• Journal of Korea Society of Industrial Information Systems
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• v.26 no.4
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• pp.19-32
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• 2021

It is well known that any maintenance works for aircrafts must be carried out strictly in accordance with the specified maintenance manuals, especially for military airplanes. According to our previous studies, the largest portion of the maintenance jobs for military aircrafts is found to be related to the assembly/disassembly of various parts, which requires precise understanding of the work procedures as well as correlation between interconnected parts let alone grasping of the exact shapes of parts involved. However, the conventional manuals for aircraft maintenance have failed to provide enough information required for the efficient maintenance except for simple texts and vague pictures, which are far from being sufficient sets of information. On the contrary, unlike incomplete conventional manuals with poor contents, 3D modeling SW could provide us with not only powerful visualization tool even to see through inside any assembly but also freedom to watch parts under test from any angle we want. In addition, the maintenance personnels could learn the precise maintenance procedures through repeatedly watching 3D animated version of the maintenance work as if they were on the field. In this study, we have suggested the efficient procedures to develop 3D manual for aircraft maintenance using 3D modeling SW, Solidworks and implemented a 3D maintenance manual for Integrated Drive Generator(IDG) in Boeing 747. Characteristics of the developed 3D manual has been analyzed in comparison with the conventional ones as well. It is shown that the suggested method could be easily applied to develop a 3D maintenance manual for commercial airplanes since the maintenance works involving assembly/disassembly of major parts are very similar regardless of aircraft types.

• Korean Journal of Organic Agriculture
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• v.7 no.2
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• pp.179-188
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• 1999

The effects of earthworm casts as a plant growth media on the growth of orchardgrass seedlings and the changes of physico-chemical properties in worm casts mixture soils were investigated during the growth period of 1998. Worm casts were mixtured with vermiculite, perlite and peat moss, and mixture ratios of worm casts with commercial recommended soil were 100:0(control), 75:25, 50:50, 25:75, and 0:100, respectively. The results were obtained as follows; 1. Plant length(PL) was increased in higher mixture ratios of worm casts and peat moss than those of other mixture ratios of commercial recommended soils. 2. Number of tillers(NT) were significantly increased in mixture ratios of worm casts and peat moss(50:50) and 100% of vermiculite. 3. Root length(RL) was significantly differences between mixture ratios at the worm casts, and the highest value was obtained at all mixture ratios of worm casts and perlite. 4. Dry weight of leaf(LW) was not significantly differences at mixture ratios of 50:50 in all treatments. Especially, between the mixture ratios of worm casts with peatmoss(25:75) and peat moss(75:25) were not significantly differences in dry weight of leaf(LW). The highest value of dry weight of leaf(LW) was obtained at mixture ratios of peat moss and worm casts. 5. Dry weight of tillers(SW) was not significantly differences at mixture ratios of 50:50 in all treatments, and peat moss(75:25) and vermiculite(75:25), respectively. 6. biological yield(BY) at all treatments were increased by yield components of dry weight of tillers(SW), dry weight of root(RW) and length of root(RL). 7. The biological yield of orchardgrass seedlings was greatly increased with mixture ratios of worm casts and peat moss over the 50%.

• Proceedings of the Korean Information Science Society Conference
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• 2012.06a
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• pp.18-20
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• 2012

클라우드 컴퓨팅의 발전으로 지금까지의 In-House 또는 COTS(Commercial Off The Shelf) 방식으로 구축되는 기존의 정보 시스템 구축 방법에 많은 변화가 일어나고 있다. 클라우드 컴퓨팅은 SaaS(SW as a Service), PaaS(Platform as a Service), IaaS(Infra as a Service)를 쉽게 제공하는 플랫폼으로써 많은 사용자가 동시에 접근하는 정보 시스템에서 고 가용성, 성능 만족을 위한 기본 틀을 제공한다. 본 연구는 최신 클라우드 플랫폼 조사를 통해 위성 영상 통합 시스템에 클라우드 컴퓨팅 기술 적용 가능성을 살펴보고 SaaS 기반 위성 영상 통합 시스템 개념 구조를 제시한다.

• Journal of the Korean Society for Precision Engineering
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• v.23 no.9 s.186
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• pp.149-155
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• 2006

This paper is concerned with the weight reduction of front side member of a vehicle considering the application of high strength steel sheet. The influence of steel sheet grade and thickness on the energy absorption, impact load and deformed shape of front side member is investigated by using reverse engineering and FE-analysis. The reverse engineering is applied to obtain 3D model of front side member from B.I.W for the FE simulation. FE analysis is carried out with commercial crash analysis SW PAM-CRASH. The crashworthiness of front side member is considerably improved with steel sheet strength and thickness increase. From the result of this study the weight reduction in automotive parts for the improvement of the fuel efficiency can be easily achieved with replacing high strength steel without deterioration of crashworthiness.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1994.10a
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• pp.279-287
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• 1994

This paper is prepared as a developmental study of tited axis pistion type hydraulic motor for military applications. The high power precision hydraulic motor requires more advanced techniques to design, analyze, manufacture, test and evaluate. We are trying to build a HW/SW technology base about hydraulic motor by accomplishing this study completsly. We manufactured four perproduction model and performed the test and evaluation with the developmental specifications and test equipments. These results will be used in performance analysis and estimation, and the advanced model development for the military and commercial hydraulic motors.

