본 연구는 중국 귀주성과 광서장족자치구 생태박물관의 설립과 운영 주체, 구성 방식 등을 비교 분석한 연구다. 본 연구에서는 우선 중국 생 태박물관이 일반적으로 서양에서 통용되는 에코뮤지엄과 어떤 유사성과 차별성이 있는지, 특히 그것이 국내 지방자치단체가 주도하는 에코뮤지 엄의 조성과 운영에 어떤 시사점과 방향성을 가져오는지를 모색했다. 이 어서 본 연구는 현장 방문을 통한 실증연구로서 중국 중앙정부 차원에서 노르웨이와의 국제 협력사업으로 조성한 귀주성의 생태박물관군(群)과 광 서장족자치구 지방정부가 주도하여 연합체 방식으로 조성한 민족생태박 물관을 중심으로 살펴보았다. 이러한 비교연구에서 두 생태박물관은 영역 을 광역 자치단체로 한다는 점, 광역 안에 분산, 설립되었다는 점, 정부 주도 박 물관이라는 점 등에서는 공통점이 있으나, 조성 주체와 관리 운영 방식 등에 있 어서는 차별성이 분명 존재한다. 이처럼 두 박물관은 조성 배경과 형태, 관리와 운영의 측면에서는 서양과 비교해 매우 이질적이라는 문제와 한계를 갖고 있지 만, 그러한 태생적 이질성을 극복하는 방법은 주민이 중심에 서야 한다는 것이 다. 이는 국내의 광역자치단체가 조성해왔고, 현재도 진행 중인 에코뮤지엄 개발 에도 많은 시사점을 제공한다.

Boron carbide (B4C) is highly significant in the production of lightweight protective materials when added to aluminum owing to its exceptional mechanical properties. In this study, a method for fabricating Al-B4C composites using high-energy ball milling and directed energy deposition (DED) is presented. Al-4 wt.% B4C composites were fabricated under 21 different laser conditions to analyze the microstructure and mechanical properties at different values of laser power and scan speeds. The composites fabricated at a laser power of 600 W and the same scan speed exhibited the highest hardness and generated the fewest pores. In contrast, the composites fabricated at a laser power of 1000 W exhibited the lowest hardness and generated a significant number of large pores. This can be explained by the influence of the microstructure on the energy density at different values of laser power.

Fish samples were collected by a set net from April to December 2020 at the coastal waters off Tongyeong, Korea to determine fish species composition and seasonal variation. A total of 330,675 fish (1,032,578 g) representing 56 species belonging to 39 families were collected during the sampling period. The dominant species were Engraulis japonicus, Trachurus japonicus and Trichiurus japonicus, which accounted for 98.1% of the total number of individuals and 87.5% of the total biomass collected. E. japonicus and Chelidonichthys spinosus appeared every month off the coast of the Tongyeong. Cluster analysis based on the number of individuals of fish were classified into two groups at the dissimilarity level of 57%, and the results of ANOSIM analysis revealed significant differences in community structure among the two groups

This study investigated the rocking behavior of unreinforced masonry walls and wall piers under cyclic loading. Based on the benchmark tests, the characteristics of load-deformation relations in masonry walls with rocking failure were captured, focusing on observed deformation modes. The rocking strengths of masonry walls (i.e., peak and residual strengths) were evaluated, and the effects of opening configurations on the masonry wall strength were examined. The deformation capacity of the rocking behavior and the hysteresis shape of the load-deformation relations were also identified. Based on the results, modeling approaches for the rocking behavior of masonry walls were discussed.

The purpose of this study was to conduct a comparative study between Korea and the United States to examine anglers’ motivations, consumptive orientation, and the relationship between these two concepts. The following two research questions were explored: (1) whether there are significant differences in anglers’ motivations and consumptive orientation between Korea and the United States; and (2) what differences exist in the effects of anglers’ motivations on consumptive orientation between these two countries. The main research results are as follows. First, Korean anglers showed a higher level of consumptive orientation than American anglers. Second, a positive relationship between activity-general motivation and consumptive orientation was reported for Korean anglers while the relationship was opposite for American anglers. Study results imply that national angler surveys as well as public education and outreach programs are necessary to help anglers engage in sustainable fishing behaviors for effective fishery resources management.

