• Journal of the Korean Society of Propulsion Engineers
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• v.15 no.6
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• pp.56-62
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• 2011

An experimental study on design of a catalytic ignitor was performed to use an ignition source for a small bi-propellant liquid rocket engine which use hydrogen peroxide and kerosene as propellants. In the catalytic ignitor, hot gas of hydrogen peroxide which was decomposed by a catalyst induced autoignition of kerosene. Mass flow rate and O/F ratio for the ignitor were calculated by CEA code. A combustion chamber which had a quartz window and thermocouples was manufactured to determine whether the ignition is successful. Ignition performance was investigated according to exit area of fixed rings and mixture ratio. Results showed that reliable ignition performance was achieved at non-choking exit area of fixed ring and O/F ratio of 6~8.

• Journal of the Korean Society of Propulsion Engineers
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• v.14 no.5
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• pp.57-64
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• 2010

A performance test of inter propellant seal for a 75 ton class turbopump is conducted using water to evaluate leakage and endurance performance. Each part of fuel pump side and oxidizer pump side for a prototype inter propellant seal has been tested for verifying endurance performance during total accumulated test time 2,100 sec in water. The fuel pump side part with one-stage seal of carbon floating ring shows average leakage rate 13.7 gram/sec under average seal differential pressure 9.4 bar. On the other hand, the oxidizer pump side part with two-stage seal assembly of carbon floating rings shows average leakage rate 7.3 gram/sec under average seal differential pressure 9.5 bar. After the endurance performance test, the inter propellant seal shows good physical condition. A leakage performance test of the inter propellant seal for cryogenic environment will be performed using LN2 in the near future.

• The Research Journal of the Costume Culture
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• v.23 no.6
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• pp.1097-1115
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• 2015

ICT in the IOT era is the core basis of modern society. This study investigated and analyzed the recent commercialization trends of smart fashion products internationally and domestically, to utilize them as the basis of data for developing user-friendly smart fashion products that can meet the needs of consumers. Keyword research using the most representative search engines, Google and Naver was conducted for searching for various wearable items commercialized actively since 2010. The final 78 products were classified by the physical area, and the key features and benefits were analyzed. Smart fashion products were classified as four physical types for the head and face, torso, arms and hands, and ankles and feet. Smart fashion products for each body part were developed in various ways, such as hats, glasses, lenses, virtual screens, earphones, headsets, clothing, watches, wrist bands, gloves, rings, wallets, bags, anklets, shoes, socks, and insoles. The main features were music playback, bluetooth, a camera based on NFC, virtual effects, health and safety protection through measuring heartbeat and momentum, and social network sharing of all kinds of information, based on inter-working with a smartphone. These functions represent the physical, social, and emotional interactions among users and their surroundings, as well as the users, themselves. The research results are expected to be used in future studies on planning user-friendly and marketable products through in-depth analysis of the design characteristics of smart fashion products as well as consumer responses.

• Journal of the Korean Chemical Society
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• v.16 no.5
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• pp.271-283
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• 1972

The rate Constants and energies of activation for the Combustion reaction of Korean anthracites have obtained by DTA method using the following rate equation derived by authors. $K=\frac{C_3{\cdot}W_0}{{\Delta}H{\cdot}{\Delta}C{\cdot}M{\cdot}S_A}(\frac{dy}{dt}+A(y-y_3))$ The anthracites of various ranks were treated at the different temperatures in the furnace. The probable combustion reaction mechanisms have discussed with the results obtained by the X-ray diffraction method, IR spectroscophic analysis, and gas chromatography. By the intensity of d(002) Values, it was confirmed that a parts of the amorphous carbon was converted to graphite form by heat treatment. The appreciable amounts of CO gas were expelled in the combustion process and it appeared that a little amount of the gas came from the catalytic decomposition of anthracites, The functional groups such as -OH, -SH, -NH, $-CH_2-CH_3,$ -CO, -COC-. and polycondensed aromatic rings in anthracites have observed by IR spectrophotometric analysis.

• Journal of the Korean Chemical Society
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• v.7 no.4
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• pp.230-237
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• 1963

The synthesis of 2-methyl-5,5'-gem-disubstituted-$\Delta^2$-thiazolines has been undertaken by two methods. The first involves the preparation of gem-disubstituted N-or S-acetylamino mercaptan intermediates by ring opening of the corresponding thiiranes with ammonia. The second consists of the ring opening of gem-disubstituted ethylene imines using thiolacetic acid. The thiirane rings have never been opened under conditions as vigorous as that of using sodium amide in liquid ammonia. This is probably due to retardation by the gem-disubstituents. In contrast to this, the corresponding ethylene imine ring opens easily, in spite of the same stereochemical situation. The stabilization of gem-disubstituted cyclic compounds has been discussed from a stereochemical point of view. It has been concluded from the results of this work that the compression effect of gem-disubstitution is not due to bond angle deformation, which was observed by Thorpe and Ingold, but mostly to an electronic bond interaction of the gem-disubstituents and to the hetero atom(s), if any.

