• 대한전기학회:학술대회논문집
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• 대한전기학회 2009년도 제40회 하계학술대회
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• pp.1349_1350
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• 2009

Thin films of pp(ST-Co-VA) were fabricated by plasma deposition polymerization (PVDPM) technique. Properties of the plasma polymerized pp(ST-Co-VA) thin films were investigated for application to semiconductor device as insulator. Thickness, dielectric property, composition of the pp(ST-Co-VA) thin films were investigated considering the relationship with preparation condition such as gas pressure and deposition time. In order to verify the possibility of application to organic thin film transistor, a pentacene thin film was deposited on the pp(ST-Co-VA) insulator by vacuum thermal evaporation technique. Crystalline property of the pentacene thin film was investigated by XRD and SEM, FT-IR. Surface properties at the pp(ST-Co-VA)/pentacene interface was investigated by contact angle measurement. The pp(ST-Co-VA) thin film showed a high-k (k=4.6) and good interface characteristic with pentacene semiconducting layer, which indicates that it would be a promising material for organic thin film transistor (OTFT) application.

• 한국표면공학회:학술대회논문집
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• 한국표면공학회 2001년도 춘계학술발표회 초록집
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• pp.73-73
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• 2001

Boron-containing materials have several excellent properties, such as superlnardness, insulation and non-Rinear optical property. Recently, oxynitride compounds, such as Si(ON), Ti(ON), became the promising materials applied in diffusion barrier layer and solar cell. With the expectation of obtaining the hybrid property, we have firstly grown the BON thin film by radio frequency (R.F.) plasma enhanced metalorganic chemical vapm deposition (PEMOCVD) with 100 kHz frequency and trimethyl borate precursor. The plasma source gases used in this study were Ar and $H_2$, and two kinds of nhmgen source gases, $N_2$ and <$NH_3$, were also employed. The as-grown films were characterized by XPS, IR, SEM and Knoop microlhardness tester. The relationship between the films hardness and the growth rate indicated that the hardness of the film was dependent on several factors such as nitrogen source gas, substrate temperature and film thickness due to the variation of the composition and the structure of the film. Both nitrogen and carbon content could raise the film hardness, on which nitrogen content did stronger effect than carbon. The smooth morphology and continuous structure was benefit of obtaining high hardness. The maximum hardness of BON film was about 10 GPa.

• Korean Chemical Engineering Research
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• 제58권2호
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• pp.230-234
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• 2020

딥러닝 기법을 활용하여 분자 구조로부터 물성을 예측하는 시스템은 화학, 생물학, 재료 연구에 적용하기 위해 개발되었다. 분자 구조와 물성 정보가 축적된 데이터베이스를 기반으로, 구조와 물성간의 관계식을 찾는 딥러닝 모형을 구축한 후 최종적으로는 새로운 분자 구조에 대한 물성 예측값을 제공할 수 있다. 또한 선정된 분자 구조의 실제 물성값에 대한 실험을 병행하여 지속적인 검증 및 모형 업데이트를 수행하게 된다. 이를 통해 다량의 분자구조로부터 물성이 우수한 분자 구조를 빠른 시간 안에 스크리닝할 수 있으며, 연구의 효율성 및 성공률을 높일 수 있다. 본 논문에서는 딥러닝을 활용한 물성 예측 시스템의 전반적인 구성과 LG화학에서 실제 신규 구조 발굴에 적용된 사례를 중심으로 소개하고자 한다.

• 한국분말재료학회지
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• 제30권3호
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• pp.223-232
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• 2023

Metal additive manufacturing (AM) has transformed conventional manufacturing processes by offering unprecedented opportunities for design innovation, reduced lead times, and cost-effective production. Aluminum alloy, a material used in metal 3D printing, is a representative lightweight structural material known for its high specific strength and corrosion resistance. Consequently, there is an increasing demand for 3D printed aluminum alloy components across industries, including aerospace, transportation, and consumer goods. To meet this demand, research on alloys and process conditions that satisfy the specific requirement of each industry is necessary. However, 3D printing processes exhibit different behaviors of alloy elements owing to rapid thermal dynamics, making it challenging to predict the microstructure and properties. In this study, we gathered published data on the relationship between alloy composition, processing conditions, and properties. Furthermore, we conducted a sensitivity analysis on the effects of the process variables on the density and hardness of aluminum alloys used in additive manufacturing.

• 한국해양공학회:학술대회논문집
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• 한국해양공학회 2001년도 춘계학술대회 논문집
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• pp.43-48
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• 2001

Price of Used Vessel is Key-point of Ship trading but it is very troublesome part. Because it is different from the Seller and the Buyer's caculated price, It is appropriated by The Sellers and The Buyers' mutual agreement. In case of the Buyers. it is difficult in calculating price of used ship without entrusting the ship broker, beca- use evaluation method of secondhanded vessel has not formulated and the ship broker has experientially computed Remain Value of used vessel. For this work, structure of ship trading market, trading flow, the factor of price composition and Affecting factor of price is reviewed, and it examined relationship with price. On these base, a computer software integrated database system and object-oriented technique is developed. The developed system is expected helpful to evaluation of remain value of the used vessel.

• 한국표면공학회지
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• 제22권3호
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• pp.135-144
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• 1989

Aluminium Oxide was deposited with a C.V.D.-technique on various substrates. The effects of various treating condition such as temperature, time, heat resistance and composition of substrates were investigated in order to understand the relationship of structure, property and process. Grain size depends upon the activity of adsorption siite and coarsened with increasing temperature and time. Deposition rate decreases in order of electrolytic iron, carbon steel STS430 and STS304, since the active site for adsorption of reactant was more decreased for Cr and Ni than Fe. Oxidation resistance of alumina coated specimens improved markedely and that of stainless steel was prominent.

