• Tribology and Lubricants
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• 제21권1호
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• pp.39-45
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• 2005

Investigation of the mass effect on the journal traces in the clearance of engine bearing has been performed for better design of mass distribution of crank system components such as crank pin, piston, con-rod, balance weight, crank throw weight, etc. as well as for better oil reaction behaviors to the applied forces from the cylinder pressures on the bearing. In this preliminary study, crank pin traces in the engine bearing clearance are computed by varying the equivalent magnitude of crank pin mass that includes the masses of crank pin, piston, con-rod. etc.. while most previous studies regarding journal traces in the bearing clearance neglect the inertia effects of crank pin mass. Although the inertia effect of pill mass is negligibly small compared to viscous force by ${\pi}bearing$ theory, it is found that it gives a great amount of influences on the journal traces in full bearing computation $(2\pi\;bearing\;theory)$ under the dynamic loading conditions.

• Journal of Plant Biology
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• 제8권4호
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• pp.1-6
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• 1965

Cytological observations were carried out to investigate the frequencies and geographical distribution of accessory chromosomes in rye in Korea. (1) All the 41 strains of rye investigated were found to have accessory chromosomes and the frequencies of accessories are ranged from 2 to 73.3%. (2) The frequency ranging from 30 to 40% was predominant and it included 13 different strains. (3) The edaphic factor seemed to play more marked role than the climatic factor in determining geographical distribution of accessories in rye in Korea. (4) Breakages of A-chromosomes into two fragments were observed in 11 plants. This phenomenon may throw some light on possible orgin of accessory chromosomes in rye.

• ETRI Journal
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• 제31권3호
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• pp.342-344
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• 2009

From a hydrodynamic device simulation for the pseudomorphic high electron mobility transistors (pHEMTs), we observe an increase of maximum extrinsic transconductance and a decrease of source-drain capacitances. This gives rise to an enhancement of the switching speed and isolation characteristics as the upper-to-lower planar-doping ratios (UTLPDR) increase. On the basis of simulation results, we fabricate single-pole-double-throw transmitter/receiver monolithic microwave integrated circuit (MMIC) switches with the pHEMTs of two different UTLPDRs (4:1 and 1:2). The MMIC switch with a 4:1 UTLPDR shows about 2.9 dB higher isolation and approximately 2.5 times faster switching speed than those with a 1:2 UTLPDR.

• 대한치과의사협회지
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• 제19권2호통권141호
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• pp.181-185
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• 1981

In this study an attempt has been made to throw some light on the problem of the mandibular third molar on measurement made from 302 orthopantomograms of patients at the age of 8 to 20 years. The following conclusions were drawn on the basis of the present study. 1. The amount of growth from the lower first molar to the anterior border of the ramus from 8 years to 14 years was 7.9mm in the male and 7.5mm in the female. The growth from 15years 20 years was 4.5mm in the male and 2.6mm in the female. 2. The growth from the lower first molar to the posterior border of the ramus from 8 years to 14 years was 10mm in the male and 9.8mm in the female. The growth occurred after that was 5.8mm in the male and 2.0mm in the female. 3. The difference between A and C measurements for the various age groups remained fairly constant in the male and female.

• 한국군사과학기술학회지
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• 제11권5호
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• pp.34-41
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• 2008

This paper describes the design of SP3T PIN diode switch which has a 500W high power handling capability in $20{\sim}400MHz$ frequency range. Design factors were investigated and it was confirmed by simulation that the characteristics of insertion loss, VSWR, and isolation met design goal. Also, the capability to handle 500W high power with very fast switching speed of less than $26{\mu}s$ was confirmed and insertion loss of less than 1dB, VSWR of less than 1.4:1, and isolation of higher than 60dB were obtained by experiments.

• ETRI Journal
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• 제28권1호
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• pp.84-86
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• 2006

This letter presents a small-sized, high-power single-pole double-throw (SPDT) switch with defected ground structure (DGS) for wireless broadband Internet application. To reduce the circuit size by using a slow-wave characteristic, the DGS is used for the quarter-wave (${\lambda}$/4) transmission line of the switch. To secure a high degree of isolation, the switch with DGS is composed of shunt-connected PIN diodes. It shows an insertion loss of 0.8 dB, an isolation of 50 dB or more, and power capability of at least 50 W at 2.3 GHz. The switch shows very similar performance to the conventional shunt-type switch, but the circuit size is reduced by about 50% simply with the use of DGS patterns.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2001년도 춘계학술대회논문집
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• pp.178-183
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• 2001

A multi-stage reciprocating air compressor has many pistons and conneting rods to one crank throw, while a general engine has one connecting rod. Those make its design hard to apply balance weight design method generally using in an engine design, This study introduces a modified balance weight design method in order to calculate the unbalanced inertia properly. Vibration tests on V/W type air compressor have been conducted to prove the usefulness of design program. It is confirmed that the proposed program is applicable to design of balance weight.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2003년도 하계종합학술대회 논문집 I
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• pp.557-560
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• 2003

The increase of vehicles stagnations leads to the increasing attention to the way customers pay and a large number of projects on electronic cash system. Tranport system is comprised of a number of advanced technologies, including information processing, communications, control, and electronics. Recently many research on a system which provides contact in order to protect driver's vehicle passage have been carried out. And some potential problems from that system are being reviewed by electronic cash system. In this papers, we suggest RF protocol developing technology using the concept of electronic cash. ATM electronic cash developing is consist of component of pre-developed coin throw, integration of component using its, and production of more requirement-satisfactory ITS solution. Result increase 15~40% pre-type vehicles stagnations. Especially, we expect this proposed concept would be well adapted to our national environments.

• 통합자연과학논문집
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• 제11권2호
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• pp.101-106
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• 2018

Corticotropin - releasing hormone receptor 1 (CRHR1) forms an integral part of the pathophysiology of disorders like post-traumatic stress disorder, stress, anxiety, addiction, and depression. Hence it is essential to look for new, potent and structure-specific inhibitors of CRHR1. We have analysed the protein-protein interaction complexes of the CRHR1 receptor with its native ligand CRF and full agonist Sauvagine. The structure of Sauvagine was predicted using homology modelling. We have identified that the residues TYR253, ASP254, GLU256, GLY265, ARG1014 and LY1060 are important in the formation of protein-protein complex formation. Future studies on these residues could throw light on the crucial structural features required for the formation of CRHR1-inhibitor complex and in studies that try to solve the structural complexities of CRHR1.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2000년도 춘계학술대회논문집
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• pp.1040-1045
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• 2000

This paper presents results of coupled axial and torsional vibration analysis of shafting system in large diesel engines and generators for stationary power plants. Axial vibration of the shafting system takes place due to mainly torsional deformation or vibration and breathing effect of crank throws, caused by cylinder gas forces and reciprocating inertia of the engine. Cross-coupled stiffness matrix of the crank throws is calculated employing a finite element model of the crank throw and a static condensation method. Forced response analysis of the shafting system is performed using the calculated stiffness matrix and derived governing equations.