• Textile Coloration and Finishing
• /
• v.32 no.2
• /
• pp.111-120
• /
• 2020

In this study, lignin/chlorinated poly(vinyl chloride)(CPVC) blended fibers have been produced for the development of low-cost carbon fiber. Carbon fiber manufacturing was accomplished through stabilization and carbonization process. The lignin/CPVC blended fibers were prepared by wet spinning method. Dimethylacetamid e(DMAc) and cychlohexanone in a ratio of 5:1(wt%) was employed as co-solvent. The ratio of lignin/CPVC was prepared at 0/10, 1/9, 2/8, 3/7, 4/6, and 5/5(wt%). The spinning solution was extruded at a rate of 0.1 to 0.4ml/min according to the blending ratio. The speed of the rollers was the same for all ratios(draw ratio=1). Analysis of fiber cross-section by scanning eletron microscopy(SEM) showed that as the lignin ratio increased in the same coagulation bath and distilled water, the pore size of the spinning fiber decreased. Therefore, the highest tensile strength of the blending fibers was 6.3±1.2MPa at the 5/5 ratio. The carbon fiber also showed the best tensile strength of 120.78±2.43MPa at 5/5 ratio.

• Journal of the Korean Society of Fisheries and Ocean Technology
• /
• v.37 no.1
• /
• pp.1-8
• /
• 2001

This study deals with the experimental and numerical investigations to design the high performance otter board. Experiment was carried out to determine the most effective slot size of single-slot cambered otter board in the circulation water channel of BAEK KYUNG IND. Co. LTD. Numerical analysis was done by the commercial CFD code, FLUENT, to provide some valuable physical interpretations and finally to design the otter board section by numerical method. The major results are as follows ; 1. In experiment, the maximum lift and drag coefficients of simple cambered type otterboard were 1.41, 0.55, respectively, at the angle of attack $28^\circ$, while those of slot one with slot size 0.02C (C denotes the chord length) were 1.72, 0.42 at the angle of attack $24^\circ$. 2. The hydrodynamic characteristics depending upon slot size shows the greatest at 0.02C of the slot size. 3. Numerical results well visualized the streamlines, pressure fields, and speed vectors of a simple cambered and slot cambered otter board with slot size 0.02C. The slot cambered one with slot size 0.02C was shown that pressure field was distributed moderately on front and back side of otter board. And, the delay and decrease of separation were favorably achieved by flow through slot. 4. Computed result on the pattern of hydrodynamic field and the values of $C_L$ and $C_D$ by the commercial CFD code, FLUENT, show almost the same as those of the experimental result.

• Journal of the Korean Society for Precision Engineering
• /
• v.29 no.1
• /
• pp.87-95
• /
• 2012

In recent years, laser-arc hybrid welding has begun to be adopted for assembly welding of automotive bodies and parts, because the hybrid welding process can weld lapped steel sheets having a larger gap than is possible with laser welding. In this paper, to predict the twist deformation by the hybrid welding when brackets are welded in B pillar of a passenger car, the residual stress using CAE is analyzed and the deformation result of CAE is compared with the measured deformation. First of all, after modeling heat source as intended to be expressed with laser-arc hybrid welding method, heat source fitting is done with welding conditions and a section of welding part obtained through specimen test. In case of heat source functions, laser used conical source and arc used double ellipsoid source. Through the local model analysis, elements which are located in the center of the model are selected. The elements are called WME(Welding Macro Element). This WME is extruded in the welding lines and welding phenomenon of complex parts is accomplished. The deformation amount after hybrid welding is got through a simulation, the validity of simulation is verified by measuring the panel and comparing with the simulation result.

• Journal of the Korean earth science society
• /
• v.31 no.5
• /
• pp.475-487
• /
• 2010

Sea surface wind field was retrieved from high-resolution SIR-C SAR data by using CMOD algorithms off the east coast of Korea. In order to extract wind direction information from SAR data, a two-dimensional spectral analysis method was applied to the normalized radar cross section of the image. An $180^{\circ}$-ambiguity problem in the determination of wind direction was solved by selecting a direction nearest to the wind vector of the ECMWF reanalysis data. Comparison of the wind retrieval patterns with the ECMWF and NCEP/NCAR dataset showed RMS errors in the range of 1.30 to $1.72\;ms^{-1}$. In contrast, comparison of wind directions revealed large errors of greater than $60^{\circ}$, which is enormously higher than the permitted limit of about $20^{\circ}$ for satellite scatterometer winds. Compared with wind speed results from different algorithms, wind vectors based on commonly-used CMOD4 algorithm showed good agreement with those derived by other algorithms such as CMOD_IFR2 and CMOD5, particularly at medium winds from 4 to $8\;ms^{-1}$. However, apparent discrepancy appeared at low winds (< $4\;ms^{-1}$). This study also addressed an importance of accurate wind direction data to improve the accuracy of wind speed retrieval and discussed potential causes of wind retrieval errors from SAR data.

