• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.22 no.4
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• pp.63-77
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• 2023

This study applies reinforcement learning to effectively operate expressway hard shoulder running (HSR). An HSR algorithm was developed, and its effectiveness was evaluated using the VISSIM microscopic simulation program. The simulation evaluated two aspects: mobility and safety. The DQN-based HSR algorithm found speed improvement of up to 26 km/h. Compared to the current method, the difference in the number of conflicts was not significant. Considering the results, a DQN-based HSR operation has a clear effect, and it is necessary to consider adjusting the current operational criteria.

• Asia Marketing Journal
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• v.9 no.3
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• pp.233-255
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• 2007

본 사례는 외환위기 및 대우 그룹 해체로 인해 존폐의 위기에 처했던 대우증권이 선도업체 위상을 탈환하기까지의 재건 과정에서 실행했던 마케팅 전략 및 영업활동을 분석하고 있다. 이를 통해 경영위기를 효과적으로 극복하고 새롭게 도약하기 위해 활용 가능한 마케팅 및 영업 전략의 일례를 소개하고자 한다. 끝으로 대우증권의 향후 마케팅 과제와 관련된 토의 주제가 제시된다. 국내 증권업계 선두주자였던 대우증권은 1999년 '대우 사태'로 인해 한때 업계 5위까지 추락하고 1조 2,000억원의 적자를 기록하였으며 신용등급은 투자부적격 단계인 CCC+까지 하락하는 등 위기를 맞이하게 되었다. 대우증권이 회생과 재도약을 위해 채택한 마케팅 전략은 '선택과 집중'이었다. 즉, 최대 수익원이자 경쟁력이 있는 사업 분야인 위탁매매(brokerage)에 역량을 우선 집중하여 안정적으로 수익 기반을 다진 뒤 이를 바탕으로 IB(Investment Bank)와 자산 관리(Wealth Management) 등 여타 분야에서의 역량도 점진적으로 강화하는 전략이다. 전략의 실행 방향은 높은 효율성 확보 및 자원의 확충을 통해 시장 지배력과 수익성을 창출하는 것이었다. 전략적 공감대, 오프라인 영업 강화, 현장 및 고객 중시를 위한 기업 자원의 확충 배치를 바탕으로 영업 프로세스, 영업 인프라, 영업 관리, 고객 서비스, 영업 문화의 혁신을 실행한 결과, 대우증권은 증권명가의 옛 명성과 위치를 성공적으로 탈환하게 되었다. 대우증권은 2004년 위탁매매 영업 부문에서 1위 위상을 되찾은 이래 전 사업 분야에서 성장을 지속하였다. 2006년 증권업종 시가총액 1위를 회복하는 등 각종 경영지표는 큰 폭으로 개선되었고, 신용등급은 AA-로 상향 조정되었다. 나아가 자본시장통합법 시대에 걸맞는 선도 글로벌 투자은행으로서 진화한다는 계획을 추진하고 있다.

• Horticultural Science & Technology
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• v.19 no.4
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• pp.550-554
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• 2001

'Fuyu' persimmon fruits (Diospyros kaki Thunb.) were seal-packaged in $60{\mu}m$ polyethylene (PE) film bags with various $O_2$ and $CO_2$ combinations (0% $O_2$+5% $CO_2$, 2% $O_2$+5% $CO_2$, 2% $O_2$+8% $CO_2$, 5% $O_2$+5% $CO_2$, 5% $O_2$+10% $CO_2$), and in vacuum and air. They were then stored at $-0.5^{\circ}C$ for 95 days. Changes in fruit weight, firmness, soluble solids, Hunter L and a values, $CO_2$ concentrations, and marketability were investigated at 20-day intervals. A combination of 2% $O_2$ and 5% $CO_2$ as well as the vacuum treatment were effective in maintaining firmness, soluble solids, marketability, and Hunter a value of 'Fuyu' fruits. On the other hand, the treatment of 2% $O_2$ combined with 8% $CO_2$ and vacuum treatment were effective in maintaining fresh weight and Hunter L and a values. The highest marketable quality was maintained when the fruits were vacuum-sealed, although fruits softened severely in the area where two fruits contacted with each other.

