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        검색결과 142

        1.
        2024.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The current survey form of grassland has not played its role in managing the grassland effectively because of the ambiguous questionnaire items and the absence of method and time of the investigation. Therefore, this study was conducted to clarify and add the items for effective of grassland management. The survey form of grassland was regulated in Article 16 of the Enforcement Rules of the Grassland Act (Survey on Grasslands Management Status, etc.). The five contents that needed improvement were the grassland owner, the survey timing and method of established grassland, grassland used livestock, grassland usage condition, and grassland grade. In the improved survey form of grassland, the grassland owner was changed to the grassland manager. In addition, ‘Survey by each land’ was added to the improved survey form in which the managers can survey each land. The dimension of each grassland establishment method was deleted in the grassland establishment time and method. In the livestock using grassland, the number of livestock and the area where livestock are used were added, and the number of other livestock was added, too. The grassland grade was decided as the combined score by three evaluation categories; grassland usage, the ratio of forage production in grassland and kinds of forage. The high, middle, and low grades were over 8, 6~7, and under 5 points in the combined score, respectively. The results show that the changed survey form of grassland can make grassland management more efficient by materializing the subject of grassland management and the survey terminology and methods.
        4,000원
        2.
        2024.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 논문에서는 컨테이너선의 선형 최적 설계 자동화와 관련하여 연구한 내용과 결과를 정리하였다. 컨테이너선은 일반적으로 프루우드 수 0.26 근처에서 운항하는 선박으로 이 속도에서 운항하는 선박 전용 선형 최적 설계 자동화를 구현하기 위하여 최적화 알고리 즘, 선형 변경 알고리즘, 선박 성능 예측 알고리즘, 자동화 알고리즘 그리고 반복적 계산 기법을 적용하여 컨테이너선의 선형 최적 설계 자동화가 가능한 수치해석 컴퓨터 프로그램을 개발하였으며, HOTCONTAINER라고 명명하였다. 본 연구에서는 선형 최적 설계를 위한 설 계 변수의 적절한 선정을 위하여 민감도 분석 알고리즘을 개발하여 적용하였다. 개발된 선형 최적 설계 자동화 알고리즘의 신뢰성과 실 선 적용성을 파악하기 위하여 세계적으로 다양한 연구가 진행된 컨테이너 선박인 KCS 선박을 대상 선박으로 하여 선형 최적 설계 자동 화 수치해석을 수행하여 그 결과물로써 최적 선박을 도출하고, 대상 선박과 최적 선박의 조파저항과 파계 그리고 파고를 비교하였다. 결 론적으로 최적 선박이 대상 선박과 비교하여 조파저항이 47.63% 감소한 것을 볼 수 있었으며, 배수량과 접수 표면적은 각각 0.50%, 0.39% 감소한 것을 볼 수 있었다.
        4,000원
        3.
        2024.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 연구에서는 너클 라인이 다수 존재하면서 안팎 형상이 비대칭으로 설계된 특이점을 갖는 쌍동선의 자항성능을 예측하기 위 해 CFD 해석을 수행하였고, 해석 기법에 따른 차이를 파악하기 위해 MRF(Moving Reference Frame) 기법과 SDM(Sliding Mesh) 기법을 적용하 였다. MRF 기법을 적용한 경우에는 time step당 프로펠러를 1˚ 회전시켰고, SDM 기법의 경우 10˚, 5˚, 1˚씩 회전시키며 각 기법별 예측된 자 항성능을 비교하였다. 자항점 추정을 위한 몇 가지 프로펠러 회전수에서의 해석 결과 중 프로펠러의 토크는 기법에 따른 차이가 거의 없었 지만 추력 및 선체가 받는 저항은 MRF 기법보다는 SDM 기법을 적용했을 때 더 낮게, SDM 기법의 time step당 프로펠러 회전각이 작을수 록 높게 계산되었다. 선형 내삽을 통해 추정된 자항점의 프로펠러 회전수, 추력, 토크와 실선 확장법을 사용해 추정된 실선의 전달동력, 반 류 계수, 추력 감소 계수 및 프로펠러 회전수도 동일한 경향을 보였으며, 대부분의 자항효율은 반대의 경향을 보였다. 프로펠러 후류의 경 우 MRF 기법을 적용했을 때 정확도가 떨어졌고, SDM 기법의 time step당 프로펠러 회전각에 따라 표현되는 후류의 차이는 거의 없었다.