• Nutrition Research and Practice
• /
• v.4 no.4
• /
• pp.323-331
• /
• 2010

The aim of this study was to analyse effects that the degree of depression have on the life style variables, nutrient intake, iron indices and pregnancy outcome. Subjects were 114 pregnant women who were receiving prenatal care at a hospital in Seoul. We collected data for general characteristics and lifestyle variables from general survey instrument and for depression score from the questionnaire on depression. Dietary intakes of subjects were estimated by 24 hour dietary recall method. Also we analysed iron indices and pregnancy outcomes. We classified subjects by 10 point, which was the average depression score, into two groups [Low depression score group (LS) : High depression score group (HS)]. As to the intakes of total calcium, plant-calcium, plant-iron, potassium, total folate and dietary folate, LS group was far higher than HS group (P < 0.05, P < 0.05, P < 0.01, P < 0.001, P < 0.05, and P < 0.01, respectively). As to pre-pregnancy alcohol drinking, LS group had 41.9% in non-drinker, which was far higher than 28% in HS group in non-drinker (P < 0.05). As for drinking coffee during pre-pregnancy, pregnant women who don’ drink coffee in LS group took 43.6%, which was higher than 38% in HS group (P < 0.01). Regarding delivery type, the cesarean section in LS group (18%) was significantly lower than that in HS group (45%) (P < 0.01). Bivariate analysis showed that birth weight was significantly associated with the gestational age (P < 0.01). The pregnant women with higher depression score tended to have undesirable life habit, which might affect negative pregnancy outcomes. A better understanding of how depression and intake of nutrients work together to modulate behavior will be benefit nutritional research.

• Korean Institute of Interior Design Journal
• /
• v.24 no.3
• /
• pp.121-128
• /
• 2015

As a neighboring country belonged to the same cultural sphere with the Northeast Asia, China is recently emerging as a center of the world's economy. The social transformations caused by the rapid economic growth are bringing changes in the Chinese housing culture and thus, it is considered that the identification of a user's need concerning a new housing space and social and cultural understanding on China are necessary. Accordingly, this research intended to conduct the basic research on the Chinese housing space design by observing the small apartment users in Shanghai area in terms of not only the tangible element of the residential space type but also the intangible elements such as lifestyle, values, behaviors, etc. The research range was limited to the kitchen area at the center of a house as a place where the exchanges among the family members are most frequently occur, and the research was carried out in the following methods. First, the effective user research method for the analysis of the Chinese small apartment kitchen users was studied through the literature investigation. Second, the 6 families of a research target were selected focused on the small apartments in Shanghai, China and the user research was performed using three methods of User observation, Video ethnography, and Contextual inquiry. Third, the research results were analyzed focused on the flow of human traffic in the kitchen area and user's behaviors. What were identified as a result take account of the human traffic movements in the kitchen areas around the sink-counter-cook top, cooking behaviors and meal areas outside of the kitchen. Through this, the need for the effective organization of the sink-counter-cook top, arrangement of meal area, and placement of storage by section for the kitchen space of China were drawn based on the understanding of the cooking process, and it was identified that such results require comprehensive understanding of Chinese housing culture.

