• Korean Journal of Fisheries and Aquatic Sciences
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• v.18 no.1
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• pp.8-14
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• 1985

A circulation water channel with observational section of $4m{\times}2.4m{\times}1m(length{\times}breadth{\times}depth)$ and the maximum channel flow speed of 2 m/sec was designed for model tests of fishing gears. It consists of 6 sections evenly divided for easy connection. Two observational acryl windows of $1.2m{\times}1.5m$ and 2cm thick are provided. Steel deflection plates, equally spaced in 20-40cm, are fixed at corners of the channel to reduce the loss of water pressure head through the channel. The flow in the channel is controlled by D.C. motor control system with 50 H.P. driving propeller system. A series of model testing capabilities for fishing gear have been examined and the results are as follows. 1) The speed of water flow was in the range from zero to 2.3 m/sec. 2) The difference between the velocity of channel flow along the center line and that along both sides in the channel was less than 0.2 m/sec.

• Journal of the Korean Chemical Society
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• v.13 no.3
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• pp.221-228
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• 1969

The nucleophilic addition rate constants of n-amyl-, n-hexyl-, n-octyl-and n-decyl mercaptide ion to 3,4-methylenedioxy-${\beta}$-nitrostyrene were determined and found to be 2.82 ${\times}10^8$ $M^{-2} .sec^{-1}$, 1.00 ${\times}10^8$ $M^{-2}.sec^{-1}$, 2.23 ${\times}10^8$ $M^{-2} .sec^{-1}$ and 1.77 ${\times}10^8$ $M^{-2}.sec^{-1}$ respectively. At low pH, for n-amyl-, n-hexyl-, n-octyl-and n-decyl mercaptan the values determined are 2.82 ${\times}10^{-2}$ $M^{-1} . sec^{-1}$, 1.95 ${\times}10^{-2}$ $M^{-1} . sec^{-1}$, 7.08 ${\times}10^{-2}$ $M^{-1} . sec^{-1}$ and 5.63 ${\times}10^{-2}$ $M^{-1} . sec^{-1}$ respectively. The rate equations which can fully explain the addition mechanism over wide pH range were also be obtained.

• The Journal of the Korea institute of electronic communication sciences
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• v.13 no.4
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• pp.721-728
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• 2018

This paper introduces various linear block error correction code and compares performances of the correction circuits. As the risk of errors due to power noise has increased, ECC(: Error Correction Code) has been introduced to prevent the bit error. There are two representatives of ECC structures which are SEC-DED(: Single Error Correction Double Error Detection) and SEC-DED-DAEC(: Double Adjacent Error Correction). According to simulation results, the SEC-DED circuit has advantages of small area and short delay time compared to SEC-DED-DAEC circuits. In case of SED-DED-DAEC, there is no big difference between Dutta's and Pedro's from performance point of view. Therefore, Pedro's code is more efficient than Dutta' code since the correction rate of Pedro's code is higher than that of Dutta's code.

• Journal of Korean Society of Transportation
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• v.8 no.2
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• pp.43-54
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• 1990

Six Levels of Service are defined for each type of facility for which analysis procedures as available. They are given letter designations, from A to F with Level of Service A representing the best operating conditions and Level of Service F the worst. Yet the appropriate criteria by vehicle delay model in our situations are not formed. Therefore, The objective of this study is to form the criterion of by average approach delay based on the criterion of V/C ratio. Level-of-Service criterion of this study by TRANSYT-7F Delay Model is as follows. A:${\leq}35.5$ sec, B:${\leq}41$ sec, C:${\leq}48$ sec, D:${\leq}56.5$ sec, E:${\leq}66.5$ sec, F:>66.5 sec.

• 한국해양학회지
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• v.1 no.1_2
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• pp.7-13
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• 1966

한국해협(韓國海峽)을 통과(通過)하는 해수용적수송량(海水容積輸送量)의 계절(季節) 및 영년변화(永年變化)에 대(對)하여 기존자료(旣存資料)를 써서 지형유리론(地衡流理論)에 입각(立脚)하여 계산(計算) 음미(吟味)하였다. 한국해협(韓國海峽)을 통과(通過)하는 “쯔시마” 난류(暖流)의 북방수송량(北方輸送量)은 약 $2{\times}10^6m^3$/sec의 우세(優勢)한 년변화량(年變化量)을 갖고 동춘절(東春節)의 $0.33{\times}10^6m^3$/sec 로부터 하추절(夏秋節)의 $2.21{\times}10^6m^3$/sec 사이에서 변화(變化)한다. 그리고 정미(正味)의 수송량(輸送量)의 년평균치(年平均値)는 1935년(年)의 $1.3{\times}10^6m^3$/sec 로부터 1939년(年)의 $0.8{\times}10^6m^3$/sec사이로 변화(變化)하며 영년변화량(永年變化量)은 약 $0.5{\times}10^6m^3$/sec로서 년변화량(年變化量)의 약 1/4밖에 안된다. 북방수송량(北方輸送量)의 영년변화(永年變化)는 약(約) 4년주기(年週期)를 갖는 것 같이 보인다.