        4,000원
        4.
        2024.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Jinhae is the oldest Western-style radial and grid city on the Korean Peninsula, and it also has the most defined structure to date, remaining largely unchanged and unlike any other in Korea. The Jinhae town plan was completed immediately after the signing of the Japan-Korea Treaty. Although the city of Jinhae was built by the Japanese, its overall organizational principle is clearly a radial-grid form that was established in the West. The Jinhae radial-grid planning was elaborately constructed with multiple layers of overlapping structures. It is the result of the application of geometry that creates symmetry and hierarchy in European countries, and the simultaneous consideration of road hierarchy and land form in the process of combining radial and grid forms. To reveal these points, four analyses are performed. First, the formation process of Western radial and grid streets is reviewed and compared to derive review points for Jinhae City. Second, the layout and geometric characteristics of radial streets are discussed. Third, the hierarchical characteristics and connections of grid streets are analyzed. The last part is a comparative analysis of the plan and the final realization.
        4,500원
        5.
        2023.12 구독 인증기관 무료, 개인회원 유료
        한자가 중국에서 한국으로 전래된 후 한자의 학습과 사용을 편리하게 하기 위해 한자교육 방면의 동몽 독서물이 대량으로 정리되고 편찬되었다. 󰡔한국유학교육자료집해󰡕 제1권 󰡔동몽교 육편󰡕은 조선시대에 간행된 19종의 동몽 독본을 수록하여 조선시대 민중의 한자에 대한 인식과 문자 사용 실태를 전반적으로 이해하는 데 귀중한 자료를 제공한다. 19종의 한자 동몽 자료는 많은 이체 속자를 사용하여 중국의 한자 사용과 다른 특징을 보여준다. 총체적으로 볼 때 조선시 대 동몽 문헌에 보이는 속자는 크게 두 가지 유형이 있다. 하나는 필획의 증감, 필획의 형태 변화, 간접 부건과 기타 부건의 혼재, 부건 배치의 차이, 초서의 해서화 등의 요인으로 형성된 異寫俗字이고, 다른 하나는 조자 방법의 차이, 조자 방법은 같지만 부건이 다른 경우, 구조적 속성은 같지만 부건 수량이 다르거나 필사의 변이로 인한 구조의 차이 등의 요인으로 형성된 異構俗字이다. 조선시대 동몽 문헌의 속자 사용에서도 주목할 만한 특징이 나타난다. 예컨대 고문과 예서의 정서법을 많이 보존하고 있고, 중국 고대 속자의 변형된 정서법을 전승 및 사용하 고 있으며, 문자의 속자가 체계성을 갖추고 있는 등을 들 수 있다.
        8,400원
        7.
        2023.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        In this study, gold nanoparticles (AuNPs) were synthesised using green chemistry to decorate multi-walled carbon nanotubes (MWCNTs) made from walnut shells transmission electron microscopy, field-emission scanning electron microscopy (FESEM), atomic force microscopy and fourier transforms infrared spectroscopy were used to diagnose MWCNTs and AuNPs. MWCNT-COOAu, MWCNT-COO and MWCNT-Au were diagnosed by Raman, energy dispersive X-ray analysis and FESEM. The effect of AuNPs, MWCNT-COO, MWCNT-COOAu and MWCNT-Au on pure and serum alkaline phosphatase (ALP) enzyme activity was studied in vitro using the enzyme-substrate 4-nitrophenyl disodium orthophosphate. For pure enzymes, Vmax slightly increased as the concentration of MWCNT-Au, MWCNT-COOAu and MWCNTCOO increased, whereas the Vmax values decreased as the concentration of AuNPs increased. The inhibition type for all NPs varied. For serum ALP enzyme, the Vmax values for Au-based NPs decreased as the concentration of NPs increased. The Vmax values exceeded the standard value at the concentrations of 25, 50 and 75 ppm for MWCNT-Au and MWCNT-COOAu, whereas the Vmax values increased over the standard value for all concentrations of AuNPs.
