• Transactions of the Korean Society of Automotive Engineers
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• v.12 no.4
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• pp.12-23
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• 2004

The effects of improved rice bran oil on the characteristics of exhaust emissions have been experimentally examined by a single cylinder, four cycle, direct injection, water-cooled agricul-tural diesel engine operating at several loads and speeds. The experiments are conducted with light oil, rice bran oil, and improved rice bran oil as a fuel. The fuel injection timing is fixed to 22$^{\circ}$ BTDC regardless of fuel types, engine loads and speeds. To reduce the viscosity of rice bran oil, it is used with the methods of heating, methyl ester and ultrasonic system in a highly viscous rice bran oil. In this study, it is found that the brake specific fuel consumption rate of light oil is the lowest and that of improved rice bran oils is lower than that of pure rice bran oil, and NO$_{x}$ emissions of light oil are the lowest and those of pure rice bran oil are the high- est, while soot emissions of light oil are the highest and those of pure and improved rice bran oils are lower than that of light oil. However these results are not amply satisfied with the emissions regulation limit using the pure and improved rice bran oil as fuels in diesel engines.s.

• Journal of Korean Society of Water and Wastewater
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• v.23 no.4
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• pp.417-430
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• 2009

A BNR comprehensive performance evaluation (BNR CPE) system was established employing system-oriented evaluation methodology for biological nutrient removal (BNR) processes based on the CPE techniques developed by U.S. EPA for evaluation of conventional biological processes. The BNR CPE system applied to five domestic BNR plants adopting $A^2/O$ process confirmed that all target plants except the smallest one had not any serious defective performance and process stability was enhanced with increasing plant size. The system also clearly verified relatively poor performances in anoxic reactors without exception mainly due to influent carbon limit rather than functional defect. Consistent good performances were confirmed even during both winter season and wet weather generally known to be difficult to achieve satisfactory removals. Presentation of evaluation results by modified radar chart system simplified and clarified the evaluation and analysis procedures. The BNR CPE system could not only discover readily the causes of present and prospective poor performances but also facilitate the suggestion of their optimization options. Mutual effect and cause-and-effect among operation parameters and unit processes were also found easily using the evaluation system. The system justified that the adverse effect of defective operating parameters could be compensated by other favorable parameters, especially in anaerobic and anoxic reactors as well as during the winter season.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.14 no.8
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• pp.741-748
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• 2004

The vibration and buckling characteristics of the capsule for fuel irradiation test are studied. The natural frequencies of the capsule in air and under water are obtained by modal testing and finite element (FE) analysis using ANSYS program, and accelerations with flow are measured to estimate the compatibility with the operation requirement of the HANARO reactor. The experimental fundamental frequencies of the capsule in the x and z direction are 8.5 Hz and 8.75 Hz in air, and 7.5 Hz and 7.75 Hz under water, respectively. The maximum amplitude of accelerations under the normal operating condition is measured as 11.0 m/s$^2$ that is within the allowable vibrational limit(18.99 m/s$^2$) of the reactor structure. Also, the maximum displacement at 100％ flow is calculated as 0.13 mm which is not interference with other nearby structures. FE analysis results show that the natural frequencies are found to be similar to those of the modal testing when three supporting parts are considered as simply supported conditions. From the buckling analysis, when the loading tool is applied, the critical buckling load of the capsule is 233 N.

• The Bulletin of The Korean Astronomical Society
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• v.36 no.2
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• pp.92.1-92.1
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• 2011

NASA launched Solar Dynamics Observatory (SDO) on February 2011 in order to understand the cause of solar activities and their influences on the Earth and the near-Earth space. KASI is constructing Korean Data Center for SDO based on the letter of agreement between KASI and NASA for space weather research. SDO produces about 1.5 TB a day and its raw data amounts to about 550 TB in a year. Stanford University has been already operating the data center for scientific raw data, but there is a limit to use its data for space weather research and space weather service in real time because of network environment. Korean Data Center for SDO will provide scientific data not only to Korean institutes but also to international space weather societies. KASI has designed the data transfer system by using GLORIAD in order to get higher performance and stability. After the first construction of data transfer system and storage system in this year, we will increase the storage capacity of the data center in phases considering new developments in a storage technology and drop of their prices.