This study investigates the interfacial reaction between powder-metallurgy high-entropy alloys (HEAs) and cast aluminum. HEA pellets are produced by the spark plasma sintering of Al0.5CoCrCu0.5FeNi HEA powder. These sintered pellets are then placed in molten Al, and the phases formed at the interface between the HEA pellets and cast Al are analyzed. First, Kirkendall voids are observed due to the difference in the diffusion rates between the liquid Al and solid HEA phases. In addition, although Co, Fe, and Ni atoms, which have low mixing enthalpies with Al, diffuse toward Al, Cu atoms, which have a high mixing enthalpy with Al, tend to form Al–Cu intermetallic compounds. These results provide guidelines for designing Al matrix composites containing high-entropy phases.

연구에서는 한국 시민들의 지진 재해 준비도를 알아보기 위해 지진에 대한 지식, 인지, 대처의 3개 구인으로 구성된 설문 문항을 개발하고 비례 층화 표본 추출 방법으로 수집된 1,256명 시민의 응답을 라쉬분석, 추리통계, 군집 분석 기법을 이용하여 분석하였다. 연구 결과는 다음과 같다: 첫째, 시민들의 지진 재해 준비도 분석 결과, 전체적으로 시민들의 지진 재해 준비도는 ‘보통’ 수준이었으며, 지식과 인지에 비해 대처가 상대적으로 낮은 것으로 나타났다. 둘째, 지진 재해 준비도와 관련된 변인 분석 결과, 지진 재해 준비도에 영향을 주는 변인으로는 성별, 교육 수준, 실제 거리, 안전 인식이 있었다. 셋째, 지진 재해 준비도의 3개 구인 간 상관관계를 분석한 결과, 지식, 인지, 대처 세 가지 구인은 높은 상관을 나타내 구조적으로 서로 밀접한 관계를 보였다. 또한, 성별과 교육 수준이 달라도 이러한 구조적 상관은 비슷하게 나타났다. 군집 분석 결과, 5개 유형의 집단으로 구분되었으며 지진 재해 준비도 3개 구인의 수준이 중간 정 도로 서로 비슷한 집단 유형이 대부분을 차지하였다. 이 연구 결과를 토대로 시민들의 지진 재해 준비도 함양을 위한 교육의 지향점을 제안하였다.

Porous Cu-14 wt% Co with aligned pores is produced by a freeze drying and sintering process. Unidirectional freezing of camphene slurry with CuO-Co3O4 powders is conducted, and pores in the frozen specimens are generated by sublimation of the camphene crystals. The dried bodies are hydrogen-reduced at 500oC and sintered at 800oC for 1 h. The reduction behavior of the CuO-Co3O4 powder mixture is analyzed using a temperature-programmed reduction method in an Ar-10% H2 atmosphere. The sintered bodies show large and aligned parallel pores in the camphene growth direction. In addition, small pores are distributed around the internal walls of the large pores. The size and fraction of the pores decrease as the amount of solid powder added to the slurry increases. The change in pore characteristics according to the amount of the mixed powder is interpreted to be due to the rearrangement and accumulation behavior of the solid particles in the freezing process of the slurry.

본 연구의 목적은 총요소생산성(TFP)을 성과지표로 사용하여 중소기업에 대한 정부지원 R&D사업을 평가하는 것이다. 총요소생산성을 산출하기 위한 분석 모형은 내생성 문제를 완화한 Levinsohn and Petrin (2003) 방법론이며 분석 자료는 2011년부터 2018년까지 기업회계정보이다. 구체적으로 기업회계정보 자료에 국가과학기술지식정보서비스 내 정부지원 R&D사업의 수혜기업 정보를 연계한 후, 성향매칭과 이중차분법을 이용하여 그 성과를 측정하였다. 실증분석 결과는 크게 4 가지이다. 첫째 생산함수 추정결과, 부가가치 창출 측면 에서 총요소생산성의 중요성이 더욱 높아졌다. 둘째 대기업과 중소기업간 총요소생산성 격 차는 여전히 확대되고 있다(2011년도 3.72배에서 2018년 5.23배). 셋째 정부지원 R&D사업에 참여하는 중소기업의 총요소생산성은 미수혜 기업에 비해서는 높은 수준이지만, 지원 사업 전까지 전반적인 하락 추세에 있다가 지원 사업 후 상향 추세로 반전되었다. 넷째 지원 사업 후 1년차 수혜 기업의 총요소생산성의 증가폭은 미수혜 기업군보다 크게 나타났으나 성향매 칭을 통해 설정한 대조군에 비해서는 작았다. 정부지원 R&D사업에 참여하기 전까지 수혜기 업의 총요소생산성이 하락 추세를 나타내는 실증 분석 결과를 고려할 때 중소기업의 R&D지 원에 대한 수요와 정부의 정책목적 사이에 근본적인 차이가 있는지 검토가 필요할 것으로 판 단된다. 또한 중소기업 정부지원 R&D사업이 단순 시혜라는 인식에서 벗어나기 위해서는 보 다 정밀한 제도설계가 필요할 것으로 보인다.

