• Journal of the Institute of Convergence Signal Processing
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• v.21 no.1
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• pp.13-20
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• 2020

In shipyards, internal materials are assembled after designing and manufacturing each ship's block. Internal material assembly means the installation of parts and equipment except ship's body. In this process, if the assembly of pipes and equipment existing in the block is not done correctly during the assembly between blocks, this causes a lot of costs. In addition, even if the assembly of the internal materials already completed, the production efficiency of the ship is reduced due to rework when problems such as space arrangement of the internal materials occurs. Therefore, this study introduces space arrangement and inspection system before and after hull outfitting work based on coexistence reality technology using 3D design drawing to solve these problems. The various coexistence reality algorithms and inspection systems developed and introduced in this study are based on AR service, which has never been introduced in Korea. So it will be widely applicable to various manufacturing industries using design drawings such as automobiles and architectures as well as ship building process.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.22 no.1
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• pp.409-414
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• 2021

Tightness performance that blocks compartments is important for surface ships to achieve superior mission performance and survivability in combat environments. To meet the above requirements, airtightness of the structural elements and the appropriate strength to specific areas are checked during a test run after ship construction. In particular, air tests of compartments adjacent to the water surface are performed. In an air test, air is injected into the compartment up to the test pressure of the test memo. The pressure drop value is checked after 10 minutes to determine if the requirements of the corresponding area are satisfied. In summer, however, when the influence of the outside temperature is large, a phenomenon in which the internal pressure increases during the air test was identified. This phenomenon reduces the reliability of the test result. Therefore, a system was designed to compensate for temperature changes in the compartments through this study. The developed system calculates the amount of pressure change caused by a temperature change in the compartment and outputs a correction value. The pressure change was calculated using the ideal gas equation, reflecting the maintenance, increase, and decrease in temperature during the test process. A comparison of the calculated pressure correction value with the database of NIST REFPROP revealed a difference of 0.126% to a maximum of 0.253%.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.32 no.3
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• pp.89-95
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• 2022

In this study, glassy carbon coating was performed on the graphite using a phenolic resin and a curing agent was mixed with ethylene glycol as an additive to form the uniform surface. The phenolic resin was dried and cured under the environments of hot air, then converted into a glassy carbon layer by pyrolysis at 500~1,500℃. FTIR, XRD, SEM analysis, and density/porosity/contact angle measurement were performed for characterization of glassy carbon. The pyrolysis temperature for high-quality glassy carbon was optimized to be about 1,000℃. As the content of the additive increased, the effect of reducing surface defects on the coated surface, reduction of porosity, increase of contact angle, and increase of density were investigated in this study. The method of forming a glassy carbon coating layer through an additive is expected to be applicable to graphite coating and other fields.

• Journal of Aerospace System Engineering
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• v.16 no.1
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• pp.56-69
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• 2022

Various advanced countries are accelerating the competition in the development of hypersonic weapons. North Korea is on the verge of building a new submarine equipped with a submarine-launched ballistic missile (SLBM). A series of new guided missiles tests have continued due to political competition between the U.S. and China. The Republic of Korea is planning to boost its military capabilities, which involves the development of nuclear-powered submarines, light aircraft carriers, and new guided missiles. The northeast Asian region continues to be tense amid military rivalry between the Republic of Korea, North Korea, the United States, China, Russia, and Japan. Accordingly, these countries' competition to develop weapons is also at the world's highest level. In this paper, we examine the functioning of a hypersonic weapons system conduct a technical analysis of its components. In addition, we analyze the direction of military development that the Korean military wants to pursue through the recently announced mid-term defense plan. We conclude by highlighting the technical limitations and implementation strategies to overcome the development of hypersonic weapons.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2022.09a
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• pp.81-81
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• 2022