        4,500원
        8.
        2023.05 구독 인증기관·개인회원 무료
        Radioactive waste generated in various forms needs to be technically stabilized for safe treatment, disposal, and long-term safety. Overseas, research on vitrification with excellent mechanical and physicochemical properties of high-level waste is being actively conducted. Vitrification is a process of converting radioactive waste into a stable and durable glass-like material, which is then safe storage and disposal. The stability of vitrified form is an important concern for environment safety, as any leakage or release of radionuclide could have serious consequences for health and the environment. Therefore, several studies are being conducted on the disposal stability of vitrification of radioactive waste. In order to evaluate the stability of the solidified form, mechanical properties such as density, microhardness, and compressive strength and chemical durability such as leaching properties should be performed. There are several types of leaching test methods to evaluate the chemical durability, which is important in the characterization of solidified forms. In this study, the leaching test method for chemical durability evaluation and the evaluation results of leaching characteristics according to pH were reviewed.
        9.
        2023.04 KCI 등재 구독 인증기관 무료, 개인회원 유료
        To transform old words into new words is a very efficient mode of word derivation in contemporary Chinese, which mainly involves the transformation of word form and the transformation of meaning. In the process of transforming the old words language users have created a lot of new words that are very novel in form or meaning based on the relationship between Chinese characters in terms of sound, shape and meaning or the structural features of Chinese characters. This paper lists more than 130 new appellations including sound-based words, form-based words, meaning-based words and words produced by changing the structure of Chinese characters, names the ways how old words transform into new words as JieYinFuXing, XieYinFuYi, BieJieFuYi, FanBeiFuYi, GaiZiBianXing and describes the transformation process of these words. These lexical phenomenons reflect some language psychology such as pursuing new differences, playing jokes and mental association. They have some impacts on the lexical system of contemporary Chinese as they open up new ways for the generation and change of contemporary Chinese words, they supplement the word-making methods and lead to some unconventional combinations in contemporary Chinese lexis. This paper intends to further clarify the important role of Chinese characters in word creation and word development, and deepen the understanding of Chinese Character study and contemporary Chinese lexicology.
        5,800원
        10.
        2023.04 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This article focuses on the Namdaemum repair and the Seokguram restoration, which had begun in 1961, as an important repair conducted during the time of seeking the conservation principle of architectural heritage after liberation in Korea. Through the analysis of the principles described in the repair report issued after the two repairs, meeting records, and related expert announcements, it is shown that the principle of 'preservation of the historic state' had been established at Namdaemun repair and later have changed to the principle of 'restoration of the historic form' which means reconstruction in Seokguram restoration. By analyzing the minutes of the Cultural Heritage Committee's meeting on the repair of other cultural properties during this period, it is revealed that the key terms related to the preservation principle, 'historic form' and 'restoration', were given meaning as 'object' and 'method' of preservation, and then 'restoration of the historic form' has been gradually used as a conservation principle.
        4,500원
        12.
        2022.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The tombs at the royal level of the Western Han dynasties belong to the five kingdoms of Chu, Liang, Lu, Zhongshan and Changyi, representing the new forms and ideas of the tomb architecture. Taking Shanchuwang Tomb in BeidongShan, Xuzhou as an example, this paper analyzes the architectural structure and symbolic significance of the tomb, and tries to discuss the concept of burial reflected in it.The analysis of the structure of the main body of the tomb reveals the basic logic of the tomb imitating the palace on the ground, and the definition of the nature of the annex reflects its transcendence over the general form of the tomb.