• Horticultural Science & Technology
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• v.19 no.4
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• pp.505-510
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• 2001

To improve germinability of carrot seeds of 'Inari', 'Mansan', 'Mussang', and 'Hongsim' cultivars, various levels of solid matrix priming (SMP) and the physiological changes of seeds associated with SMP were examined. As the ratio of water in a seed-Micro Cel E-water mix and priming duration increased, seed germinability enhanced. However, there was radicle protrusion during SMP in some cultivars, indicating the existence of cultivar different variations of the optimum conditions. The optimum ratio for a seed-Micro Cel E-water mix was 5 : 3 : 10.5. In this mix, the optimum durations for the treatment were 3 days for 'Mansan' and 5 days for other cultivars. SMP at $20^{\circ}C$ to $25^{\circ}C$ resulted in a higher germination percentage and a shorter $T_{50}$. Seeds absorbed water quickly within an hour and the percentage of moisture was stable at 43 to 49 after 24 hours of the treatment. Conductivity of the mix declined for the first 6 hours to $100{\mu}S{\cdot}cm^{-1}$ with little changes thereafter. On the other hand, the pH of the mixed increased slightly during the early phase, and then returned to the initial level as the treatment proceeded.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.33 no.1
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• pp.71-80
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• 2013

According to design specifications for structural safety, a bridge in initial design step has been modelled to have larger self-weight, external loads and less stiffness than those of real one in service. Thereby measured buffeting responses of existing bridge show different distributions from those of the design model in design step. In order to obtain accurate buffeting responses of the in-site bridge, the analysis model needs to be modified by considering the measured natural frequencies. Until now, a Manual Tuning Method (MTM) has been widely used to obtain the Measurement-based Model(MBM) that has equal natural frequencies to the real bridge. However, since state variables can be selected randomly and its result is not apt to converge exact rapidly, MTM takes a lot of effort and elapsed time. This study presents Buffeting Response Correction Method (BRCM) to obtain more exact buffeting response above MTM. The BRCM is based on the idea the commonly used frequency domain buffeting analysis does not need all structural properties except mode shapes, natural frequencies and damping ratio. BRCM is used to improve each modal buffeting responses of the design model by substituting measured natural frequencies. The measured natural frequencies are determined from acceleration time-history in ordinary vibration of the real bridge. As illustrated examples, simple beam is applied to compare the results of BRCM with those of a assumed MBM by numerical simulation. Buffeting responses of BRCM are shown to be appropriate for those of in-site bridge and the difference is less than 3% between the responses of BRCM and MTM. Therefore, BRCM can calculate easily and conveniently the buffeting responses and improve effectively maintenance and management of in-site bridge than MTM.

• Journal of Korean Society of Environmental Engineers
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• v.39 no.5
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• pp.282-287
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• 2017

The purpose of this study was predicted the effects of mixing and diffusion due to the operation of the apparatus before the development of the mixed diffusion device for the decontamination absorbent to minimize the influence of contaminant inflow due to radiation accident. The tracer used for the flow characteristics was $^{68}Ga$, $^{99m}Tc$, which is a radioactive isotope, and 2 inch NaI radiation detector was used to detect it. The impeller of the decontamination mixed diffusion system applied to this study was made into three types and the mixing diffusion effect was compared. As a result of analyzing the flow characteristics of the radio-isotope with decontamination mixed diffusion device, mixing, diffusion and flow pattern were obtained. The radial mixing type impeller was able to diffuse to the water surface by the upflow flow, and the fin structure was adjusted for finding optimal conditions. The model 3 type consists of a fin guiding part and an auxiliary fin so that the diffusion speed is higher than that of other types of impellers. It also showed a short time to reach complete mixing.

