• Journal of the East Asian Society of Dietary Life
• /
• v.10 no.1
• /
• pp.71-76
• /
• 2000

This study was carried out in order to investigated the degree of expansion, textural and sensory characteristics of Yukwa made from various cultivars of waxy rice, With 5 varieties of waxy rice and a nonwaxy rice, Yukwa were prepared by the standardized method that had been established optimum preparation conditions. Yukwa made from Shinsunchalbyeo and Whasunchal showed lower degree of expansion than Hangangchalbyeo and IR 29, but showed higher crispness and softer texture among tested waxy rice cultivars. Sensory characteristics of these cultivars showed high score in flavor, crispness and preference. Whasunchalbyeo and Shinsunchalbyeo were appropriate varieties for Yukwa preparation and they were both short grain in length/width. Whasunchalbyeo has the highest score of water uptake and reducing sugar content in Key word.

• Journal of Korean Society of Water and Wastewater
• /
• v.14 no.2
• /
• pp.164-173
• /
• 2000

Fluoridation of drinking water to a level of about 0.8mg/l (below 1.5mg/l) for reducing the incidence of tooth decay is recommended. However, concerns about potential problems of unknown effects and overdosing hinders the fluoridation. This study describes the work performed to obtain information on the behavior of fluoride under various conditions in the process of water fluoridation. Effects of water treatment chemicals, water treatment unit, and water distribution on water fluoridation were investigated at both lab and an actual water treatment plant. Residual fluoride concentration was not affected by lime and chlorine dosage up to 20mg/l. Flocculation with PAC slightly decreased the residual fluoride concentration as PAC dosage increased. Average fluoride concentration of 0.87mg/l at an intake basin was decreased to 0.83mg/l by sedimentation, 0.81mg/l by dual media(sand+anthracite) filtration, and 0.79mg/l by granular activated carbon filtration in the water treatment plant.

• Proceedings of the KSR Conference
• /
• 1998.05a
• /
• pp.265-272
• /
• 1998

In this paper, the intoner noise reduction for subway railroad vehicles was studied by improving transmission loss of carbody panels and side doors, and on-line tests were conducted to examine the exterior noise levels at various running conditions. Also the transmission loss for design candidates of the carbody specimen was measured in two reverberation rooms. From the results of the tests, side door gap is the most dominant factor affecting the Interior noise level of subway railroad cars with a sliding typed side door. The next one is revealed to transmission loss of a floor panel. To improve the transmission loss of the carbody, many activities were conducted such as, treatment of resilient and sound-absorbing materials and reducing the gap of the side door by adopting a brush and rubber, etc. The estimated interior noise level for modified car which is designed with improved carbody panels is lower than original car by about 5㏈.

• Smart Structures and Systems
• /
• v.20 no.5
• /
• pp.539-548
• /
• 2017

Thermoelasticity is a contactless technique for measuring stress distributions in structural elements stressed by dynamic loads. This work describes the characteristics, analyzes the main causes of uncertainty and illustrates a series of operative methods for reducing its effects. More specifically, the effects of the angle of view between the thermographic camera and the surface of the object are studied, along with those due to the heat transmission by conduction between the various parts of the thing being measured as a function of the stress frequencies. The analyses, both theoretical and experimental, are aimed at defining the operational limits and optimal measurement and test conditions in relation to the measurement uncertainty that is considered tolerable in the specific application.

• Proceedings of the KSME Conference
• /
• 2008.11b
• /
• pp.3001-3006
• /
• 2008

Recently, the internal combustion engines have focused on reducing both the CO2 emissions in order to cope with severe regulations for greenhouse effect. Therefore, various new technologies have been developed in many countries. Among them, the cooling system is spotlighted because it has great effect on fuel efficiency. However, the present engine cooling system is almost same as one of the 50 years ago. The needs for high performance and compact size make it important to improve engine cooling system, down-sizing and control method of coolant flow. Thus, low fuel consumption technology such as control and synthetic management of cooling system was necessary to satisfy with these needs. In this study, we applied electric thermostat to improve the fuel economy. The fuel consumption was compared after driving FTP-75 mode on both conditions which were with a conventional wax thermostat and with a electric thermostat. The coolant temperature of opening the electric thermostat is higher.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
• /
• v.13 no.12
• /
• pp.1275-1281
• /
• 2001