• Journal of Korea Multimedia Society
• /
• v.18 no.11
• /
• pp.1419-1426
• /
• 2015

Distinguishing border between news and advertising is disappearing. Traditional journalism considered editorial part deals news and ad part handle commercial messages. But now this classification is meaningless. Current news consumers do not separate advertising content and non-advertising content. In Korea, making fake news or paid news pages is becoming social problem. Fake news uses various camouflages to pretend to be real news. This paper descriptively analyzed Korean fake news cases and suggested some guidelines for publishing news. We analyzed 3 major newspaper web sites from July to September, 2014. These three newspapers publish section pages everyday containing fake news or sponsored news. Totally more than one thousand articles were selected for content analysis. We coded the numbers of fake news, day of the week, the rate of sponsored news, average fake news publication number per pages, the conformity between news and advertising, and the type of fake news. We also coded the number of sponsored news article in day sections. We used method of comparing the advertising contents and news articles. As a result, 24.8% of news article were published for the advertising sponsors. Advertorial or fake news were sometimes arranged same pages the same day. We coded the conformity between same advertising and news content. More than 60 percent (60.9%) of fake news match with their sponsors. PR style of fake news is top and advertising type of fake news is the lowest.

• Herbal Formula Science
• /
• v.25 no.4
• /
• pp.499-508
• /
• 2017

Objectives : Skeletal muscle atrophy occurs in response to a variety of conditions. The unloading to muscle occurs clinically in limb immobilization, bed rest, spinal cord injury and peripheral nerve damage, resulting in significant loss of muscle mass and force production. Muscle disuse is accompanied by an increase in apoptotic signaling, which mediates some of the responses to unloading in the muscle. In this study we tested the hypothesis that Daeyeoung-jeon extract would improve muscle recovery after reloading following disuse. Method : Twenty young male Sprague-Dawley rats were used for the studies. The hindlimb immobilization was performed with casting tape to keep the left ankle joint in a fully extended position. No intervention was performed on the right leg and used as intact region. The Rats in Daeyeoung-jeon treated group (DYJ) were orally administrated Daeyeoung-jeon water extract, and rats of Control group were given with saline only. After 2 weeks of immobilization, all animals were sacrificed, and the whole gastrocnemius muscles were dissected from both legs. The morphology of right and left gastrocnemius muscles in both DYJ and Control groups were assessed by hematoxylin and eosin staining. Moreover, to investigate the immobilization-induced muscular apoptosis, the immunohistochemical analysis of Bax and Bcl-2 was carried out. Results : Daeyeoung-jeon represented the significant protective effects against the reductions of the left gastrocnemius muscles weight and average cross section area to compared with Control group. The treatment with Daeyeoung-jeon extract significantly reduced the immunoreactivity of BAX and increased the immunoreactivity of Bcl-2 in gastrocnemius muscle compared with Control group. Conclusion : Daeyeoung-jeon has protective effects against immobilization-induced muscle atrophy by regulating the activities of apoptosis-associated BAX/Bcl-2 proteins in gastrocnemius muscle.

• Journal of Korean Ophthalmic Optics Society
• /
• v.3 no.1
• /
• pp.223-228
• /
• 1998

Glass films of $SiO_2-TiO_2-M_xO_y$ (M = Co, Cr or Cu) have been prepared on soda-lime-silica slide glasses by the chemical solution method using a spin-coating technique. Commercially available tetraethyl orthosilicate, titanium trichloride, and cobalt-, chromium- and copper-nitrates were used as starting materials. No crystalline segregations of $Co_3O_4$, $Cr_2O_3$ and CuO were observed by X-ray diffraction ${\theta}-2{\theta}$ scans. From the optical transmission analysis, cobalt existed as $ Co^{2+}$ in tetrahedral coordination, chromium as $Cr^{6+}$ in tetrahedral symmetry and copper as $Cu^{2+}$ in octahedral coordination. Films with a crack-free and no texture exhibited homogeneous interfaces between the films and the substrates along the cross-section.

• Journal of Advanced Marine Engineering and Technology
• /
• v.37 no.1
• /
• pp.40-46
• /
• 2013

Turbulent flow and heat transfer in a channel with a detached rib array have been simulated. The computations are based on the finite volume method with the SIMPLE algorithm. The forms of ribs considered in this study were rib with rectangular cross section, rib with groove, broken rib, and V-shaped rib. The ribs were deployed transverse or aligned $60^{\circ}$ to the main direction of the flow. Local heat transfer coefficients were obtained at various Reynolds numbers within the turbulent flow regime. Area-averaged data were calculated in order to compare the overall performance of the tested ribbed surfaces and to evaluate the degree of heat transfer enhancement induced by the ribs with respect to the smooth channel. The highest heat transfer occurred for the rib with groove which was aligned $60^{\circ}$ to the main flow direction. Performance factor was decreased with the increase of velocity, and it was found that the best performance factor was obtained in the low velocity region.