• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.25 no.8A
• /
• pp.1169-1176
• /
• 2000

In this paper, label assignment schemes considering the IP flow model for the efficient MPLS traffic engineering are proposed and evaluated. Based on the IP flow model, the IP flows are classified into transient flows and base flows. Base flows, which last for a long time, transmit data in high bit rate, and be composed of many packets, have good implications for the MPLS traffic engineering, because they usually cause network congestion. To make use of base flows for the MPLS traffic engineering, we propose two base flow classifiers and label assignment schemes where transient flows are allocated to the default LSPs and base flows to explicit LSPs. Proposed schemes are based on the traffic-driven label triggering method combined with a routing tabel. The first base flow classifier uses both flow size in packet counts and routing entries, and the other one, extending the dynamic X/Y flow classifier, is based on a cut-through ratio. Proposed schemes are shown to minimize the number of labels, not degrading the total cut-through ratio.

• Horticultural Science & Technology
• /
• v.17 no.3
• /
• pp.361-364
• /
• 1999

This study was conducted to examine the effects of pulsing treatment and to develop techniques treated right after harvest by grower for extending vase life and improving flower quality in cut freesia. Thirty minutes dipping treatment of STS 2 mM followed by 20 hr pulsing in sucrose 10% + BA 10 ppm + 8-HQS 300 ppm solution showed the best results in vase life and flower quality of cut freesia when kept in vase water. This pretreatment extended vase life by 24.7% than control, and improved quality of cut freesia significantly in flower diameter, percent flowering (35.4%), fresh weight, water uptake, and carotenoid content, and depressed ethylene production and respiration rate.

• Journal of Korean Ophthalmic Optics Society
• /
• v.8 no.2
• /
• pp.25-29
• /
• 2003

Nickel-ferrite $Ni_xFe_{3-x}O_4$ thin films with several composition for Ni on glass substrate was prepared by ferrite plating method in order to make sunglass which cut off ultraviolet and shield electromagnetic field. It has single phase of polycrystalline spinel structure and has gloss as mirror and has high hardness which is no scratch while scraping by using nail. The transmittance of nickel-ferrite thin film is lowered to zero below 400 nm manifestly. And it shows that the nickel-ferrite thin film in nickel composition rate x = 0.09 was most cut oil ultraviolet when compared with goods of other company in the cut off effect of ultraviolet. Therefore, sunglasses coated with $Ni_xFe_{3-x}O_4$ thin film can be used in removing ultraviolet and electromagnetic field.

• Journal of The Korean Society of Grassland and Forage Science
• /
• v.4 no.2
• /
• pp.152-157
• /
• 1983

This study was carried out to investigate changes in the quality and botanical composition of native pasture during the grazing period. The results obtained were as follows: 1. On all the farms, the total dry matter yield of native pasture was much higher in the October-cut than in the July-cut. 2. The crude protein content was higher in the July-cut than in the Oct.-cut, while the crude fiber content gave opposite results. There was the same tendency on all the farms. 3. When the six farms were compared, the highest crude protein content was found at Hawon and Haian farm, and cows on these farms showed the highest daily weight gain. Ohra farm had the lowest crude protein and the cows on this farm the lowest daily weight gain. 4. The botanical composition of the main species distributed was 58.1% Zoysia japonica, 16.4 Pteridum aquilinum, and 3.8% Miscanthus sinensis. In the case of family, 72.1% were Gramineae, 1.8% Leguminosae, and 16.4% Pteridacea. 5. According to botanical composition of a family, Hawon farm had the highest daily weight gain and the highest rate of Gramineae and Leguminosae. Ohra and Youngkang farms had the lowest weight gains, but the native grassland on these farms contained a high proportion of Pteridum which is toxic to cattle.

• Journal of the Korean Geotechnical Society
• /
• v.24 no.8
• /
• pp.81-88
• /
• 2008

In this study, to determine the priority of the effect factors and the preferences of commonly used reinforcing methods for the cut-slope, the reasonable analysis using AHP technique was performed. Analytic Hierarchy Process (AHP) technique is the most widely used method out of all existing decision making methods. On choosing the methods, the most important factor is analyzed to be the stability and durability. Stability, durability and environmental compatibility took up over 50% of the total contributing factors. Cut-slope reinforced method preference with increasing stability method confirmed that concrete retaining wall, reinforced-soil wall and cutting method showed the highest preference rate. Also, in practical field conditions, the cutting method out of four methods was chosen to be the most effective method. This reflected that the methods that are equally superior in all aspects of evaluation factors are more important than the methods with superiority in highly prioritized evaluation factors.