        4,500원
        13.
        2022.10 구독 인증기관·개인회원 무료
        The disposal criteria of the domestic LILW disposal facility specifies that fluidized substances such as the spent resin, the evaporator bottom should be solidified in a physically stable solid form, such as cementation and polymerization. And the solidified form applies requirements for compressive strength, immersion test, thermal circulation test, radiation irradiation test, leaching test, and free standing water measurement test. On the other hand, it is specified that immobilization iss applied to wastes with a total radioactivity concentration of more than 74,000 of radionuclides with a half-life exceeding 20 years among non-homogeneous wastes such as spent filters and DAW, but the test requirements are not applied. Nevertheless, it is necessary for waste generator to establish quality control standards for the manufacture of immobilized solid form through reviewing overseas cases and domestic regulations and technical standards. The test requirements for solidified solid form require measurement of structural stability (compressive strength, immersion, thermal cycling, irradiation test), leachability (leaching test), and free standing water measurement. A characteristic of the immobilized solid form is that it is not mixed with the waste and that the cement medium surrounds the waste. Therefore, the structural soundness is higher than that of the solidified solid mixed with waste. In addition, even when in contact with water, the cement medium blocks the contact between waste and water, thereby preventing the spread of radionuclides. Therefore, considering the characteristics of these immobilized solid form, compressive strength test and free standing water measurement are applied for structural soundness. For other tests, it is determined that application is unnecessary.
        14.
        2022.05 구독 인증기관·개인회원 무료
        Radioactive materials emitted from nuclear accident or decommissioning cause soil contamination over wide areas. In the event of such a wide area of contaminated soil, decontamination is inevitable for residents to reside and reuse as industrial land. There are many ways to decontaminate these contaminated soils, but in urgent situations, the soil washing, which has a short process period and relatively high decontamination efficiency, is considered the most suitable. However, the soil washing process of removing fine soil and cesium by using washing liquid as water and adding a flocculating agent (J-AF) generates slurry/sludge-type secondary waste (Cs-contaminated soil + flocculating agent). Since this form of sludge contaminants cannot be disposed, solidification is needed using an appropriate solidification agent to treat wastes for disposal. Therefore, this study devised a treatment method of contaminated fine soils occurring after the soil washing process. This investigation prepared the simulated wastes of contaminated fine soils generated after the soil washing, and pelletized the samples using a roll compactor under the optimum operating conditions. The optimum conditions of the device were determined in the pre-test. Roll speed, feeding rate, and hydraulic pressure were 1.5 rpm, 25 rpm, and 28.44 MPa, respectively. The waste forms were manufactured by incorporating created pellets (H 6.5 × W 9.4 mm) using polymers as solidification agents. Used polymers were main ingredient (YD-128), hardener (G-1034), and diluent (LGE). The optimum mixing ratio was YD-128 : G-1034 = 65 : 35 phr, and LGE was added in an amount of 10wt% of the total mixture. To confirm the disposal suitability of the manufactured waste forms, characterization evaluation was carried out (compressive strength, thermal cycling, immersion, and leaching test). Characterization evaluation revealed a minimum compressive strength of 23.1 MPa, far exceeding 3.44 MPa of the disposal facility waste acceptance criteria. Compressive strength increased to the highest value of 31.90 MPa after immersion test. To examine leaching characteristics, the pH, Electrical Conductivity (EC) and leachability index (􀜮􀯜) of leachates were identified. As results, pH and EC consistently increased or remained constant with leaching time. The average of Co, Cs and Sr nuclides was 17.76, 17.38 and 14.04, respectively, exceeding the value of 6 in the waste acceptance criteria. Effective waste treatment/ disposal can be achieved without increasing volumes of sludge/slurry by enhancing the technique of this research by performing additional studies in the future.
