• 유공압시스템학회:학술대회논문집
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• 2010.06a
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• pp.66-69
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• 2010

A punched pipe in a muffler for an automobile has many important variables, like location of holes in the pipe and length of the pipe related to noise reduction of a diffuser. This pipe is cut depending on length of product and this process, generally workers cut pipes by hands. In this process, there are many errors and it relies on the skill of workers, so it can happen that cycle time for complete product gets long and productivity gets low. Therefore, we need a vision system to distinguish holes in the punched pipe and a transfer system to set the cutting position automatically by moving the pipe depending on forward and backward part of the holes. This paper explains the development of an automatic transfer device which will cause the beating pipe to be cut correctly, exactly the same length as the product.

• Environmental Analysis Health and Toxicology
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• v.8 no.1_2
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• pp.11-17
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• 1993

Radioactive elements Li/sup +/, Rb/sup +/and Cs/sup +/ effect the period shortening in proportion to the higher concentration on the growth of Neurospora crassa. 1 mM LiCl presented the result of the period length 0.52 h shorter than average circadian rhythm 21.66 h. 1 mM RbCl reduced the period length 1.13 h than control period 21.89 h and 1 mM CsCl reduced 2.12 h than control period 21.89 h. In the equal concentration Cs/sup +/ had an extreme effect. Fatal doses of Li/sup +/, Rb/sup +/ and Cs/sup +/ are 20mM, 30mM and 20mM. In the fatal concentration Neurospora didn't develop more after 7 days and the formation of spores were not given in regular order. Circadian length of Neurospora decreased generally at the last cycle of the growth.

• Journal of Energy Engineering
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• v.5 no.2
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• pp.146-152
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• 1996

A small power reactor core of 108 MW$\_$th/ was designed with some design constraints: 2 year refueling cycle length, soluble boron free operation, low power density, and proven fuel assembly design - Uljin 3'||'&'||'4 design specifications. CASMO-3 and KINS-3 was used to evaluate operational capability for power level control via control rods. Cycle length, power peaking factor, M.T.C., and power coefficients were also checked. Designed core loaded with KOFAs satisfied all design goals. We found that much more burnable poisons are to be loaded with axial enrichment zoning. Control rod assemblies should be located at every other assemblies with more than 3 banks. Additional shutdown banks are proposed for the safe plant cooldown, which could be located at core periphery.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.19 no.12
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• pp.1281-1288
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• 2009

Variation of dynamic characteristics of a low pressure turbine blade with crack length is studied in this paper via both experiments and finite element model. Since most of the turbine blades used in domestic power plants are imported from abroad, it is necessary to understand their dynamic behavior in advance. When experimentally obtained natural frequencies and mode shapes are compared with those from FEM results, they are close to each other in their magnitude. Then, it is more feasible to use finite element model for analyzing the dynamic characteristics of a blade under various operation conditions (rotation speed, temperature, etc) as well as with a crack in the blade.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.40 no.11
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• pp.19-28
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• 2003

The limitation on the dynamic range improvement of the complementary correlation optical time domain reflectometer(CCOTDR) is presented. In CCOTDR, the improvement of dynamic range is function of both the averaging number of measurement cycles and the length of codes. The trade off between the averaging number and the code length restricts the improvement of the dynamic range and a very long code is not effective to improve the dynamic range. In this paper, the improvement limitation on dynamic range caused by the trade off between the averaging number and the code length is presented. For derivation of the trade off, the number of one measurement cycles employing a conventional single pulse method and employing a complementary code method are presented and compared. And the effective maximum code length is presented in addition.