• The Journal of the Korea institute of electronic communication sciences
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• v.15 no.2
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• pp.219-224
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• 2020

In this paper, we studied the compact MIMO(: Multi-Input Multi-Output) antenna for multi-beam pattern generation and control in narrow space. The characteristics and performance of the basic Dipole SPA and Monopole SPA structures are shown. We implemented a monopole SPA antenna and measured its performance in an 802.11g system. When the average transmission rate was measured using the SPA antenna, the SPA antenna improved the best performance by 8.7 times compared to commercial antenna.

• Journal of Information Technology Services
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• v.9 no.4
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• pp.123-133
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• 2010

There are many occasions on which the critical decisions should be made in software projects. Those decisions are basically related to estimating and predicting project parameters such as costs, efforts, and duration. The project managers are looking for methods to make better decisions. The decisions about project parameters are recommended to be performed based on historical data of Similar projects. The measures of the tasks in past projects may have different shapes of distributions. we need to add those measures to get a predicted project measures. To add measures with different shapes of distribution, we need to use Monte Carlo Simulation. In this paper, we suggest applying Monte Carlo Simulation for supporting decision makings in software project. We implemented best-fit case and scheduling estimations with Cristal Ball, a commercial product of Monte Carlo simulation and showed how the suggested approach supports those critical decision makings.

• Proceeding of EDISON Challenge
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• 2016.03a
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• pp.373-376
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• 2016

Transition metal dichalcogenides (TMDs) such as $MoS_2$ is the thinnest semiconductor, exhibits promising prospects in the applications of optoelectronics, catalysis and hydrogen storage devices. Uniform and high quality $MoS_2$ is highly desirable in large area for its applications on commercial scale and fundamental research. Many experimental techniques i.e CVD have been developed to successfully synthesis $MoS_2$ on large scale, here in this work atomistic detail to understand the growth mechanism is addressed which was greatly overlooked. Here based on first principles calculation we found that polarity of seeding promter (crystal violet considerd in this work) controls the growth mechanism. It is also found that molybdenum destroys the precursor while sulfur adsorption with precursor is favorable.

• Korean Journal of Breeding Science
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• v.42 no.1
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• pp.61-74
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• 2010

Flour characteristics of 26 Korean wheat cultivars (KWC) were evaluated to assess consumer satisfaction with 6 imported wheat and 5 commercial wheat flours. In physical characteristics of flours, Particle size of SW (soft white) was similar to Dahong, Geuru, Milsung, Olgeuru, Seodun, Tapdong, and Uri. DNS (dark northern spring) was similar to Jeokjoong, Joeun, Sukang, and Younbaek. Ash and damaged starch content of KWC was similar to that of imported wheat and commercial flour (Com), but lightness value ($L^*$) were lower than those of Com. Particle size of flour positively correlated with ash, damaged starch, and lightness value ($L^*$) of flour. L ($^*$) value of flour negatively correlated with ash, damaged starch, and particle size of flour. In protein characteristics, Protein content of SW and commercial flour for baking cookie (Com5) was similar to Baekjoong, Jinpoom, Milsung, Olgeuru, Saeol, and Uri. HRW (hard red winter) and commercial flour for baking bread (Com3) was similar to Hanbaek, Joeun, Jopoom, Keumkang, and Sukang. SDS sedimentation volume based on a constant flour weight (SDSS) of KWC was lower than those of DNS and Com3. Mixograph water absorption of KWC similar to imported wheat and Com. Mixing time and maximum dough height (Hm) of KWC were higher than those of imported wheat and Com. Protein content positively correlated with SDS sedimentation volume and water absorption of mixograph. SDS-sedimentation volume positively correlated with water absorption of mixograph, mixing time of mixograph, and height of dough development. In starch characteristics of flour, ASW (Australian standard white) flours showed lower amylose content, higher peak viscosity, breakdown, and setback in pasting properties than other flours. KWV flours showed higher amylose content and lower peak viscosity than those of AH (Australian hard), ASW, commercial flour for making white salted noodles (Com1), commercial flour for making yellow alkaline noodles (Com2), and Com3.

• Journal of Advanced Navigation Technology
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• v.13 no.3
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• pp.319-326
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• 2009

In this paper, the key technologies of Navigation receiver for GNSS sensor station are presented as a development result of a GNSS ground station in ETRI. A wide-band antenna and RF/IF components and SW signal processing unit to cover the GPS and Galileo signals for GNSS receiver are developed and its performance is verified by using GPS live signal and GNSS RF signal simulator from SpirentTM. We also gather GIOVE-A signal by using H/W antenna and RF/IF units in IF-level as sampling frequency and bit number, 112MHz and 8bits, respectively by using the developed wide-band antenna and RF/IF components. Data acquisition is done by using commercial data acquisition device from National Instrument TM. The gathered data is fed into SW receiver to process Galileo E1 to verify Galileo signal processing by Galileo live signal from GIOVE-A.