잇꽃(Carthamus tinctorius L.)은 국화과에 속하는 두해살이 초본 식물로 한자명은 홍화(紅花), 영명으로는 Safflower를 사용하고 있다. 우리나라의 잇꽃 재배는 2010년 39ha 수준이 재배되다가 2014년에는 76ha까지 확대되었으나, 점차 감소하는 추세를 보이고 있으며 2020년에는 52ha가 재배되고 있는 것으로 보고되었다. 잇꽃은 종자를 약용으로 이용하거나 꽃잎을 건조하여 천연 염색제 및 향신료로 이용하고 있으나, 일본 산형(山形)현에서는 잇꽃의 경관적 가치를 이용해 홍화 축제를 개최함으로써 소득작목으로 자리매김하고 있다. 본 연구는 지리산을 중심으로 한 준고랭지 지역에서 잇꽃의 경관적 가치의 활용 가능성을 검토하고자, 국립농업유전자원센터로부터 총포에 가시가 없는 무가시형 유전자원(IT323225, IT333473, IT333482)을 분양받아 가시가 있는 재배종과 파종시기별로 개화 특성 등을 비교하였다. 표고 500m 준고랭지의 비가림 하우스에서 3월 하순부터 6월 상순까지 파종시별로 출현율을 검토한 결과, IT 323225 자원은 관행의 3월 하순 파종에서도 40.5%의 낮은 출현율을 보였다. 3월 하순 파종에서 재배종은 6월 22일경에 개화기에 도달하였으나, 무가시형 유전자원들은 7월 2일~5일경에 개화기에 도달하여 만생종의 특성을 보였다. 파종시기를 늦춰 5월 하순에 피종하는 경우 무가시형 자원들은 7월 27일~29일경에 개화기에 도달하였으며, 개화기 전후의 개화 지속기간은 8~10일이 소요되어 3월 하순에 파종하여 7월 상순에 개화하는 경우보다 2~4일이 단축되는 경향이었다. IT333473 자원의 개화기 초장은 5월 하순 파종하는 경우 관행의 3월 하순 파종보다 43.6%가 즐어든 71.1cm를 보였고, 분지수는 41.6% 감소한 8.0개/주 수준을 보였다. 식물체당 착화수 또한 파종시기를 늦춤에 따라 감소하는 경향이었으나 화당 종자수는 IT323225 자원은 5월 중순과 하순 파종시에 증가하는 양상이었고 IT333473 자원과 IT333482 자원은 재배종과 같이 감소하였다. 하계 휴양지로 각광받고 있는 지리산권에서 무가시형 잇꽃 자원의 경관적 가치 활용 가능성을 검토한 결과, 파종시기를 5월 하순으로 늦추는 경우 성수기인 7월 하순과 8월 상순에 개화가 가능하였다. 또한 식물체의 초장이 71.1~83.6cm 수준으로 단축되어 경관 조성에 유리한 특성을 보였다.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2020.12a
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• pp.76-76
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• 2020

최근 안전한 먹거리 생산과 치유, 교육 등 다양한 목적으로 도시농업에 참여하는 인구가 늘어남에 따라 도시텃밭의 농약, 비료 사용 등으로 인한 환경오염과 해충 피해, 농산물의 건강성 등 다양한 문제가 제기되고 있다. 따라서 도시텃밭 작물의 생육 증진, 잔류농약 문제 해결 등 농산물 안정성 증가에 기여하고자 식물추출물을 활용한 엇갈이 배추의 생육특성을 조사하였다. 선행연구 결과를 바탕으로 자원식물류 5종(쇠비름, 소리쟁이, 명아주, 박주가리, 환삼덩굴)과 허브류 5종(메리골드, 서던우드, 캐모마일, 애플민트, 로즈마리), 식용작물류 5종(양파, 마늘, 부추, 차즈기, 들깨) 등 추출 대상 식물 15종을 60℃에서 3일간 건조시켜 마쇄하였다. 이후 각 식물체 100g을 35% 에틸알코올 1,000ml에서 7일간 추출하였다. 추출물은 30%로 희석하여 주 2회씩 총 3주간 배추에 엽면살포하였다. 엽면적, 엽수, 지상부 및 지하부 생체중 등 생육특성을 7일 간격으로 조사하였으며 그 결과는 다음과 같다. 엽면적과 엽폭은 환삼덩굴 처리구에서 104.58cm²와 9.80cm로 가장 넓었고, 엽장은 박주가리 처리구에서 25.24cm로 가장 길었으며, 지하부 생체중은 메리골드 처리구에서 6.24g으로 가장 높았다. 엽수는 애플민트와 마늘 처리구에서 6.4개로 가장 많았고, 지상부 생체중과 엽록소는 집단 간 유의한 차이가 나타나지 않았다. 전반적으로 무처리 대비 엽면적 22%, 엽폭 18%의 유의한 생장 차이를 보인 환삼덩굴 추출물과 엽면적 12%, 엽장 17%의 생장 차이를 보인 박주가리 추출물, 엽면적 10%, 엽폭 9%의 생장 차이를 보인 양파 추출물이 엇갈이 배추 생육에 효과적인 것으로 나타났다. 본 연구결과 환삼덩굴, 박주가리, 양파 등 일부 식물추출물이 엇갈이 배추의 생육을 증진시킬 수 있는 것으로 나타나 주말농장 등 도시텃밭에 활용할 수 있을 것으로 사료되었다. 향후 식물추출물의 효과성을 증진시키기 위해 추출 방법과 적정 농도, 보관 시기 등에 대한 연구와 함께 도시텃밭 해충방제 효과를 알아보기 위한 약해검정과 살충효과를 분석할 필요성이 있다.