• Korean Journal of Ichthyology
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• v.29 no.1
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• pp.69-74
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• 2017

Age and growth of Brown croaker Miichthys miiuy were estimated using right sagittal otoliths of 327 fish specimens from August 2015 to July 2016 in Korea. Annual rings in otoliths were formed from March to June once a year. The oldest specimens were 11 yr in female and 9 yr in male. Brown croaker began spawning in September and showed a peak in October. Total length and body weight relationships showed no significant difference between females and males (P>0.05), and can be expressed as $BW=1.15{\times}10^{-5}{\times}TL^{2928}$ ($R^2=0.98$). Estimated von Bertalanffy growth curve was $L_t=182.4(1-e^{-0.067(t+1.754)})$ ($R^2=0.96$).

• Journal of Digital Convergence
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• v.13 no.4
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• pp.377-385
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• 2015

The purpose of the study was to perform trend analysis of the exercise content i.e. element difficulty distribution scores, element group distribution scores obtained by the athletes during 2014 Korea Cup International Gymnastic finals. The conclusion drawn from the analysis are as follows: Firstly in terms of tournament technical difficulty value, Korean athletes showed characteristics of reliance on swing element rather than strength hold element which could actually secure higher difficulty scores. Secondly, skill acquisition of higher difficulty value is demanded by taking advantage of familiar characteristics from the swing element i.e. Jonasson and Roll bwd. Slowly with str. arms and body to swallow (2s.). Thirdly, development of sensory training and strengthening exercise program are essential to enhance strength hold technique.

• Proceedings of the KOR-BRONCHOESO Conference
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• 1982.05a
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• pp.12-12
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• 1982

We have recently experienced a case of decannulation difficulty resulted from head and thoracic injury. The patient was 21-year-old male who undergone craniectomy and tracheotomy at other hospital about 7 months ago prior to admission On admission, there was swelling in glottic and subglottic region in indirect laryngoscopy and bronchoscopy with fixation of vocal cords in paramedian position. We tried to reestablish an adequate air way with bougination using Jackson esophageal bougie but there was no effect with it. So we performed vertical incision through cricoid cartilage and tracheal rings and insertion of Teflon tube in stenotic lesion for 9 months and removed it. At present time, the patient has been satisfactory corking training course.

• The Plant Pathology Journal
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• v.23 no.3
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• pp.215-218
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• 2007

The occurrence and relative incidence of viruses including Cucumber mosaic virus (CMV), Zucchini yellow mosaic virus (ZYMV), Papaya rings pot virus (PRSV), and Watermelon mosaic virus (WMV), Cucumber green mottle mosaic virus (CGMMV), Kyuri green mottle mosaic virus (KGMMV), and Melon necrotic spot virus (MNSV) were surveyed from main melon (Cucumis melo L.) production areas in Jeonnam province during 2000-2002. Virus disease incidences of melon cultivating fields were 0% and 11% in spring and fall 2000; 40%, 2.1%, and 8.8% in spring, summer, and fall 2001; and 6.3 % in spring 2002 in main cultivated areas in Jeonnam province, respectively. Field disease incidences of melon virus infections were 0% and 18.8% in spring and fall 2000; 50%, 38.5%, and 82.6% in spring, summer, and fall 2001; and 47.4% in spring 2002, respectively. Total of 101 melon samples showing typical disease symptoms were collected from 2000 to 2002 and tested for virus infection by RT-PCR. Potyvirus-specific DNA fragments for WMV, ZYMV, and PRSV were amplified from 46, 5, and 4 samples, respectively. MNSV specific DNA fragment was amplified from 18 samples. CMV-specific DNA fragment was detected from only 3 samples.

• Journal of the Korean Society for Nondestructive Testing
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• v.28 no.1
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• pp.1-8
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• 2008

The object of this study is to develop the examination technique for measuring the O-ring deformation behavior under the pressure and the squeezed condition simultaneously. The O-ring deformation measuring device in which two grooves were dug to insert the two O-rings was manufactured to be not deformed under the high pressure and the 1 mm and 0.1 mm gap were designed to measure the extrusion lengths under the internal pressure. The beam hardening correction, the histogram analysis and the dead zone correction were executed to exactly measure the shape of O-ring deformation and the lengths of the O-ring deformation were measured by the LSF and the ERF. The computed tomography applied the pressure of 0, 1.378, 4.902, 9.804, 15.692 MPa at 22.3% squeezed condition and the expanded diameter, contact length and extrusion depth were measured in each pressure. The shape of O-ring deformation was evaluated by the FEM to verify the results of measuring by the computed tomography and the area of O-ring was mutually compared to the area measured by the computed tomography.