to change the service unit to focus on copyrighted works and to use authority records to systematize the management of authors' death years.

• Journal of the Korean Society of Marine Environment & Safety
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• v.29 no.5
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• pp.497-504
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• 2023

In this study, Selective catalytic reduction (SCR) + Diesel particulate filter (DPF) system was installed on a ship with a low-speed engine to conduct the on-board test. The target ship (2,881 gross tons, rated power 1,470 kW@240 rpm ×1) is a general cargo ship sailing in the coastal area. Drawing development, approvals and temporary survey of the ship were performed for the installation of the after-treatment system. For performance evaluation, the gaseous emission analyzer was used according to the NOx technical code and ISO-8178 method of measurement. The particulate matter analyzer used a smoke meter to measure black carbon, as discussed by the International Maritime Organization (IMO). Tests were conducted using MGO (0.043%) and LSFO (0.42%) fuels according to the sulfur content. The test conditions were selected by considering the engine rpm (130, 160 and 180). Gaseous emission and particulate matter (smoke) were measured according to the test conditions to confirm the reduction efficiency of the after treatment system. The results of NOx emission and particulate matter (smoke) revealed that reduction efficiency was more than 90%. The exhaust pressure met the allowable back pressure (less than 50 mbar). This study confirms the importance of the on-board test and the potential of SCR + DPF systems as a response technology for reducing nitrogen oxides and particulate matter.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.42 no.2
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• pp.197-208
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• 2022

The existence of shallow bedrock and the desire to use underground space necessitate the use of blasting methods. The standard blasting method under water after drilling is associated with certain technical difficulties, including reduced detonation power, the use of a fixed charge per delay, and decoupling. However, there is no blasting method to replace the existing blasting method. In this paper, a dry hole charged with ANFO blasting is assessed while employing a dry hole pumping system to remove water from the drill borehole. Additional standard blasting is also utilized to compare the blasting performances of the two methods. The least-squares linear regression method is adopted to analyze the blasting vibration velocity quantitatively using the measured vibration velocity for each blasting method and the vibration velocity model as a function of the scaled distance. The results show that the dry hole charged with ANFO blasting will lead to greater damping of the blasting vibration, more energy dissipation to crush the surrounding rock, and closer distances for the allowable velocity of the blasting vibration. Also, standard blasting shows much longer influencing distances and a wider range of the blasting pattern. The pilot test confirms the blasting efficiency of dry hole charged with ANFO blasting.

• Korea Trade Review
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• v.43 no.4
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• pp.111-130
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• 2018

In December 2015, the Paris Agreement was adopted to cope with global warming caused by greenhouse gas emission and to prevent the average temperature of the Earth from rising. Renewable energy sources have become important to address environmental problems such as rising sea levels, depletion of forests and fine dust. In order to grow renewable energy, government support is needed. However, excessive government support for the renewable energy industry could pose problems that include undermining fair competition and raising costs. The WTO already has heard cases involving renewable energy subsidies. This article focuses on subsidies and countervailing tariffs as well as examines WTO disputes related to renewable subsidies, and also analyze legal issues that are problematic in granting subsidies for the development of new renewable energy industries. In WTO dispute involving renewable energy subsidies, legal issues are SCM Agreement article 2 Specificity, article 3 (b) import substitution subsidy and GATT article 20. This paper proposes improvement measures such as the reintroduction of article 8 Non-Actionable Subsidies or special provisions on energy subsidy. In addition, it is necessary to clarify the interpretation of Article 3 of the subsidy agreement. However, excessive government subsidies can lead to trade friction, so the WTO rules should be improved in line with the WTO goals of environmental protection, equity in free trade, and sustainable development.

• Journal of Teachers' Pension
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• v.2
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• pp.47-102
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• 2017