• Journal of the Korean Society for Geothermal and Hydrothermal Energy
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• v.12 no.3
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• pp.24-32
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• 2016

Commercial buildings and institutions are generally cooling-dominated and therefore reject more heat to a borehole ground heat exchanger (BHE) than they extract over the annual cycle. Shallow ponds can provide a cost-effective means to balance the thermal loads to the ground and to reduce the length of BHE. This paper presents the analysis results of the impact of design parameters on the length of SWHE pipe and its application effect on geothermal heat pump (GHP) system using BHE. In order to analysis, we applied ${\varepsilon}-NTU$ method on designing the length of SWHE pipe. Analysis results show that the required pipe length of SWHE was decreased with the increase of approach temperature difference and with the decrease of pipe wall thickness. In addition, when the SWHE was applied to the GHP system, the temperature of BHE was more stable than that of standalone BHE system.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.18 no.2
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• pp.77-92
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• 2019

TPCLT is a advanced signal system that serves twice left turn phases during the same cycle. TPCLT can be a useful where the left turn traffic volume is high and the length of the left turn lane is short. This study examined the effectiveness of TPCLT in reducing delay for a signalized three-Leg intersection and proposed the application of TPCLT signal system. 108 scenarios with different traffic volumes were created. This study analyzed the control delay of the three-Leg intersection in case TPCLT is operated and non-TPCLT is operated. As a result of analysis, it was shown that TPCLT was effective in most of the scenarios. When traffic volume ratio of the left turn is 30~40%, TPCLT was more effective at reducing the control delay. The study result shows significant delay reduction for the left turning traffic and it is approximately 50 seconds. The opposing movement's average control delay increased 2 seconds. The effect of TPCLT on the length of left turn lane was analyzed. As a result, it is found that TPCLT is effective when the length of left turn lane is 30%~60% compared to that of conventional three leg intersection operations.

• Journal of Korean Tunnelling and Underground Space Association
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• v.8 no.3
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• pp.219-225
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• 2006

Although the round length for tunnel excavation has a major technical and economical impact in conventional tunnelling, there is no coherent procedure available for its determination. In this study, the influence of round length on the behaviour modes of weak rock tunnel was investigated by numerical analyses. Quantitative estimation of the behaviour modes of the face and the unsupported span was established by use of the safety factor for the face stability and the conditional chart. In addition, the optimum round length in the tunnel design stage was investigated based on the detail construction information such as cycle time and material costs. Although this proposed method has some restrictions, it is expected to provide useful information for the optimization of the tunnel excavation, especially in design stage.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.22 no.9
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• pp.1307-1316
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• 1998

Engine turbulences obtained by LDV measurement near the compression TDC was analyzed by the classic turbulence theory. Turbulences were quantified by a cycle resolved analysis and processed to reveal integral time scale and length scale. Three different definitions were applied to obtain the turbulence time scales and then compared each others. The classic turbulence theory with the several assumptions for engine application proven to be very efficient for understanding engine turbulence in this study. It was found that the integral length scale is strongly affected and increased by tumble flow.

• Journal of Aquaculture
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• v.17 no.1
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• pp.30-38
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• 2004

To estimate the spawning period the annual change of gonadosomatic index (GSI) were examined from January 2000 to December 2001. Fecundity, spawning frequency and egg diameter were measured by ocular observation. Germ cell differentiation during gametogenesis, the reproductive cycle and the first sexual maturity of greenling Hexagrammos otakii were observed under light microscopy from January to December, 2000. GSI began to increase in August and reached the maximum in November when ovary was getting mature. The reproductive cycle of H. otakii can be divided into five successive stages in females: early growing stage (July), late growing stage (July to August), mature stage (September to October), ripe and spent stage (September to December), and recovery and resting stage (December to June). Males showed four successive stages : growing (June to August), mature (August to October), ripe and spent (September to December), and recovery and resting stage (December to May). According to the frequency distributions of egg diameter in spawning season, H. otakii could be one of polycyclic species spawning 2 times or more during one spawning season. Number of total eggs and mature eggs in the absolute fecundity were related to the standard length and body weight, respectively. Number of total eggs and mature eggs in relative fecundity were also proportional to the standard length, but rather these numbers decreased with body weight. Percentages of first sexual maturity of females and males in greenling were over 50% from 19.1 to 21.1cm in length, and 100% for fish over 25.1cm in length. Therefore, both sexes are ready to reproduce after one year old.