        15.
        2022.05 구독 인증기관·개인회원 무료
        During the treatment of spent nuclear fuel, radioactive iodine is generated in a liquefied or gaseous form in a specific process. In the case of iodine 129, it is a long-lived nuclide with a very long halflife and has high groundwater mobility under repository conditions. Despite showing a low radioactivity value, research on the management of radioactive iodine from a long-term perspective is continuously being performed. Although research has been conducted using borosilicate glass as a medium for solidifying iodine, compatibility of I in borosilicate glass is very small and the volatility is high in the solidification process. So it is not suitable as a solidified substance of iodine. Therefore, studies on other solidification media to replace them are continuously being conducted. Our research team tried to develop a new medium that can contain iodine in a solidified body stably through a simple heat treatment process and can improve problems such as volatility and waste loading. Iodine is captured as AgI in the Ag ion-exchanged zeolite. So, TeO2, Ag2O, and Bi2O3 having a high AgI loading rate were used as main components. It was named TAB after taking the first letter of each element. In previous studies, the physical properties, structure, and chemical stability of TAB materials were confirmed. PCT (Product Consistent test) was performed to confirm chemical stability. It is mainly used to compare the chemical stability of glass materials with other glass materials, but there are limitations in evaluating the long-term chemical stability of materials. In this experiment, we tried to evaluate the long-term stability of TAB and compare it with borosilicate, which is conventionally used to treat radioactive waste. In addition, we tried to understand the leaching behavior inside the TAB medium. For this purpose, ASTM C1308 test was performed for 365 days, and distilled water and KURT groundwater were used as leachates to examine the effect of ions in the groundwater on the solidified body. To analyze the leaching behavior, ICP-MS and ICP-OES analyses were performed, and the cross-section of the sample after leaching was observed through SEM.
        16.
        2022.03 KCI 등재 구독 인증기관·개인회원 무료
        빅 데이터, 알고리즘, 인공지능, 블록체인, 메타버스 및 스마트계약과 같이 21세기의 기술혁신은 기존의 주주총회 개최방법의 효율성과 공정성 에 의문을 제기하게 만들었고, 경영진에게 새로운 역량이나 기술을 습득 하거나 보유할 것을 요구하고 있으며, 기업 내에서 기존에 의사결정을 내리던 자들에게 보다 효율적인 방식으로 기업을 운영할 수 있는 도구를 제공하고, 기업 내에서 누가 실질적인 의사결정권을 가져야 하는지를 결 정하는 균형추를 바꾸어 놓고 있으며, Corona-19 팬데믹은 가상주주총 회 도입 시기를 우리가 예상했던 것보다 훨씬 더 빠르게 앞당겨 놓았다. 기업지배구조의 기본 테마 중 하나는 기업의 경영진에게 부여되는 광 범위한 재량권과 주주들이 경영진에 대해 책임을 추궁할 수 있는 권한 간에 균형을 맞추는 일이다. 따라서 이글은 새로운 기술들이 어떻게 주 주총회를 주주민주주의의 시금석으로 부활시키고, 어떻게 주주들이 기업 경영에 관여할 수 있는 새로운 길을 열 수 있는지, 기업 내 구성원들의 역할 및 권한과 책임분배에서 어떤 역할을 수행할 수 있는지, 공동의사 결정 비용을 감소시키고 보다 효율적인 의결권 행사절차를 가능케 함으 로써 주주총회의 역할을 강화시킬 수 있는지 등에 대한 것들이다. 