오늘날 대다수의 선진 국가들은 고령화 사회에 대비하여 자국의 노후소득보장 제도를 대대적으로 개혁해 오고 있다. 우리나라의 경우에서도 지난 2015년 사학연금제도의 개혁이 이러한 취지에 해당될 수 있을 것이다. 본 연구에서는 고령화 사회의 문제가 단순히 노인부양비용의 증가 그 자체가 아니라, 평균수명의 증가에도 불구하고 늘어나게 된 노후의 삶에 대한 시간적 배분이 근로와 여가에 걸쳐 균형적으로 이루어지지 않고, 사회적 부양을 필요로 하는 노후의 여가만 일방적으로 늘어나고 있다는 점을 문제점으로 지적하였다. 따라서 이러한 차원에서 볼 때 고령화 사회의 문제는 생애근로기간의 연장을 통해서만 효과적으로 극복할 수 있을 것으로 생각된다, 하지만 이와는 반대로 개인별로 건강상태나 가족상황 등의 이유로 생애근로주기의 연장이 불가능한 사람들을 위하여 별도의 제도적 장치가 추가적으로 마련되어야 할 것이다. 종합해 보면, 고령화 사회의 노동시장 문제는 개인별로 다양한 욕구나 능력을 반영하여 각자에게 다양한 선택권을 보장해 줄 수 있는 방향으로 개선되어야 할 필요가 있다. 본 연구에서는 고령화 사회에 대비하여 연금수급연령 상향조정의 필요성을 사학연금제도를 중심으로 살펴보고, 대신 그로 인해 발생할 수 있는 소득공백문제와 연금가입경력 공백문제 등 제반의 충격을 흡수할 수 있는 제도적 장치로서 점진적 퇴직제도의 도입방안을 제안하였다. 개략적으로 사학연금제도에 있어서 점진적 퇴직모형은 법정연금수급연령의 인상 일정에 따라 다음과 같이 운영하는 방안을 제안하였다. 먼저 법정연금수급연령이 60세로 유지되는 2022년까지의 단기적 대책으로서 여기서 점진적 퇴직의 자격연령은 모든 가입자에게 60세로 적용하도록 한다. 이 경우 가입자들의 신분구분에 따라 각각 교수 5년, 교원 2년(문제해결에 대한 정책적 의지에 따라 이행구간을 확장할 수도 있음) 그리고 교직원 0년의 조기의 점진적 퇴직이 허용되므로, 현재 교원이나 교수의 임용대란문제에 효과적으로 대응을 할 수 있는 장점이 있다. 다음으로는 2023년 이후 2033년 사이 법정연금수급연령의 인상단계에 해당되는 기간 동안의 대책으로서 여기서는 교수, 교원, 교직원에게 적용되는 정년연령과 매년도 법정연금수급연령 사이의 기간을 조기의 점진적 퇴직 이행구간으로 정하도록 한다. 그리고 이러한 이행구간에 상당하는 기간만큼 후기의 점진적 퇴직 이행구간을 별도로 설정하여 그에 적절한 혜택이 주어질 수 있도록 한다. 마지막으로 2033년 이후부터는 교수, 교사, 교직원의 신분구분 없이 모두에게 적용되는 사항으로서 65세를 기준으로 그 이전의 5년은 사학연금의 적용을 받는 조기의 점진적 퇴직 그리고 그 이후의 5년은 국민연금의 적용을 받는 후기의 점진적 퇴직이 이루어질 수 있도록 한다. 그리고 전체 10년의 점진적 퇴직 이행구간 동안 개인별로 퇴직시점이나 퇴직형태의 선택이 자유롭게 이루어질 수 있도록 하기 위하여 보험수리의 원칙에 입각한 감액률 또는 가산율의 엄격한 적용을 제안하였다. 그리고 고령계층이 자신의 근로시간을 단계적으로 단축할 수 있도록 하고, 그 과정에서 발생하게 되는 소득의 감소부분은 별도의 제도적 방법(가교연금, 시간가치적립계정 등)으로 충당하도록 하는 방안을 제안하였다. 나아가 점진적 퇴직제도의 운영방식은 근로시간의 단축뿐만 아니라 작업부담의 경감 등에 대해서도 인정을 해주도록 해줌으로써 임금피크제도의 기능과 연계가 가능할 수 있도록 할 것을 제안하였다.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.30 no.4D
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• pp.377-386
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• 2010

This study was conducted to find out the characteristics of the expanded road embankment constructed by the lightweight air-mixed soil (slurry density $10kN/m^3$) for a short-term without any ground improvement. Compression strength, capillary rise height of the lightweight air-mixed soil and settlement behavior of soft ground were studied. Compression strengths of the specimens sampled at the site after 1 and 5 months of construction were all satisfied the required strength 500 kPa. However, it was not convinced the homogeneity construction, because the values of strength were depending on the sampled location. Also, strength difference between laboratory and site specimens were found about 19%, and thus it should be considered for mixing design. Capillary rise reached about 20 cm for 70 hours because of a numerous tiny pores existed inside the lightweight air-mixed soil. Relationship between settlement and time of the soft ground placed underneath the expanded embankment was estimated by using the measured data and back analysis technique. The current average consolidation ratio and the final settlement after 120 months later were estimated about 32% and 4.5cm, respectively. This settlement is much less value than the allowable settlement 10cm for this structure.