• Korean Journal of Heritage: History & Science
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• v.48 no.2
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• pp.142-157
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• 2015

This study examines how traditional knowledge functions in the specific techniques to make pottery in terms of the traditional knowledge on the pottery techniques of Onggi potters. It focuses on how traditional pottery manufacturing skills are categorized and what aspects are observed with regard to the techniques. The pottery manufacturing process is divided into the preparation step of raw material, the molding step of pottery, and the final plasticity step. Each step involves unique traditional knowledge. The preparation step mainly comprises the knowledge on different kinds of mud. The knowledge is about the colors and properties of mud, the information on the regional distribution of quality mud, and the techniques to optimize mud for pottery manufacturing. The molding step mainly involves the structure and shape of spinning wheels, the techniques to accumulate mud, ways to use different kinds of tools, the techniques to dry processed pottery. The plasticity step involves the knowledge on kilns and the scheme to build kilns, the skills to stack pottery inside of the kilns, the knowledge on firewood and efficient ways of wood burning, the discrimination of different kinds of fire and the techniques to stoke the kilns. These different kinds of knowledge may be roughly divided into three categories : the preparation of raw material, molding, and plasticity. They are closely connected with one another, which is because it becomes difficult to manufacture quality pottery even with only one incorrect factor. The contents of knowledge involved in the manufacturing process of pottery focused are mainly about raw material, color, shape, distribution aspect, fusion point, durability, physical property, etc, which are all about science. They are rather obtained through the experimental learning process of apprenticeship, not through the official education. It is not easy to categorize the knowledge involved. Most of the knowledge can be understood in the category of ethnoscience. In terms of the UNESCO world heritage of intangible cultural assets, the knowledge is mainly about 'the knowledge on nature and universe'. Unique knowledge and skills are, however, identified in the molding step. They can be referred to 'body techniques', which unify the physical stance of potters, tools they employ, and the conceived pottery. Potters themselves find it difficult to articulate the knowledge. In case stated, it cannot be easily understood without the experience and knowledge on the field. From the preparation of raw material to the complete products, the techniques and traditional knowledge involved in the process of manufacturing pottery are closely connected, employing numerous categories and levels. Such an aspect can be referred to as a 'techniques chain'. Here the techniques mean not only the scientific techniques but also, in addition to the skills, the knowledge of various techniques and levels including habitual, unconscious behaviors of potters.

• Analytical Science and Technology
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• v.8 no.1
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• pp.91-99
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• 1995

One of alternative conventional technologies used for treatment of livestock wastes is composting process, and recently some mechanical composting processes are being practiced. It is, however, recognized the composting process also has its own limitations such as longer time requirement, and difficulties to estimate the degree of decomposition, etc. The incomplete compost contains potentially harmful materials to crops and public health due to instabilized organic contents and pathogenic organisms. The purpose of this investigation is to develop an innovative system whereby anxious livestock wastes are thoroughly stabilized and disinfected. Thus the overall management scheme should meet the following requirements. 1. A system should be in a cost-effective and environmentally sound manner. 2. Sludges must be chemically stabilized and bacteriologically safe. 3. Odor-free by product should be applied to crop land. 4. Sludges are sources of fertilizer nutrients and/or soil amendments to enhance crop production. 5. And they can be used as potential pH adjusting agent of the acidified soils. Overall effectiveness of the developed system is experimentally tested to satisfy the preset criteria and requirements. Major experiments are divided into four categories: they are 1. chemical stability test, 2. optimal condition test of stabilization process, 3. bacteriological examination and disinfection tests, and 4. deodorization tests The stabilization process is consisted of the stabilizing reaction process and the drying process. Stabilized wastes is dried by both sun dryer and rotary dryer. It is shown that an additive dosage of about g/kg solid in wastes with a minimum of 5-minutes reaction would be necessary for effective stabilization reaction. The stabilization process is consisted of the stabilizing reaction process and drying process. Stabilized wastes are dried by both sun dryer and rotary dryer. It is shown that an additive dosage of about 300g/kg solid in wastes with a minimum of 5-minutes reaction would be necessary for effective stabilization reaction. In the stabilization reaction process, the pH of wastes is lowered from initial values of 12.3 to 8.6. High pH prevents odor production and kills pathogenic organisms. Organic matter contents in the stabilized wastes are about 50% and the sum of contents of fertilizer elements such as total nitrogen, $P_2O_5$ and $K_2O$ are about 5.3%. The livestock wastes that are stabilized chemically and hygienically can be used as a good soil conditioner and/or organic fertilizer.