• The Journal of Korean Physical Therapy
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• v.12 no.3
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• pp.349-359
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• 2000

The aim of study was to evaluated the possible role of cranial artery velocity in headache pathogenesis. The present study was studied of five headache(F=5. Mean $age=29.80\pm6.76yrs$) were compared to 4 controls(F=4, Mean $age=29.00\pm5.48yrs$). Transcranial doppler ultrasonography(TCD) is a new non-invasive and easily applicable method to evaluate flow velocities of the intracranial and extracranial cerebral arteries. TCD was performed with standard method to measure the mean Flow Velocity(MFV) of the middle and posterior cerebral arteries, the internal carotid artery, the vertebral and the basilar artery. We reviewed the whole TCD results performed at Taejon Veterans Hospital from October. 11. 2000 to November. 10. 2000. Mean flow velocities in headaches and controls at their 6 decades are $28.00\pm3.61cm/sec$ and $41.25pm1.71cm/sec$ in lent PCA (P<0.01), $50,000\pm23.07cm/sec$ and $82.75\pm15.59cm/sec$ in right MCA(P<0.05), $26.20\pm4.82cm/sec$ and $45.50\pm4.51cm/sec$ in fight PCA(P<0.01). $26.60\pm4.56cm/sec$ and $38.25\pm4.92cm/sec$ in right VAC(P<0.01). After treatment for 2 weeks, mean of velocity on pre treatment and post treatment and post treatment are $28.00\pm3.61cm/sec$ and $38.20\pm5.81cm/sec$ in left PCA (P<0.05), $26.20\pm4.827cm/sec$ and $39.20\pm5.54cm/sec$ in right PCA(P<0.05), $40.60\pm9.18cm/sec$ in right VA(P<0.01). It is concluded that Electrical Therapy for two weeks was effected to promote Mean Flow of Velocity in cranial artery. Mean of velocity in cranial artery with headaches observed in this study was lower than controls, but MFV was promote after treatment for 2 weeks.

• Korean Journal of Microbiology
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• v.44 no.4
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• pp.271-276
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• 2008

Ribosome stalling by nascent sticky peptide has been reported in several organisms across the kingdom. To test whether small subunit (SSU) rRNA is involved in this phenomenon, we developed a genetic system that utilized the specialized ribosome system to isolate SSU rRNA mutants that enable ribosomes to bypass the SecM-derived sticky peptide in protein synthesis. In this system, CAT-SecM mRNA, which encodes CAT protein containing the sticky peptide derived from SecM, is only translated by specialized ribosomes. These ribosomes were shown to transiently stall on CAT-SecM mRNA followed by the synthesis of the sticky peptide. Expression of specialized ribosomes resulted in the decreased steady-state level of CAT-SecM mRNA, which is consistent with a notion that ribosome stalling induces mRNA degradation. Isolation and characterization of SSU rRNA mutations using this genetic system that are sufficient to circumvent ribosome stalling induced by the SecM-derived sticky peptide will provide evidence of SSU rRNA function in mRNA cleavage.

• Journal of Korean Society of Transportation
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• v.9 no.2
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• pp.101-120
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• 1991

The Subject of this research work is to study the driver's vision and eye-movement ch-aracteristics under the diffrent condiction of road traffic and driving. The analysis of this investigation was conducted spatially or temporaly into three parts'eye-mark distribution, viewing-time percentage and fixation duration. This dissertation focuses on analysis of dr-iver's visual characteristics to improve road circumstamces. In this study driver's ch-aracteristics are measured with eye-mark recorder and analyzed statistically The main features of this study are : 1st Duration distribution of fixation point is significant in 87% at 5% of the significant level in Gamma Distribution. The average of fixation duration by road are 0.33sec on streets 0.45sec on Roads and 0.86sec on highways. The average of fixation duration by visual objects are 0.4sec on road surface 0.26sec on road shoulder 0.49sec on traffic sign 0.37sec on warning sign and 0.67sex on gwide sign. 2st Moving anglrs of a fixation point are fit in the Exponential Distribution. The average moving angle is appeared to be 3.85。 on streets 2.81。 on roads 2.73。 on highway and 5 。 on intersecyion. 3st As a result of examining alignment of guide and warning sign in traffic signs cxisting foundation methods are less affected by lane than by apeed of a vehicle.

• Proceedings of the KIEE Conference
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• 1998.07e
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• pp.1632-1634
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• 1998

In this paper, the study of influence of DC voltage and AC voltage on residual voltage of XLPE Cable was presented. In the former case, when the DC voltage of -10.0[kV] was applied to XLPE Cable for 0, 600, 1200, 1800[sec], time constants were 2139, 1416, 939, 488[sec] and resistivities were 930, 615.65, 408.26, 212.17[${\Omega}{\cdot}m$] respectively. In the latter case, when the AC voltage of 4 and 6[kV] was applied to the same Cable for 600[sec] after applying DC voltage of -5.0[kV] for 600[sec], time constants were 215, 275[sec] and resistivities were 93.48, 119.57[${\Omega}{\cdot}m$] respectively. In this experiments, measurement voltage, charging time and measurement time were -8.0[kV], 30[sec], 600[sec] respectively.

• 한국태양에너지학회:학술대회논문집
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• 2011.04a
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• pp.111-115
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• 2011

Surface Texturing is an essential process for high efficiency in multi-crystalline silicon solar cell. In order to reduce the reflectivity, there are two major methods; proper surface texturing and anti-reflection coating. For texturization, wet chemical etching is a typical method for multi-crystalline silicon. The chemical solution for wet etching consists of HF, $NHO_3$, DI and $CH_3COOH$. We carried out texturization by the change of etching time like 15sec, 30sec, 45sec, 60sec and measured the reflectivity of textured wafers. As making the silicon solar cells, we obtained the conversion efficiency and relationship between texturing condition and solar cell characteristics. The reflectivity from 300nm to 1200nm was the lowest with 15 sec texturing time and 60 sec texturing time showed almost same reflectivity as bare one. The 45 sec texturing time showed the highest conversion efficiency.