• Analytical Science and Technology
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• v.20 no.1
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• pp.84-90
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• 2007

To determine levels of 11 sulfonamides for animals in food, simultaneously, a selective method of high performance liquid chromatography with UV detector has been applied. The targets were sulfachlorpyridazine (SCP), sulfadiazine (SDZ), sulfadimethoxine (SDM), sulfisoxazole (SSX), sulfamerazine (SMZ), sulfamethazine (SMT), sulfamethoxazole (SMX), sulfamethoxypyridazine (SMP), sulfamonomethoxine (SMM), sulfaquinoxaline (SQX) and sulfathiazole (STZ). Food samples were beef, pork, chicken, milk and whole egg that were collected at the main 6 cities in Korea as Seoul, Busan, Daejon, Incheon, Mokpo and Gangneung. After homogenizing food samples with sodium phosphate solution and acetonitrile, it was extracted with n-hexane. The mobile phase gradient was a mixture of 5 mM potassium phosphate (pH 3.25) and methanol with a gradient ratio from 100:0 to 30:70. The UV wavelength was 270 nm. The overall recoveries were ranged from 75% to 95% and the limit of detection was minimum 0.004 mg/kg for SMT, and 0.007 mg/kg for STZ at signal/noise > 3, respectively. As results, sulfonamide drugs were not detected in most of the selected food samples, however, sulfamonomethoxine was detected in meat. The determined level of sulfamonomethoxine were 0.03 and 0.06 mg/kg for beef that were below the MRLs.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.26 no.5A
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• pp.841-848
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• 2006

There is a complex variation of stress in PSC anchorage zones and box girder diaphragms because of large concentrated load by prestress. According to the AASHTO LFRD design code, three-dimensional effects due to concentrated jacking loads shall be investigated using three-dimensional analysis procedures or may be approximated by considering separate submodels for two or more planes. In this case, the interaction of the submodels should be considered, and the model loads and results should be consistent. However, box girder diaphragms are 3-dimensional disturbed region which requires a fully three-dimensional model, and two-dimensional models are not satisfactory to model the flow of forces in diaphragms. In this study, the strengths of the prestressed box girder diaphragms are predicted using the 3-dimensional grid strut-tie model approach, which were tested to failure in University of Texas. According to the analysis results, the 3-dimensional strut-tie model approach can be possibly applied to the analysis and design of PSC box girder anchorage zones as a reasonable computer-aided approach with satisfied accuracy.

• Korean Journal of Poultry Science
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• v.50 no.2
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• pp.81-90
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• 2023

Animal welfare was introduced relatively late to Korea in comparison with Western countries. Nonetheless, the Korean government has continuously improved animal welfare-friendly regulations as policy instruments. Given the current situation, it is predicted that spontaneous settlement of the animal welfare policies will be difficult and may cause conflict in the farm animal industry. To identify and categorize conflicts caused by animal-welfare-related policies in the last five years, we investigated the awareness of animal welfare among Korean hen farms and the level of compliance with the animal welfare regulations. We collected a sample of 53 egg-laying chicken farm operators (e.g., owners or head managers) was collected through the on-site survey (90% confidence level (Z-score: 1.65) and 10.18% tolerance, based on a number of 797 egg-laying farms in 2020). Ethical conflicts on the farms were categorized into three different types according to the hen farm's ethical awareness level: passive, moderate, and active. Additionally, we investigated the correlation between compliance with regulations and ethical consideration. This study confirmed that compliance with animal welfare-related regulations significantly correlated to the level of ethical consideration of farm operators. Interestingly, we also observed that farm operators did not comply with the regulation despite their high level of awareness of animal welfare. This conflict implies contradiction and unresolved ethical dilemmas. Therefore, this study argues that the policies cause conflict in the field despite the certain level of effectiveness on animal welfare regulations.