• Proceedings of the Safety Management and Science Conference
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• 2001.11a
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• pp.65-71
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• 2001

With ever-change and increasingly competitive business environments, firms strive to employ a variety of marketing strategies and execution in order to survive in the market. Such effects would be paid off in the right way only when management of the firms perform marketing activities focusing on long term effectiveness, which would drive company profits up and keep them for long. Demands of customers are being changed and varied. And in this circumstance, it become a main issue of management that the company should produce and sell products according to the customer demands. With these trends, each company has been concentrating effects on generalization of product development technique and distinction of service lot customer In this result with the advantage of mass marketing and database marketing have been drawing attentions from company. Also the internet connected around the world completely diminished the limit of time and distance and company have enveloped keen competition out of each nation and continent in the world market. To fulfill these demands of customer, they need a concept of eCRM(Web based Customer Relationship Management), and go from selling products and services, or gathering customer requests, up to the phase of solving customer's problem by real time or Previous action. With the help of Internet, the frequency and speed of the problem solving has improved greatly.

• Proceedings of the KSR Conference
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• 2009.05a
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• pp.848-854
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• 2009

Of the rapid development of modem civilization development is one of the IT industry. The Network is the root of the discrete industry. Most of the Protocol is used by LAN and the TCP / IP. Slowly in the railway operation of this Network is being applied. It also used to train and they are operated. The concept of the road, the Network TCP / IP using a non-Star structure of the Main Unit and the Bus Network is designed to structure consists of the Network. This structure is a simplified DATA. Data of complex operations is easy to feel the speed limit is. In addition, all devices must be independent to the operating system with the ability to manage the operation and stability in terms of exactly how the transmission of Data is gonna work pass. And transmission occurs in the middle of the Noise and the device is available to manage the power. Noise in the power of the railway to ensure the efficient transfer of Data is by blocking. Also, by presenting the entire system's operational safety should be guaranteed the safety of the railway.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2003.05a
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• pp.1157-1164
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• 2003

Dynamic Load/unload (L/UL) mechanism is an alternative to the contact start stop (CSS) technology which eliminates stiction and wear failure modes associated with CSS. Other benefits of L/UL include increased areal density due to smooth disk surfaces, thinner overcoats, and lower head flying height Improved shock resistance due to elimination of head slap, and reduced power consumption. Inertia latch mechanism becomes important for mobile disk drives because of non operating shock performance. Various types of latch designs have been introduced in hard disk drives to limit a rotary actuator from sudden uncontrolled motion. In this paper, a single spring inertia latch is introduced for a small form optical disk drive, which uses a rotary actuator for moving an optical pick-up. A new small inertia latch with single spring is designed to ensure both feasible and small size. The shock performance of the new inertia latch is experimentally verified.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2013.10a
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• pp.123-126
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• 2013

Access control system, when operating the infrastructure manager and the permissions for the user to clearly define the terminology that is. Various IT incidents still happening frequently occur, and these incidents in order to prevent the situation of access control is needed. In this study, the Copy command by hackers hacking incidents, such as walking dangerous limits for instructions attacks in advance, and also the internal administrator accident accidental limit command to walk off the risk in advance and even if the incident occurred access to the command history log and post it as evidence through the analysis techniques that can be utilized are described.

• The Transactions of the Korean Institute of Electrical Engineers A
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• v.55 no.1
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• pp.45-51
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• 2006

This paper proposes a method to evaluate the Total Transfer Capability (TTC) by considering uncertainty of weather conditions. TTC is limited not only by the violation of system thermal and voltage limits, but also restricted by transient stability limit. Impact of the contingency on the power system performance could not be addressed in a deterministic way because of the random nature of the system equipment outage and the increase of outage probability according to the weather conditions. For these reasons, probabilistic approach is necessary to realize evaluation of the TTC. This method uses a sequential Monte Carlo simulation (MCS). In sequential simulation, the chronological behavior of the system is simulated by sampling sequence of the system operating states based on the probability distribution of the component state duration. Therefore, MCS is used to accomplish the probabilistic calculation of the TTC with consideration of the weather conditions.

• Journal of the Korean Institute of Telematics and Electronics
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• v.26 no.3
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• pp.14-21
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• 1989

In the digital transmission equipment, the input jitter tolerance is a function of input timing recovery circuit characteristics. Especially, in the asynchronous multiplexers, it is also a function of the frame format, the buffer sizes in the synchronizer and desynchronizer, the PLL transfer function, and operating range of VCO in PLL In this paper, a new algorithm for calculating the jitter tolerance of the saynchronous digital transmission equipment is presented. With the new algorithm, we analyzed how the above factors limit the jitter tolerance in the equipment. We also measured the input jitter tolerance for a 45M-140M multiplexing equipment, whose results show the same trend with calculated tolerance.