• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.9 no.5
• /
• pp.1154-1163
• /
• 2008

DAS and SCADA system are main systems, which operate and manage the power system by using computer and communication technology. But DAS and SCADA have been operated independently in Korea, so there was some time delay in the fault handling and live-line work. To improve that problems, studies on the interface between DAS and SCADA have been needed. From November 2005 to December 2007, the pilot project has been performed in KEPCO's branch offices, as a result, direct method will be applied widely all over the country until 2010 because the operation information of substation users want can be transmitted fast and it is possible to control 43RC directly although the expense for direct method is about 1.3 times larger than that for web method. To improve problems revealed during the pilot project, substation object to object communication method is proposed and interface database automatic generation and interface system diagnosis and logging functions are developed. Interface data point and communication data type are defined, substation single line diagram automatic generation or manual editing function, SCADA monitoring and controlling function, log data managing function are developed in SCADA HMI program. It is expecting to reduce the average time for each outage about 33% and to improve the reliability, efficiency of operation, execution of DAS from automatic load transfer under a fault, and to contribute to export project.

• Journal of Applied Biological Chemistry
• /
• v.54 no.1
• /
• pp.41-46
• /
• 2011

A galactose-fermenting yeasts, Saccharomyces cerevisiae No. 9, was selected by screening their abilities to produce carbon dioxide gas when grown on galactose. The selected strain, No. 9 and the reference strains NRRL Y-1528 which was exceptionally resistant to high concentration of substrate, were acclimated on sugars such as glucose, mannose, and galactose, and then their ethanol productivities were investigated during fermentation on these three carbon sources. Ethanol productivity of the strain No. 9 reached to the maximum levels after 18 h of fermentation and the ethanol yield was from 36 to 38% when presented as $[EtOH]_{max}/[Sugar]_{ini}(g/g)$, regardless of the conditions of acclimation. From the results obtained by acclimation and fermentation, it was concluded that the ethanol yields from galactose were not affected by the sugars acclimated. Improvements of the strain S. cerevisiae No. 9 were attempted to increase the fermentation efficiency and/or ethanol yields on high concentration of substrate by the conventional mutation methods employing methanesulfonic acid, ethyl ester (EMS). Mutants, Mut-5 (SJ1-40), -17 (LK4-25) and -24 (LK2-48) fermented galactose at the concentration of 20% in the levels of higher 39.9~51.6% than the mother strain, No. 9, however, their ethanol yields never exceeded those of the reference strain.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.18 no.1
• /
• pp.107-114
• /
• 2017

A turbocharger is an engine supercharger that is driven by exhaust gas. It improves the output and fuel efficiency by increasing the charging efficiency of the mixture gas, which is achieved by changing the rotatory power of the turbine connected to the exhaust passage. It is important to control the supercharging for this purpose. A nozzle slide joint is one of the core parts. Austenitic stainless steel is currently used as the material for this part, and its excellent mechanical properties include high heat resistance and corrosion resistance. However, because of its poor machinability, there are many difficulties in producing products with complicated shapes. Machining is used in the production of nozzle slide joints for high dimensional accuracy after metal powder injection molding. As design variables in this study, we investigated the sintering temperature, product stress, deformation rate, radius of curvature of the punch, and angle of the chamfer punch, which are related to the strain and shapes. The goal is to suggest a forming process using Nitronic 60 that does not require machining to manufacture a nozzle slide joint for a turbocharger. Accordingly, we determined the best process environment using finite-element analysis, the signal-noise ratio, and the Taguchi method for experiment design. The relative density and hydrostatic pressure of the final product were in accordance with the results of the finite element analysis. Therefore, we conclude that the Taguchi method can be applied to the design process of metal powder injection molding.

• Journal of Korea Multimedia Society
• /
• v.10 no.11
• /
• pp.1496-1506
• /
• 2007

The environment of web service has changed a great deal due to the progress of internet technology and positive participation of users. The established web service is static and passive, but the recent web service is becoming dynamic and active. Web 2.0 reflects current web service change well. The primary feature of web 2.0 is positive participation of users. Since the size of generated information is becoming larger, it is highly required to share the information fast and correctly. The technology to satisfy this need is web syndication and tagging in web 2.0. The web syndication makes feeds for another site or users to receive the content of web site. In addition, the tagging is the kernel of a information. Many internet users share rapidly the information through tag search. In this paper, we propose the efficient technique to improve the web 2.0 technology such as web syndication and tagging by using the data collection engine. Data collection engine has stored in a database, a user's Web site to use the information. and it has a user's Web site with access to updated data to collect. The experimental results show that our approach can improve the search speed up to 3.14 times better than the existing method and reduce the size of data up to 66% for building associated tags.

