• Journal of the Korean Society of Manufacturing Technology Engineers
• /
• v.7 no.4
• /
• pp.14-20
• /
• 1998

This paper describes a computer-aided die design system of progressive die for making CPT grid. An approach to the development of the automatic design system is based on knowledge-based rules. The developed system is designed by considering several factors, such as grid geometry and punch profile. Grid, a key component of electronic gun, is formed through a sequence of many operations, among which the pilot piercing, beading, notching, bending, swaging and slotting etc. Using the developed system, design parameters are determined and output is generated in graphic forms. Therefore the developed system provides part drawing and the assembly drawing of die set.

• Journal of the Korean Academy of Clinical Electrophysiology
• /
• v.2 no.2
• /
• pp.51-59
• /
• 2004

The purpose of this study was to analyze. The effect of participation physical activities on health care patterns in the aged. The subject of the study was selected by multi-stage stratified cluster random sampling among the aged center and aged club to participate program whose age were 65 and over year old among inhabitant the Kwangju metropolitan area. The data were collected through a questionnaire adapted from Payne and Hahn's(1986) 'Understanding Your Health-A personal profile; Evaluating Your Health'. The pilot test was executed after the questionnaire was translated into Korean.

• Journal of Environmental Science International
• /
• v.10 no.1
• /
• pp.59-64
• /
• 2001

The effect of major operating parameters in spray drying sorber(=SDS) for automatic control for the simultaneous removal of acidic and organic gaseous pollutants from solid waste incinerator was performed. The field experiment was carried out in pilot scale test for the quantification of major operating parameters of hydrophilic and the hydrophobic pollutants. The removal efficiencies of $SO_2$and HCI in the 5wt% slurry condition were being increased with the increase of the stoichiometric ration which is the molecular ratio of lime to the pollutant concentration, and with the decrease of inflow flue gas temperature in the pilot SDS reactor. The removal efficiency along the height of spray drying sorber was closely related to the temperature profile, and more than 90% of total removal efficiency was achieved in an absorption region. For the removal of acidic gas the optimum operating condition considering the economics and a stable operation is the 5wt% of slurry concentration, 1.2 of stoichiometric ratio and 25$0^{\circ}C$ of inflow flue gas temperature. For the organic gases of benzene and toluene the removal efficiencies were 20-60% which is much lower than that of acidic gas. The best removal efficiency was obtained at 1.5 of stoichiometric ratio and 25$0^{\circ}C$ of inflow flue gas temperature. The organic\`s removal efficiency along the height of spray drying sorber was quite different from that of acidic gas, that is, more than 60% of the total removal efficiency for benzene and 90% of the total removal for toluene were achieved in the dried adsorption region, which was formed at the lower or exit part of the reactor.

• Applied Chemistry for Engineering
• /
• v.10 no.3
• /
• pp.467-476
• /
• 1999

This paper analyzed the behavior of fixed-bed catalytic reactor (FBCR) which synthesizing maleic anhydride(MA) from the selective oxidation of n-butane. The behavior of FBCR describing convection-diffusion-reaction mechanism is examined by using two-dimensional pseudohomogeneous plug-flow transient model, with the kinetics of Langmuir-Hinshelwood type. Prediction model is composed by optimum parameter estimation from temperature profile, yield and conversion of single FBCR on operating condition variations of Sharma's pilot-plant experiment. A double FBCR with same yield and conversion for single FBCR generated a $8.96^{\circ}C$ lower hot spot temperature than a single FBCR. We could predict parametric sensitivity according to the variation of possible operating condition (temperature, concentration, volumetric flow of feed reactant and coolant flow rate) of single and double FBCR. Double FBCR showed the behavior of more operating range than single FBCR. Double FBCR with nonuniform activities could assure safety operation condition for the possible variation of operating condition. Also, double FBCR had slightly higher than the single FBCR in conversion and yield.

• Korean Journal of Food Science and Technology
• /
• v.15 no.4
• /
• pp.392-398
• /
• 1983

A pilot single-screw food extruder was constructed, and its mechanical properties and product characteristics were investigated by using corn grits. The screw rotational speed was varied and the changes in temperature profile of the barrel for the start-up period of operation were measured. The rate of heat generation for the start-up period was affected by the screw speed and feed rate. The screw speed resulted in a great influence on the estimated dough viscosity. The changes in the dough viscosity could indicate the on-set of termoplastic reaction in the barrel. The expansion ratio during the start-up period mainly depended on the barrel temperature and the degree of thermoplastic reaction in the barrel. The barrel temperatures for the gelatinization and burning of corn grits depended on the screw speed as well as the feed rate.

