• Korean journal of food and cookery science
• /
• v.30 no.2
• /
• pp.139-145
• /
• 2014

This study investigated the physicochemical characteristics of processing type rice (Deuraechan) with brown rice and brown rice milling different yields (97.4, 96.0, 94.4 and 92.0%). In the results of proximate composition of rice flours with the different milling degrees, moisture contents were 12.92~13.07%, crude protein contents were 6.62~8.47%, crude lipid contents were 0.84~2.52%, crude ash contents were 0.51~1.17%, and crude fiber contents were 0.30~1.16%. The moisture contents were not significantly different. In the results of Hunter's color value of rice flours, L value was the highest in white rice, and a and b values were the highest in brown rice. Water binding capacity of rice flours was the highest in white rice 127.44%, but brown rice was the lowest 114.31%. As for amylogram properties, brown rice was the highest in the initial pasting temperature and temp. at maximum viscosity. However, white rice was the highest in maximum viscosity, viscosity at $50^{\circ}C$, breakdown and setback. In the results of different scanning calorimeter thermal properties of rice flours, brown rice was the highest in onset temperature, peak temperature and end temperature. The enthalpy (${\delta}H$) was the lowest in brown rice flour and the highest in white rice flour.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.32 no.6B
• /
• pp.390-401
• /
• 2007

This paper is to estimate and analyze the price elasticities of demand for mobile calls. We used the data for the period from January 2000 to December 2005 on a monthly basis. Data used are call minutes to mobile-originating(ML+MM), tariff for dispatch of fixed and mobile calls($P_L,P_M$), income(Y), and subscriber for mobile(N). In order to provide robust estimates of price elasticities, we have used two different econometric models. One is a Dynamic model which includes a lagged dependent variable and so can differentiate between long-un and short-run price elasticities using the Generalized Method of Moments(GMM). The other is a Box-Cox transformation model which is one of the most useful methods. Box-Cox transformation model shows that elasticity changes with the lapse of time. The results are as follow : Not including the price indices for land-originating, the estimate is overestimated otherwise. In Box-Cox transformation case, price elasticity had been steadily declining. And this result shows that mobile services had been changed necessities increasingly in Korea.

• Korean Journal of Optics and Photonics
• /
• v.17 no.1
• /
• pp.38-46
• /
• 2006

The stereoscopic camera based on the image formation principle on human eyes and the brain is designed and fabricated by using a CCD and two zoom lenses. As two zoom lenses are separated as 65 mm of the human ocular distance with the wide angle of view of $50^{\circ}$ and the variable convergence angle from $0^{\circ}$ to $16^{\circ}$, the camera can be operated by the similar binocular parallax as human eyes. In order to take the dynamic stereoscopic picture, a shutter blade for the selection of the left and right images in turns, an X-cube image combiner fur the composition of these two images through the blade, and a CCD with 60 frames per second are used.

• Applied Chemistry for Engineering
• /
• v.3 no.1
• /
• pp.111-118
• /
• 1992

The curing acceleration of epoxy/amine system was investigated by using differential scanning calorimeter(DSC), The epoxy, diglycidylether of bisphenol A (DGEBA) was cured with methylene dianiline (MDA) with or without accelerators. Two kinds of accelerators were tested for the study ; tris(dimethylaminomethyl)phenol (DMP - 30) and 3 - (3,4 - dichlorophenyl)-1, 1-dimethylurea (DIURON). Heats of reaction and glass transition temperatures ($T_g$) of the cured epoxy system were analyzed by DSC along with the estimation of activation energy by the dynamic DSC studies. It was found that DMP - 30 is more effective accelerator than DIURON which showed faster curing and lower activation energy.

• Fire Science and Engineering
• /
• v.13 no.2
• /
• pp.26-32
• /
• 1999

We had investigated combustion pro야$\pi$ies of rice bran dusts. Decomposition of rice bran d dusts with temperature were investigated using DSC and the weight loss according to t temperature using TGA in order to find the thermal hazard of rice bran dusts, and the p properties of dust explosion in variation of their dust with the same particle size. Using H Hartman's dust explosion apparatus which estimate dust explosion by electric ignition after m making dust disperse by compressed air, dust explosion experiments have been conducted by v varying concen$\sigma$ation and size of rice br뻐 dust. According to the results for thermodynamic stability of rice bran dust, there are little change of initiation temperature of heat generation 때d heating value for used particle size. But i initiation temperature of heat generation decreased with high heating rate whereas d decomposition heat increased with particle size. Also, the explosion pressure was increased as t the ignition energy increased and average maximum explosion pressure was 13.5 kgv'cnt for 5 BJ/60 mesh and 1.5 뼈Ie미 dust concentration.

• Journal of Adhesion and Interface
• /
• v.2 no.1
• /
• pp.18-22
• /
• 2001

Surface morphology of [poly(vinylidene fluoride)/poly(methyl methacrylate)] (PVDF/PMMA) was investigated on the basis of atomic force microscopy and differential scanning calorimeter measurements. The surface of (PMMA/PVDF) and (H14-PMMA/PVDF) blend films was fully composed with PVDF crystals. Although the difference of surface free energy between PMMA and PVDF is increased with increasing carboxyl group content in PMMA, however, in the case of (H24-PMMA/PVDF) blend film surface, the existence of aggregated H-PMMA was observed. It was found that the degree of surface enrichment of the blend is more affected by the magnitude of intermolecular interaction than the surface free energy difference, Besides, the introduction of carboxyl group for miscible (PVDF/PMMA) blend decreased the miscibility in the blend.