그런 데 가상주주총회에 대해 비판적 견해도 많지만 가상주주총회는 주주참여 와 접근성을 높이고, 주주와 이사 및 경영진 간의 상호작용을 활발하게 하며, 탄소 발자국을 줄일 수 있고, 비용을 절감할 수 있는 등 많은 장점 을 가지고 있다, 특히 개인투자자들이 적극적으로 주주총회에 참석하여 건설적인 의견을 제시할 경우, 효율적인 의사결정이 이루어질 수 있고, 이는 회사의 실적향상으로 이어질 수도 있으므로 형해화 되었다는 비판 을 받던 주주총회가 본연의 기능을 회복할 수 있을 것이라는 기대는 가 상주주총회가 갖는 최고의 장점이 아닐까 하는 생각이 든다. 그러나 이 제도가 우리나라에 온전하게 도입되기 위해서는 학계의 비 판적 견해와 갈라져 있는 견해들을 수렴하여 바람직한 해결책을 찾고, 특히 우리보다 앞서 많은 논의가 이루어지고 실무경험이 풍부한 외국의 사례들을 심도 있게 연구하여 바람직한 기업지배구조 개선을 위한 입법 방향을 제시할 수 있어야 할 것이다. 그리고 주식회사 구성원들 간에 보 다 활발한 상호작용이 이루어질 수 있는 메타버스 기술과 의결권 행사 데이터에 대한 위조와 변조가 현실적으로 어려워 보안성이 높기 때문에 의결권 행사의 신뢰성을 확보할 수 있는 블록체인 기술도 아울러 도입할 것을 제안한다.
        17.
        2021.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        전자 및 화학 산업의 초순수 생산 및 원자력 발전소의 부식 제어를 위해 이온교환 수지탑의 성능 파악이 필수적이다. 따라서 본 연구에서는 4종의 H 및 ETAH 형 양이온 교환수지가 채워진 양이온 및 혼상 이온교환수지탑에 미량의 NaCl를 포함하는 에탄올아민(ETA) 및 암모니아(NH3) 용액을 주입하여 양이온 파과특성을 조사하였다. 조사 결과, 주성분인 ETAH+ 및 NH4 +와 달리, 미량성분인 Na+는 (이론적교환용량의 3배 이상) 시험기간 동안 수지탑 출구에서 파과 및 오버슈팅 현상이 나타나지 않았다. H형 수지탑의 파과현상은 ETAH+ 및 NH4 +가 순서대로 일어났고, 오버슈팅은 NH4 +가 파과할때 ETAH+에 대해서 발생했다. 파과영역의 너비로 결정되는 상대적 선택도는 NH4 +가 ETAH+보다 최대 51.5 % 더 높았다. 유입수 Na+ 농도가 높을수록, 선택도는 감소하고 오버슈팅 현상은 증가하였다. 이온교환 수지의 고유 특성을 개선하여 감소시킬 수 있는 Na+ 누출은, ETAH형에서 높았고 4종의 양이온수지에 대해 동일하지 않은 것으로 조사되었다.
        4,300원
        20.
        2021.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The purpose of this study was to develop an optimized hull-form of a coastal fishing vessel operating at high speed. In order to achieve the purpose of the study, HOTBOAT, that can perform an automatic hull-form optimal design of a coastal fishing vessel, was developed. HOTBOAT was composed of an objective function estimation algorithm and an optimization algorithm and a hull-form modification algorithm. In this study, the wave-making resistance was selected as an objective function and the potential-based panel method was applied to predict the objective function. SQP(sequential quadratic programming) method were adopted to predict the optimal direction and answer. Bell-shaped hull-form modification function method and NURBS(non-uniform rational B-spline) geometry modeling method were applied to modify the hull-form during the whole optimization process. HOTBOAT was applied to develop the optimal hull-form of a coastal fishing vessel with minimum wave resistance. The initial hull-form of the coastal fishing vessel was compared with the optimal hull-form. As a result of hull-form optimization, a coastal fishing vessel with a reduction of about 30% was developed compared with the initial hull-form and the displacement and the wetted surface area of the optimal hull-form was decreased to less than about 1% in comparison with the initial hull-form.
        4,000원
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