• Korean Journal of Construction Engineering and Management
• /
• v.18 no.6
• /
• pp.26-37
• /
• 2017

Preliminary scheduling at the initial stage of planning phase is usually performed with limited information and details. Therefore, the reliability and accuracy of preliminary scheduling is affected by personal experiences and skills of the schedule planners, and it requires enormous managerial effort (or workload). Reusing of historical data of the similar projects is important for efficient preliminary scheduling. However, understanding the structure of historical data and applying them to a new project requires a great deal of experience and knowledge. In this context, this paper propose a framework and methodology for automated preliminary schedule generation based on historical database. The proposed methodology and framework enables to automatically generate CPM schedules for airport projects in the early planning stage in order to enhance the reliability and to reduce the workload by using structured knowledge and experience.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.18 no.3
• /
• pp.249-257
• /
• 2017

Filtering the data for travel time records obtained from DSRC probes is essential for a better estimation of the link travel time. This study addresses the major deficiency in the performance of TRANSGUIDE in removing anomalous data. This algorithm is unable to handle unstable traffic flow conditions for certain time intervals, where fluctuations are observed. In this regard, this study proposes an algorithm that is capable of overcoming the weaknesses of TRANSGUIDE. If TRANSGUIDE fails to validate sufficient number of observations inside one time interval, another process specifies a new validity range based on the median absolute deviation (MAD), a common statistical approach. The proposed algorithm suggests the parameters, ${\alpha}$ and ${\beta}$, to consider the maximum allowed outlier within a one-time interval to respond to certain traffic flow conditions. The parameter estimation relies on historical data because it needs to be updated frequently. To test the proposed algorithm, the DSRC probe travel time data were collected from a multilane highway road section. Calibration of the model was performed by statistical data analysis through using cumulative relative frequency. The qualitative evaluation shows satisfactory performance. The proposed model overcomes the deficiency associated with the rapid change in travel time.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.18 no.5
• /
• pp.400-411
• /
• 2017

This study aimed to maximize the effectiveness of motionbeat rhythm exercise on obese women and its applicability in all fields of sports. In addition, this study aimed to propose a plan to promote continuous exercise for people to incorporate as a means to improve healthy lifestyle. The results showed several effects of EEG on health promoting behaviors. Electroencephalogram (Alpha Power) of the left prefrontal cortex showed to have a significant effect on health promotion activities, with respect to stress management, in the motion beat rhythm exercise group. Considering all research findings, we found that the 8-week motion beat exercise can be used as an appropriate and effective social sport program for overweight women as it brings forth positive changes in the prefrontal cortex that maximizes the pleasantness of and interest in health promotion activities relating to stress management. Moreover, we suggest that it can be a method to create an environment for overweight people to continuously participate in exercises by providing results from fun and relaxingactivities, rather than just creating simple physical effects.

• Resources Recycling
• /
• v.24 no.3
• /
• pp.44-50
• /
• 2015

Recycling technologies would be required in consideration of increasing demand in lithium ion batteries (LIBs). In this study, the leaching behavior of Ni, Co and Mn is investigated with ammoniacal medium for spent cathode active materials, which are separated from a commercial LIB pack in hybrid electric vehicles. The leaching behavior of each metal is analyzed in the presence of reducing agent and pH buffering agent. The existence of reducing agent is necessary to increase the leaching efficiency of Ni and Co. The leaching of Mn is insignificant even with the existence of reducing agent in contrast to Ni and Co. The most conspicuous difference between acid and ammoniacal leaching would be the selective leaching behavior between Ni/Co and Mn. The ammoniacal leaching can reduce the cost of basic reagent that makes the pH of leachate higher for the precipitation of leached metals in the acid leaching.

• KIPS Transactions on Computer and Communication Systems
• /
• v.6 no.9
• /
• pp.397-406
• /
• 2017

In case of using the existing encrypted algorithm for massive data encryption service under the cloud environment, the problem that requires much time in data encryption come to the fore. To make up for this weakness, a partial encryption method is used generally. However, the existing partial encryption method has a disadvantage that the encrypted data can be inferred due to the remaining area that is not encrypted. This study proposes a partial encryption method of increasing the encryption speed and complying with the security standard in order to solve this demerit. The proposed method consists of 3 processes such as header formation, partial encryption and block shuffle. In step 1 Header formation process, header data necessary for the algorithm are generated. In step 2 Partial encryption process, a part of data is encrypted, using LEA (Lightweight Encryption Algorithm), and all data are transformed with XOR of data in the unencrypted part and the block generated in the encryption process. In step 3 Block shuffle process, the blocks are mixed, using the shuffle data stored with the random arrangement form in the header to carry out encryption by transforming the data into an unrecognizable form. As a result of the implementation of the proposed method, applying it to a mobile device, all the encrypted data were transformed into an unrecognizable form, so the data could not be inferred, and the data could not be restored without the encryption key. It was confirmed that the proposed method could make prompt treatment possible in encrypting mass data since the encryption speed is improved by approximately 273% or so compared to LEA which is Lightweight Encryption Algorithm.

• Journal of rehabilitation welfare engineering & assistive technology
• /
• v.5 no.1
• /
• pp.125-132
• /
• 2011

The Comprehensive Assistive Technology services delivery was devised to describe the full social and engineering context of assistive technology devices, systems, applications, and provision. It is based on a detailed decomposition of the four attributes: Person, Context, Activities, and Assistive Technology. The paper commences will a brief discussion of the different representations of the services delivery, including rental of devices, modification of manufacture goods and customized production and the use of engineering to supplement some elements of the description. The main contribution of the paper is the presentation of two case studies of different applications of the assistive technology services. These are the identification of accessibility barriers, the analysis and synthesis of assistive technology systems and the provision of a framework for identitying end-user requirements, providing assistive technology and assessing the associated outcomes. This case study involves the presentation of the concept of a personal assistive technology profile.