• Proceedings of the Korea Information Processing Society Conference
• /
• 2004.05a
• /
• pp.447-450
• /
• 2004

B2C 전자상거래 분야의 대표격인 인터넷쇼핑몰은 유통산업의 구조에 큰 영향을 미침에 따라 쇼핑몰의 성공적 구축 및 운영이 주된 이슈로 떠오르고 있다. 본 연구에서는 최근 웹사이트 평가모델로 주목 받고 있는 3C-D-T 모델을 기반으로 보완하여 국내 인터넷쇼핑몰 웹사이트 평가에 보다 최적화된 평가모형을 제시하였다. 평가모형의 보완은 주로 평가영역 부분에서 이루어졌는데, 인터넷 쇼핑몰 웹사이트에서 비교적 비중이 적은 Community 영역의 평가점수가 전체 웹사이트 평가에 주는 영향을 최소화 시키는 의미가 있었다. 그리하여 3C-D-T 모델의 평가영역의 Commerce 항목과 Community 항목을 통합하여 새로이 Com&Com 항목을 구성했고, 그것으로 보다 최적화 된 인터넷쇼핑몰 웹사이트 평가모형을 구축할 수 있었다. 그리고 이 새로운 평가모델로 국내 메이저 종합쇼핑몰 웹사이트들을 분석, 비교평가 하였다.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.25 no.3A
• /
• pp.352-361
• /
• 2000

The performance of a multi-carrier CDMA system is analyzed considering frequency selective multipath fading and Near/Far effects. The number of multicarrier, multiuser, and arms of RAKE receiver, and the decay ratio of frequency selective multipath fading are used as a parameter for the performance analysis. More over, the distribution and the strength of multiuser interference are also considered. To evaluate the Near/Far effects in a multi-carrier CDMA system, three distribution models are assumed. In the first model, interference to carrier Ratio, I/C, ranges from -4 dB to 4dB, and at each 2 dB interval, 20 % of multiuser is assumed to be uniformly distributed. In the second one, I/C ranges from -2 dB to 2 dB, and 33.3% of multiuser is assumed to be equally dispersed at each 2dB interval. The third model is 0 dB of I/C, that is, with perfect power control, multiuser are assumed to be evenly located. In this paper, multi-carrier CDMA system adoption RAKE receiver is proposed to mitigate the frequency selective multipath fading. From the results, the third model(i.e. perfect power control) shows the best performance, and the narrower range of I/C causes the less effects to the desired signal, which reads to the better performance.

• Journal of the Korea Concrete Institute
• /
• v.19 no.5
• /
• pp.585-593
• /
• 2007

This paper presents a model for durability evaluation of concrete structures exposed to marine environment, considering mainly a build-up of surface chloride $(C_s)$ as well as diffusion coefficient (D) and chloride threshold level $(C_{lim})$. In this study, time dependency of $C_s$ and D were extensively studied for more accurate evaluation of service life of concrete structures. An analytical solution to the Fick's second law was presented for prediction of chloride ingress for time varying $C_s$. For the time varying $C_s$, a refined model using a logarithm function for time dependent $C_s$ was proposed by the regression analysis, and averaging integrated values of the D with time over exposed duration were calculated and then used for prediction of the chloride ingress to consider time dependency of D. Durability design was also carried out for railway concrete structures exposed to marine environment to ensure 100 years of service life by using the proposed models along with the standard specification on durability in Korea. The proposed model was verified by the so-called performance-based durability design, which is widely used in Europe. Results show that the standard specification underestimates durability performances of concrete structures exposed to marine environment, so the cover depth design using current durability evaluation in the standard specifications is very much conservative. Therefore, it is found that utilizing proposed models considering time dependent characteristics of $C_s$ and D can evaluate service lift of concrete structures in marine environment more accurately.

• Proceedings of the Korean Society of Computer Information Conference
• /
• 2020.01a
• /
• pp.7-9
• /
• 2020

기존 CCTV 비디오에서 딥러닝 기반의 이상 탐지 연구는 객체의 행동 값만을 이용하여 이상을 탐지하였기 때문에, 시간 흐름에 따른 정보가 축소되는 문제점이 있었다. 그러나 CCTV 비디오에서의 이상의 원인은 다양한 요소와 시계열 분석에 따른 정보로 이루어져 있어 시간 정보를 유지하면서 다양한 특징 값을 사용한 모델을 설계할 필요가 있다. 따라서 본 논문에서는 C3D에 광학 흐름을 결합한 새로운 앙상블 모델을 제안한다. 실험 결과 본 논문에서 제안하는 모델이 75.83의 AUC를 얻어 기존에 연구되었던 행동 값만을 사용한 모델보다 높은 정확도를 달성하였다. 또한 이상 탐지 모델 설계 시 객체의 행동에 다양한 측면을 고려할 수 있는 여러 특징 값과 시계열 분석에 따른 정보를 사용하는 것이 적절하다는 결론을 도출하였다.