CFRP materials are one of the excellent lightweight materials of the next generation. Also, the CFRP materials are attracting materials form the global automotive industry. However, CFRP material is made at a high cost of carbon fiber as raw material, so research of production cost reduction into the development of molding equipment and molding process technology related to mass production for the automotive industry is actively administered. Generally, CFRP is known as a high corrosion-resistant material in which no corrosion occurs. However, the investigation of the relationship with corrosion behavior on the roughness of CFRP's conditions according to is rarely studied. In this paper, the surface roughness has conducted three surface roughness conditions given arbitrarily, and the electrochemical evaluation has performed under the electrolysis conditions of 5 wt.% NaCl, which is the salt-water test condition of vehicle parts in automotive industries. Moreover, the samples were analyzed with changes of microstructures by FE-SEM and chemical composition's variation by EDS before and after electrochemical evaluation.

The hydrogen reduction behavior of the CuO-Co3O4 powder mixture for the synthesis of the homogeneous Cu-15at%Co composite powder has been investigated. The composite powder is prepared by ball milling the oxide powders, followed by a hydrogen reduction process. The reduction behavior of the ball-milled powder mixture is analyzed by X-ray diffraction (XRD) and temperature-programmed reduction at different heating rates in an Ar-10%H2 atmosphere. The scanning electron microscopy and XRD results reveal that the hydrogen-reduced powder mixture is composed of fine agglomerates of nanosized Cu and Co particles. The hydrogen reduction kinetics is studied by determining the degree of peak shift as a function of the heating rate. The activation energies for the reduction of the oxide powders estimated from the slopes of the Kissinger plots are 58.1 kJ/mol and 65.8 kJ/mol, depending on the reduction reaction: CuO to Cu and Co3O4 to Co, respectively. The measured temperature and activation energy for the reduction of Co3O4 are explained on the basis of the effect of pre-reduced Cu particles.

Recreation specialization and consumptive orientation are two important constructs to understand anglers’ attitudes and behaviors. Although theoretical explanations and previous studies in different countries addressed the relationships between the two constructs, limited support has been provided in a context of anglers in Korea. This study developed a conceptual model explaining the causal relationships between recreation specialization, anglers’ preferences (activity-specific and activity-general) and consumptive orientation. An on-site survey was conducted to anglers in the city of Busan and Gyeongnam province in 2018. A total of 614 data were analyzed using Structural Equation Modeling The study results showed that recreation specialization positively and indirectly influenced consumptive orientation via anglers’ activity-specific and activity-general preferences. Theoretical and practical implications are further discussed.

Aluminum alloys are the light weight materials, they are commonly used in many industrial applications such as electronic, aerospace, automotive, and medical industry. Because they are used in these such applications. Therefore, their light weight and high surface quality are required. In this paper, the surface improvement round flat aluminum alloy using lapping finishing method was explored. In order to find the optimal condition, lapping parameters such as, rotational speeds, abrasive grain sizes of pad, processing times, and lapping oils were investigated in this study. The improvement in surface roughness was found to be highest with optimal condition at 200 rpm of rotational speed, 1 ㎛ abrasive grain size of pad, 0.5ml of light oil for 720 sec. By using the optimal condition, the initial surface roughness Ra of round flat aluminum alloy can be enhanced from 2.59㎛ to 0.02 ㎛. This can be concluded that the small CNC machine with lapping finishing method can be used to enhance the surface roughness of round flat aluminum alloy effectively.

Magnetic abrasive finishing (MAF) process is a surface improvement method, which the magnetic field of permanent magnet or electromagnet is used to control the abrasive particles during the finishing process. The magnetic abrasive tools are filled between the N-pole and S-pole of Nd-Fe-B type permanent magnets. Tungsten carbide bar (WC) is a high hardness material and its compressive strength is much higher than the other materials. Therefore, due to its superior mechanical properties, it has been widely used in cutting or machining process. Because the smooth surface of tungsten carbide is required in cutting tools, thus the magnetic abrasive finishing process was applied for achieving its surface accuracy and dimensional accuracy. The results showed that the surface roughness of tungsten carbide bar was improved from Ra: 0.23㎛ to Ra: 0.02㎛ in 120 sec by magnetic abrasive finishing process.