• Korean Chemical Engineering Research
• /
• v.45 no.6
• /
• pp.582-590
• /
• 2007

In view of the analysis of the phenomena and the prediction of the performance, mathematical modelling and simulation of a high temperature pilot reactor for water gas shift reaction (WGSR) has been carried out. Multiscale simulation incorporated computational fluid dynamics (CFD) technique, which has the capability to deal with the reactor shape, fluid and energy transport with extensive degree of accuracy, and process modeling technique, which, in turn is responsible for reaction kinetics and mass transport. This research employed multiscale simulation and the results were compared with those from process simulation. From multiscale simulation, the maximum conversion of was predicted approximately 0.85 and the maximum temperature at the reactor was calculated 720 K, resulting from the heat of reaction. Dynamic simulation was also performed for the time transient profile of temperature, conversion, etc. Considering the results, it is concluded that multiscale simulation is a safe and accurate technique to predict reactor behaviors, and consequently will be available for the design of commercial size chemical reactors as well as other commercial unit operations.

• The Journal of the Korean dental association
• /
• v.55 no.11
• /
• pp.766-776
• /
• 2017

This clinical study was conducted to evaluate the clinical effects of a concave neck of external connection type implant fixture designed for platform switching on the peri-implant tissue responses. Two types of implants with different neck designs were implanted in 20 patients. For the experimental group, the bioseal(BS) implant fixtures with 's' shaped concave profile on the neck were used, and non-bioseal(NBS) implant fixtures with a straight profile on the neck were used as control(Total of 40 implants, NBS: n = 19, BS: n=21). During the one-year period after implant placement, implant survival rate, marginal bone resorption, bleeding, plaque, and complications were evaluated. The survival rate of NBS and BS group was 94.74% and 90.48%, respectively. There was no significant difference on marginal bone resorption, bleeding and plaque between the two groups (P>.05). Within the limits of the present study, implants with a concave neck design showed similar clinical results to implants with a straight neck design on the peri-implant tissue responses. Longitudinal clinical studies are necessary to confirm more effective clinical results.

• Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
• /
• 2004.04a
• /
• pp.449-454
• /
• 2004

Nowadays, flood hazard maps have been generated to minimize the loss of human lives due to flooding domestically. To generate the flood hazard maps, LiDAR data have mainly been used to provide topographic data. The LiDAR data requires, however, relatively higher cost and processing time. Therefore, the needs of validating possible use of topographic maps as an alternative source of LiDAR, which have been already existed from the NGIS project over the nation, has been raised. In this background, this study has generated a DEM over City of Kuri as a pilot study using conventional 1:1,000 and 1:5,000 topographic maps emphasizing the linkage of river profile with breakline processing algorithm to build the essential topographic data as accurate as possible. The results showed that the RMSE from topographic maps and LiDAR were 3.49 and 2.282 meter, respectively. Further study needs to be made to decide possible use of topographic maps instead of LiDAR including more easier updating of topographic maps to support flood map generation. In addition, 1:1,000 topographic mapping, which is limited to the urban areas so far, needs to be extended to the river areas.

• Journal of Environmental Science International
• /
• v.10 no.6
• /
• pp.417-422
• /
• 2001

The vertical structure of atmosphere was observed In investigate the variation of surface ozone concentration by vertical downward mixing of residual ozone in the atmospheric boundary layer at the Busan coastal area. Airsonde and pilot balloon measurements were made at Gamcheondong and the Kimhae airport for April 26~27, 1996. The vertical potential of potential temperature showed a residual layer between 510m and 1800m from 2100LST April 26 to 0900LST April 27. The downward mixing of ozone in the residual layer of the atmospheric boundary layer was confirmed from vertical profile of mixing ratio near 600m in the morning. The thickness of the sea breeze layer was 900m at 1500LST April 26. Thereafter, it become to be lowered with time A low level jet was measured near 900m at 0300LST on April 27 from a pibal measurement. Early morning sharp increase of surface ozone concentration at the Busan coastal area was caused by vertical downward mixing of ozone concentration rather than by photochemical reaction In the atmospheric boundary layer.

• Ocean and Polar Research
• /
• v.23 no.3
• /
• pp.265-277
• /
• 2001

This paper aims at overviewing Korean fisheries profile with a view on why Korean fisheries need marine ranching program as a new fisheries paradigm - a community-based co-management approach and drawing some policy implications from the advanced experience in fisheries. The aims of community-based co-management approach as a planned approach can be set out under the planning objectives of efficiency and equity. In this context Tongyeong marine ranching program is an important government-sponsored pilot enterprise. Experiences in the advanced fisheries such as Canadian Snow-Crab case suggest that in order to be successful for marine ranching be successful it is necessary that (i) there should be high-value species, (ii) property right should be established, (iii) there should be the reasonable number of participants involved, (iv) the participants and the government should be able to share resource enhancement/management/utilization responsibilities and associated fisheries management expenses. Among these, management cost sharing based on the practical partnership between fishing communities and government is of particular importance because the government must have a full responsibility for all ranching program expenditure unless revenues sufficient to guarantee reasonable income and to share management cost are generated from the ranching business.