Aqueous polymer solutions are known to have small pressure reduction. Paraffin slurries are known to have high thermal capacity. Paraffin particles are mixed into an aqueous polymer solution to make a new heat transfer fluid having high thermal capacity but low pressure reduction. The heat transfer characteristics of the new slurry was tested in a circular tube having a constant heat transfer boundary condition. The new slurry was found to have high Nusselt numbers as well as high thermal capacity and low pressure reduction in the laminar flow. The trends of the Nusselt numbers along the heating test section were studied for various heating conditions.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
• /
• v.12 no.1
• /
• pp.69-77
• /
• 1998

The uninterruptible power supply (UPS) has become an integral part of modern computer and communication system to assure a continued and stable operation by providing an uninterruptible power to vital equipments. Various control methods have come to the fore in recent times with the advent of high frequency switching technologies. This paper describes the DSP control method for three phase UPS inverter which guarantees the sinusoidal output voltage under nonlinear load conditions. The proposed control scheme is verified by simulation and experiment.riment.

• The Transactions of the Korean Institute of Electrical Engineers
• /
• v.39 no.7
• /
• pp.653-667
• /
• 1990

Superconductor is consolidated, for required current capacity, with proper numbers of basic strands which are multifilamentary composites. Althouth superconductors are perfectly loss-free under DC conditions of current and field, AC losses occur under time-varying condition of the current and field. The AC losses are a controllable inherent characteristics of supercondectors. The AC losses dependent on the changing rate of current and field can be reduced by reducing the filament diameter. On the other hand, finer filament results in manufacturing cost increase. Therefore, in this paper optimization technique of superconductor for SMES is proposed from the viewpoint of AC loss reduction and manufacturing cost increase. The case study shows that the technique can be effectively used for the design of superconductor for SMES, appreciating the influence of various parameters related to superconductor itself and operating condition of SMES. As a result of the case study, it is confirmed that the technique is more effective for the design of superconductor for SMES for electric power power system stabilization rather then SMES for energy storage.

• The Transactions of the Korean Institute of Electrical Engineers
• /
• v.38 no.6
• /
• pp.401-415
• /
• 1989

A simple but accurate analytical model for the lateral channel electric field in gate-offset structured Lightly Doped Drain MOSFET has been developed. Our model assumes Gaussian doping profile, rather than simple uniform doping, for the lightly doped region and our model can be applied to LDD structures where the junction depth of LDD is not identical to the heavily doped drain. The validity of our model has been proved by comparing our analytical results with two dimensional device simulations. Due to its simplicity, our model gives a better understanding of the mechanisms involved in reducing the electric field in the LDD MOSFET. The model shows clearly the dependencies of the lateral channel electric field on the drain and gate bias conditions and process, design parameters. Advantages of our analytical model over costly 2-D device simulations is to identify the effects of various parameters, such as oxide thickness, junction depth, gate/drain bias, the length and doping concentration of the lightly doped region, on the peak electric field that causes hot-electron pohenomena, individually. Our model can also find the optimum doping concentration of LDD which minimizes the peak electric field and hot-electron effects.

• Journal of the Korean Institute of Landscape Architecture
• /
• v.23 no.2
• /
• pp.195-204
• /
• 1995

This study is focused on the groping for the alternative ways in order to prevent the various bad factors caused by the Inferior environment on the planted trees. In the reclaimed paddy field which is planned to make a housing site, for example, we are trying to catch the problem about the special feature of the unharmonized drainage. And the survey gives the suitable way of planting trees. This survey was carried out in the three different area and could notice some phenomena : There are a few different conditions for water supply int\ulcorner the soil according to the height of the land-filling from the original ground and the slope of the planting area. And the imporant factor of the drainage effect is not the soil texture itself but the depth of the filling land. As a result of this survey, the study shows the economic alternative for reducing the demage of the planting trees which is due to drainage system.