• Membrane Journal
• /
• v.17 no.4
• /
• pp.359-368
• /
• 2007

The copolymer membranes, poly(vinylidene fluoride-hexafluoropropylene) (PVdF-HFP) were prepared by phase inversion method using as an additive with N,N-dimethylformamid as a solvent. The pores are generated during the solvent and non-solvent exchange process in the coagulation bath filled with non-solvent (distilled water). The highest porosity of the membrane was 60%. The surface and cross-section of the membranes was observed with a scanning electron microscopy (SEM). The mechanical property of the membrane was determined by using an universal testing machine (UTM). Tensile strength of measured membranes is presented the maximum 6.57 MPa at 30 wt% of PVdF-HFP.

• Journal of Korean Biological Nursing Science
• /
• v.23 no.3
• /
• pp.227-236
• /
• 2021

Purpose: The purpose of this study was to investigate the sleep duration, social jetlag (SJL), and subjective sleep disturbance according to the individual chronotype in rotating shift nurses. Methods: A total of 344 rotating 3-shift nurses (mean age 28.67 years) were recruited at one university affiliated hospital. They completed the following questionnaires, which were used to assess their chronotype and sleep: the morningness-eveningness questionnaire (MEQ), self-reported sleep duration of work days (SDW_shift) and free days (SDF_shift) in each shift (day [D], evening [E], night [N]), and sleep disturbance (Insomnia severity index, ISI). SJL_shift was calculated as the difference in midsleep (MS=sleep onset+1/2 sleep duration) between work days (MSW) and free days (MSF). Results: Subjects were divided into 3 chronotype groups according to the MEQ; morning (MG, 4.4%) intermediate (IG, 57.8%), and evening groups (EG, 37.8%). SDW_D was shortest (4.68 hr) and SDF_E was longest (8.93 hr) in the EG. SJL_D was longest in the EG (3.77 hr), and SJL_N was longest in the MG (7.37 hr). The prevalence of sleep disturbance was 33.3% (MG), 29.6% (IG), and 40.0% (EG), respectively, without any statistical significance. Conclusion: In order to improve the sleep of shift workers, it is recommended that the evening chronotypes should reduce the day shifts and the morning chronotypes should reduce the night shifts. We also propose a study to determine whether these shift assignments can improve the sleep in shift nurses.

• Proceedings of KOSOMES biannual meeting
• /
• 2006.11a
• /
• pp.71-74
• /
• 2006

Currently offshore fisheries are one of shrinking industries and fishermen are getting older. Moreover it is difficult to work fisheries for decreasing fishermen as the time goes. Two people per a boat work together at least for proper fisheries. If the unskilled fisherman boards on boat, it will make some troubles to speak each other and diminish the efficiency of working because one person should control the boat. So it need to study the remote control system for leasure and outboard engine that can control and work at the same time. The remote control system is consisted of engine revolution, steering gear and forward reverse neutral gear controls. These three controls are made by position and speed control using DC motor, and microprocessor is used to communicate and control the engine speed This system can be controled and worked alone and we tested the system at sea and confirmed that the system works properly.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.46 no.11
• /
• pp.1336-1342
• /
• 2017

The study examined and compared the physicochemical and characteristics of various rice brand varieties and private brand products on the market. The moisture content in the proximate composition of rice was 15.67~17.03%, crude protein content was 5.73~6.30%, crude lipid content was 0.38~0.95%, and crude ash content was 0.23~0.56 %. Ilmi and Ilpum had high moisture content, whereas Gosihikkari and Hopyeong had high crude protein content. In the Hunter's color value of rice flour, L value was 96.76~97.27, a value was -1.63~-0.63, and b value was 2.00~2.60. The WAI was 1.21~1.39, WSI was 0.63~0.93%, and amylose content was 14.63~20.86%, respectively; Gosihikkari and Ilmi showed the lowest values. The X-ray diffraction patterns of rice flours of all varieties showed an A shape. For the amylogram properties of rice flour, initial pasting temperature was $59.57{\sim}63.23^{\circ}C$, maximum viscosity was 569.00~718.67 B.U. (Brabender Units), breakdown was 303.00~423.67 B.U., and setback was 212.67~265.33 B.U.. For differential scanning calorimeter (DSC) of rice flour, onset temperature was $54.66{\sim}58.63^{\circ}C$, peak temperature was $65.87{\sim}68.14^{\circ}C$, end temperature was $73.37{\sim}75.54^{\circ}C$, and enthalpy was 1.98~2.95 cal/g. The rice varieties with high internal density and initial pasting temperature as well as low crude protein content, WAI, amylose content, and setback can be classified as good. Gosihikkari in Gyeonggi Province, Ilmi and Hopyeong in Jeollanam-do, and Samgwang in Chungcheongnam-do are among them.