• Korean Journal of Organic Agriculture
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• v.20 no.4
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• pp.715-725
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• 2012

This study was performed to make the method of food waste manufacturing for feeding to earthworm and different ratio of earthworm cast was investigated for applying vegetable plants that cultivated in a family or roof garden. We made conventional treatment of gardening soil and prepared soils with earthworm cast (the only fertilizer) at 30, 50, 70 and 100% for planting vegetable plants and then we studied its growth feature. The treatment was repeated three times with 12 weeks for each time. The cultivation of radish and chinese cabbage were managed at the same cultivation level for RDA standard cultivation method, and each sample of soils and plants was analyzed by appropriate analysis method. The growth investigation was performed 12 week after planting, and as for growth characteristics, height, leaf diameter, leaf number, leaf length, fresh weight and dry weight were investigated. The chemical characteristics, soils and plants, were surveyed. As for the growth characteristics investigated, radish and chinese cabbage showed the biggest growth in 70% and 50% treatment with average growth of all characteristics, height, leaf diameter, leaf number, leaf length, fresh weight and dry weight, respectively. Applying these results, a new equation for vermicast recommendation for radish and Chinese cabbage in summer (June-August) was presented. The earthworm cast 50% level with the gardening soil showed the high production in chinese cabbage. In case of radish, earthworm cast 70% with gardening soil level showed great growth, significantly.

• Horticultural Science & Technology
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• v.29 no.1
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• pp.16-22
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• 2011

In developing soil wetting agent using polyoxyethylene nonylphenyl ether (PNE) and polyoxyethylene castor oil (1:1; v/v), the effect of application rates on changes in concentration of PNE, initial wetting of peatmoss + perlite (7:3) medium, and growth of hot pepper (Capsicum annuum L. 'Knockwang') plug seedlings were investigated. The elevation of application rates of wetting agent increased the amount of water retained by the root media. The treatment of 2.5 $mL{\cdot}L^{-1}$ showed similar water retention to + control ($AquaGro^L$ 3.0 $mL{\cdot}L^{-1}$). Most of the liquid wetting agent (LWA) incorporated during the medium formulation leached out in the first and second irrigation, then it decreased gradually until 10 times in irrigation. In investigation of the influence of LWA on position of water infiltrating into root media, the vertical water movements in treatments of 0.5, 1.0, and 1.5 $mL{\cdot}L^{-1}$ were much faster than those in 0.0 $mL{\cdot}L^{-1}$ (-control), but relative speed of water movement decreased by the elevation in application rate of LWA to 2.0 or 2.5 $mL{\cdot}L^{-1}$. The evaporative water loss of root media that to contained various rate of LWA and irrigated to reach container capacity was the fastest in -control among the treatments and it delayed as the application rate of LWA was elevated. The plant height of 22.2 cm in 0.5 $mL{\cdot}L^{-1}$ and stem diameter of 3.26 mm in 1.0 $mL{\cdot}L^{-1}$ were the highest among the treatments tested. The treatment of 1.0 $mL{\cdot}L^{-1}$ also had the heaviest fresh and dry weights such among treatments tested as 3.08 g and 0.861 g per plant, respectively. The elevated application rate over than 1.5 $mL{\cdot}L^{-1}$ resulted in decreased seedling growth. The results mentioned above indicate that optimum application rate of LWA is 1.0 $mL{\cdot}L^{-1}$.