• Korean Journal of Food Science and Technology
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• v.43 no.5
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• pp.558-563
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• 2011

In the course of our investigation for chemical constituents in the ethyl acetate layer of Korean black raspberry wine, five compounds were isolated and purified by silica gel column chromatography and high-performance liquid chromatography. The isolated compounds were identified as ethyl succinate (1), vanillic acid (2), ethyl 3,4-dihydroxybenzoate (3), furan-2-ol (4), and 4-(4-hydroxyphenyl)butan-2(S)-ol (5) based on the spectroscopic data of electrospray ionization tandem mass spectrometry and nuclear magnetic resonance. The presence of 2 in Korean black raspberry has previously reported. However, 1 and 3-5 in Korean black raspberry and its wine were isolated for the first time.

• Journal of the Korean Society for Railway
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• v.16 no.1
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• pp.40-46
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• 2013

Based on Korean railway design standards, the thicknesses of the reinforced roadbeds of conventional and high speed railways are different, and so too, for the size distribution of the ballast particles. Accordingly, considerable cost would be required to increase operating speeds of conventional lines, in particular related to changing from a ballasted track system to a ballastless one. In this study, applicability of a roadbed which supports conventional ballasted track, for use as a ballastless track for a high speed rail line was examined. A reinforced roadbed for a conventional railway is 20cm thick, and the type of material used for a conventional reinforced roadbed is M-40 (crushed gravel for road embankments). A dynamics test was conducted to evaluate the occurrence of the permanent settlement of the track substructure. These results suggest that, without changes to the track substructure, an operational speed of 400km/h is feasible with a ballastless track. This result; however, is from laboratory experiments. Further studies, such as numerical analyses or field validation, are required.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.27 no.5
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• pp.345-352
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• 2014

In this paper, the CAD data for the optimal shape design obtained by isogeometric shape optimization is directly used to fabricate the specimen by using 3D printer for the experimental validation. In a conventional finite element method, the geometric approximation inherent in the mesh leads to the accuracy issue in response analysis and design sensitivity analysis. Furthermore, in the finite element based shape optimization, subsequent communication with CAD description is required in the design optimization process, which results in the loss of optimal design information during the communication. Isogeometric analysis method employs the same NURBS basis functions and control points used in CAD systems, which enables to use exact geometrical properties like normal vector and curvature information in the response analysis and design sensitivity analysis procedure. Also, it vastly simplify the design modification of complex geometries without communicating with the CAD description of geometry during design optimization process. Therefore, the information of optimal design and material volume is exactly reflected to fabricate the specimen for experimental validation. Through the design optimization examples of elasticity problem, it is experimentally shown that the optimal design has higher stiffness than the initial design. Also, the experimental results match very well with the numerical results. Using a non-contact optical 3D deformation measuring system for strain distribution, it is shown that the stress concentration is significantly alleviated in the optimal design compared with the initial design.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.29 no.1C
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• pp.83-91
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• 2004

An epipolar rectification is the process of transforming the epipolar geometry of a pair of images into a canonical form. This is accomplished by applying a homography to each image that maps the epipole to a predetermined point. In this process, rectified images transformed by homographies must be satisfied with the epipolar constraint. These homographies are not unique, however, we find out homographies that are suited to system's purpose by means of an additive constraint. Since the rectified image pair be a stereo image pair, we are able to find the disparity efficiently. Therefore, we are able to estimate the three-dimensional information of objects within an image and apply this information to object segmentation. This paper proposes a rectification method for object segmentation and applies the rectification result to the object segmentation. Using color and relative continuity of disparity for the object segmentation, the drawbacks of previous segmentation method, which are that the object is segmented to several region because of having different color information or another object is merged into one because of having similar color information, are complemented. Experimental result shows that the disparity of result image of proposed rectification method have continuity about unique object. Therefore we have confirmed that our rectification method is suitable to the object segmentation.