• 한국물환경학회지
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• 제40권2호
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• pp.79-88
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• 2024

This study employed field measurements and biogeochemical analysis to examine the effects of seasonal conditions (e.g., temperature and precipitation) and human intervention (e.g., dam or weir construction) on the chemical composition of dissolved organic matter, flocculation kinetics of suspended particulate matter, and formation of the fluid mud layer on riverbeds. The results indicated that a water environment with a substantial amount of biopolymers offered favorable conditions for flocculation kinetics during an algal bloom period in summer; a thick fluid mud layer was found to be predominated with cohesive materials during this period. However, after high rainfall, a substantial influx of terrigenous humic substances led to enhanced stabilization of the particulate matter, thereby decreasing flocculation and deposition, and the reduced biopolymer composition served to weaken the erosion resistance of the fluid mud on the riverbed. Moreover, a high-turbulence condition disaggregated the flocs and the fluid mud layer and resuspended the suspended particulate matter in the water column. This study demonstrates the mutual relationship that exists between biogeochemistry, flocculation kinetics, and the formation of the fluid mud layer on the riverine area during different seasons and under varying hydrological conditions. These findings are expected to eventually help inform the more optimal management of water resources, which is an urgent task in the face of anthropogenic stressors and climate change.

• 비파괴검사학회지
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• 제20권3호
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• pp.231-237
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• 2000

공업용 서멧 절삭공구는 다성분계 탄화물과 강자성체(ferromagnetic material)인 철족의 Co, Ni 결합상 금속으로 구성 되어 있다. 본 연구에서는 새로운 시도로서 금속 결합상 량과 소결조건에 따른 TiCN계 서멧의 자기적 특성의 측정에 의한 기계적 성질의 평가방법을 연구하였다. 실험에서는 결합상이 다른 상용 서멧조성의 합금을 분말 야금법에 의해 제조하였다. 소결된 서멧의 자기적 특성은 합금의 조직과 탄소량에 따라 크게 변화하였다. 포화자화(magnetic saturation, $4{\pi}\;{\sigma}$)와 항자력(coercive force, Hc)은 비례하였으며, 고탄소 소결합금에 있어서는 Co-Ni 결합상에서의 W, Mo, Ti등의 용매원자의 농도가 낮아짐에 따라 포화자화는 증가하였다 항자력이 높을수록 경도는 증가하였고, 서멧의 강도 및 인성은 포화자화가 증가할수록 우수하였다. 서멧공구에서 자기적 특성을 측정하여 기계적 성질을 비파괴적으로 평가할 수 있었다.

• 대한가정학회지
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• 제44권10호
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• pp.57-66
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• 2006

The purpose of this study was to evaluate the relationship between the tactile sensation and mechanical properties of towel. Six kinds of towels with different surface structure and fiber composition were used for this study. To evaluate the tactility of towel, 36 adjectives were collected and then 11 adjectives were selected. The subjective evaluation was examined by one to one comparative method and by blind test for estimating the only the sense of touch of the towels. Kawabata's Evaluation system for fabrics was used to measure the mechanical properties which are tensile, bending, shear, compression, surface, weight, and thickness of six towels. The results are as follows; First, surface structure of the towels had an effect on estimation the sense of touch. Pile surface was evaluated thicker, compacter, more cushiony, and more elastic. Waffle surface was evaluated knottier and rougher, and microfiber suede surface was evaluated softer and denser. Second, the highest value of the mechanical properties measured were G, 2HG, B, and SMD of 100% cotton 100% pile, WC, T, and W of elban loop pile, WT, 2HB, and LC of 100% cotton cut pile, RT and MIU of microfiber suede, and RC of microfiber waffle. Third, the 11 adjectives were correlated with more than one mechanical property. 'Knotty' and 'rough' were correlated with MMD and SMD, 'soft' were correlated with B, 2HB, MMD, and SMD. 'Thick', 'heavy', 'compact', and 'elastic' were correlated with WC, T, and W, 'cushiony' was correlated with WC. 'Stiff' was correlated with B and 2HB, 'dry out' was correlated with RT, WC, MIU, and T. 'Dense' was correlated with RT and SMD.

• Journal of Welding and Joining
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• 제31권6호
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• pp.84-89
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• 2013

The demand of LNG tank and the constituting material, i.e., the Al5083 thick plate, increased due to the rapid growth LNG market. To weld the Al5083 thick plate, the gas metal arc welding (GMAW) of high current is necessary to increase manufacturing productivity incurred by the multi pass welding. However, the arc welding vaporizes the volatile element such as magnesium (Mg). This phenomenon changes the Mg composition of the weld metal and the mechanical properties. The study investigated the weldability of Al5083 alloys after conducting high current GMAW. The Al5083 alloy was welded by using different size of welding wires and high current (800-950A). As the arc current increased from 800A to 950A, the mechanical strength decreased and the secondary dendrite arm spacing (SDAS) increased. Even though the arc current increased SDAS, the mechanical strength decreased due to the Mg loss in the weldment. The large diameter of welding wire decreased the dilution of the weld, therefore increasing the Mg content and the strength of the weld. For the reason, the content of Mg in welds was a major parameter to determine the mechanical property for the high current GMAW. For the arc current between 800A and 950A, the yield strength of the weldments showed a relationship with the weight percent of Mg content ($X_{Mg}$): Y.S = 27.9($X_{Mg}$)-11.