• Korean Journal of Agricultural Science
• /
• v.30 no.1
• /
• pp.89-101
• /
• 2003

For the pre-feasibility study and project evaluation, the discount rate or cutoff rate should be given by the government authority. To get the Benefit/Cost Ratio, NPV(Net Present Value) and IRR(Internal Rate of Return) of the public investment projects, the pertinent and realistic discount rate should be determined to be suitable to the present time period. The cut-off rates in Korea were equivalent to 15% in 1970's, 10% in 1980's and 8% in 1990's. The prevailing rate of discount as 8% is considered not to be suitable for the 2000's public project appraisal considering the present interest rates on deposit and national bonds. To determine the socio-economic feasibility of the public projects, the IRR should be bigger than the present cutoff rate. When we still use the high old rate of discount, the analytical results of project appraisal will show always economically unfeasible. Therefore the new rate of discount suitable for present time should be determined by the government. The public projects to be implemented in 2000 year onward are recommended to be adapted 5% of cutoff rate for the project appraisal and evaluation according to the results of reviewing the tendency of discount rates and market rates of interest in Korea.

• Journal of the Korean Society of Manufacturing Technology Engineers
• /
• v.6 no.1
• /
• pp.69-76
• /
• 1997

This paper deals with the machinability based on turning and drilling tests. The main conclusions obtained were as follows. (1) Turning : The roughness of Machined surface decreases with the increase of the rake angle of tools, and the tool wear becomes smaller with the decrease of the rake angle. When the feed rate becomes larger, the fracture of work material in the vicinity of the cutting edge occurs on a larger scale, eventually decreasing tool wear. (2) Drilling : Considering both tool life and productivity, it is reasonable to cut with the high cutting speed and feed rate. The tool wear increases with the increase of feed rate, and the tendency of feed rate on tool wear becomes stronger at the cutting speed $\geq$30m/min.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
• /
• 2000.06a
• /
• pp.402-406
• /
• 2000

In the Over-The-Range, the outlet size is limited by the industrial standards. Therefor to enlarge the volume of cavity, the installation height of ventilation fan is become small, the system resistance is higher than before. For that reason, the important design variables such as the diameter of a fan, the scroll expansion angle, etc. which play the significant role on flow rate and noise, are confined. In this study, we made an experiment of the diameter of fans relation to scroll expansion angle and investigated flow rate of the length of fans in enlarged cavity volume of OTR, and then we designed the new scroll to improve the flow rate and noise level. As a result, flow rate increased to 110% compared to current scroll and the blade passing frequency of a fan is disappeared by inclined cut-off shapes.

• IE interfaces
• /
• v.9 no.1
• /
• pp.1-10
• /
• 1996

In this study, expert system for the selection of the optimal cutting speed and feed rate was developed using NEXPERT system shell. The NC system has been usually used inefficiently because the input command, which contains cutting speed, feed-rate and the depth of cut, is fixed value which depends on principally operator's experience and machining handbooks providing a guideline for applicable ranges. On the other hand, the optimal cutting conditions vary with time, and depend on tool and machine characteristics, work materials, and cost factor and so on. In this study, if cutting factors, such as, cutting method, material type, cutting depth, and tool nose radius are specified, our expert system gets the information about the standard cutting speed form the cutting speed database, and provides optimum feed rate for these cutting conditions. This cutting speed database can be updated by inputting valid cutting speed which is obtained form the practices.

• Journal of the Korean Society of Manufacturing Technology Engineers
• /
• v.21 no.1
• /
• pp.144-149
• /
• 2012

The cutting characteristics of hardened aluminum alloy A17075-T6 were investigated during turning processing. Under variation conditions of cutting speed, depth of cut, and feed rate, the characteristics of cutting force, surface roughness, and machined texture were investigated. Surface roughness became worse in proportion to the increase of the feed rate. The thickness of material alteration layer which is derived from the effect of cutting force was the biggest when feed rate 0.148mm/rev. This research confirmed that the deformed layer is dominantly dependent on the variation of feed rate.