• Applied Chemistry for Engineering
• /
• v.17 no.6
• /
• pp.625-632
• /
• 2006

Dependence of the critical micelle concentration (CMC) on temperature is examined from a statistical-mechanical point of view. A simple and primitive model examined in this article yields ln CMC= A+BT+C/T+D ln T with T being temperature and A, B, C, D being constants depending on the properties of the surfactant molecules which comprise the micelles. The resulting equation combines Muller's and Lim's equations, which have already been proven to fit well measured CMC data with temperature. The statistical-mechanical model on micellization discussed in this article provides a theoretical basis on these equations.

• Asian Journal of Turfgrass Science
• /
• v.9 no.2
• /
• pp.119-129
• /
• 1995

Decomposition rates of glucose, starch, spinach leaves and litters in forests are calculated by equation dC dt=-kC(Co-1nC), dC- dt=$-kC^2$, and Olson's negative exponential decay model.dC dt = - kC =-kC(Co - InC) showed a very close fit to decomposition of the organic matters in cultural media by purified microorganisms and dC dt=$-kC^2$ to decomposition of the litters in forests. Key words: Organic matters, Cultural media, Glucose, Starch, Leaves, Litters.

• Journal of the Korean Society for Aeronautical & Space Sciences
• /
• v.41 no.11
• /
• pp.921-930
• /
• 2013

Satrec Initiative successfully developed and verified a high-resolution electro-optical camera system, EOS-D Ver.1.0. We designed this system to give improved spatial and radiometric resolution compared with EOS-C series systems. The thermal control subsystem (TCS) of the EOS-D Ver.1.0 uses heaters to meet the opto-mechanical requirements during in-orbit operation and uses different thermal coatings and multi-layer insulation (MLI) blankets to minimize the heater power consumption. Also, we designed and verified a refocusing mechanism to compensate the misalignment caused by moisture desorption from the metering structure. We verified the design margin and workmanship by conducting the qualification level thermal vacuum test. We also performed the verification of thermal math model (TMM) by comparing with thermal balance test results. As a result, we concluded that it faithfully represents the thermal characteristics of the EOS-D Ver.1.0.

• Food Science and Preservation
• /
• v.24 no.6
• /
• pp.778-785
• /
• 2017

This study was conducted to develop a predictive model for the growth of Escherichia coli strain RC-4-D isolated from red kohlrabi sprout seeds. We collected E. coli kinetic growth data during red kohlrabi seed sprouting under isothermal conditions (10, 15, 20, 25, and $30^{\circ}C$). Baranyi model was used as a primary order model for growth data. The maximum growth rate (${\mu}max$) and lag-phase duration (LPD) for each temperature (except for $10^{\circ}C$ LPD) were determined. Three kinds of secondary models (suboptimal Ratkowsky square-root, Huang model, and Arrhenius-type model) were compared to elucidate the influence of temperature on E. coli growth rate. The model performance measures for three secondary models showed that the suboptimal Huang square-root model was more suitable in the accuracy (1.223) and the suboptimal Ratkowsky square-root model was less in the bias (0.999), respectively. Among three secondary order model used in this study, the suboptimal Ratkowsky square-root model showed best fit for the secondary model for describing the effect of temperature. This model can be utilized to predict E. coli behavior in red kohlrabi sprout production and to conduct microbial risk assessments.

• Proceedings of the KIEE Conference
• /
• 2008.11a
• /
• pp.53-55
• /
• 2008

본 논문에서는, 기존의 문헌에 사용되어 온 $\Gamma$형을 대체할 수 있는 새로운 T형 장거리 송전선로 모델을 제시한다. 특히, T-모델은 선로 양단의 병렬 어드미턴스와의 중복이 없다. 또한, 기존 문헌에 제시된 hyperbolic solution을 이용한 간단한 장거리 송전선로 A,B,C,D 파라미터 유도방법을 소개한다. hyperbolic solution으로 장거리 송전선로 파라미터를 유도할 경우, exponential solution보다 수식의 양을 줄일 수 있고, 초기값도 간단하게 구할 수 있다.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.21 no.2
• /
• pp.58-65
• /
• 2020

3D Models of offshore plant piping materials designed by 3D CAD systems are provided to the production processes in the form of 2D piping drawings and 2D piping installation drawings. In addition to the standard engineering information, the purchasing, procurement, manufacturing, installation, and inspection of raw materials are managed systematically in an integrated process control system. The existing integrated process management system can help reduce the processing time by managing the flow and progress of resources systematically, but it does not include 3D design model information. Hence, it is difficult to understand complicated pipe structures before installing the pipe. In addition, when design changes or immediate design modifications are required, it is difficult to find related data or exchange information quickly with each other. To solve this problem, an offshore plant-piping process-monitoring system was developed based on a 3D model. The 3D model-based piping monitoring system is based on Visual Studio 2017 C# and UNITY3D so that the piping-process work information can be linked to the 3D CAD model in real time. In addition, the 3D model could check the progress of the pipe installation process, such as block, size, and material, and the progress of functional inspection items, such as cleaning, hydraulic inspection, and pneumatic inspection.