• Journal of Biosystems Engineering
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• v.8 no.2
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• pp.62-68
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• 1983

This study was to examine the drying characteristics of barley and the effect of moisture content of barley on milling performance. A barley variety, Jogang, having 35.0% of initial moisture content was used for this experiment. Thermo-hydrostatic dryer which consists of blower, condensor, heater, humidifier, drying chamber and control box, etc., was used for the drying experiment. The change in the weight of a barley sample was continuously measured by means of the ring type load cell installed inside the drying chamber. Milling test runs the samples having the predetermined moisture content were taken from each drying test run. A laboratory type barley miller was used for the milling test. The results of the study are summarized as follows: 1. The drying constants (k) applied for the thin layer drying model, (M-Me)/(Mo-Me) = $Ae^{-kt}$ were 0.155, 0.259 and 0.548, respectively, at the three levels of drying temperatures, $40^{\circ}C$, $50^{\circ}C$ and $60^{\circ}C$. The drying constants complied with the Arrhenius Equation, K = Ko exp (-C/T), were determined as $Ko=1.901455{\times}10^8$ and C = 6563. 2. The laboratory milling test indicated that the highest milled and head barley recovery was resulted from the sample which was dryed at $40^{\circ}C$. In general, the increase in the drying temperature from $40^{\circ}C$ to $60^{\circ}C$ indicated a negative effect on milling yields. 3. Also, the sample having 15% M.C. presented the highest milled and head barley recovery among the five moisture content levels (12, 15, 18,21 and 24%).

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2012.05a
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• pp.722-725
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• 2012

In this paper, we design an 8-bit eSuse OTP (one-time programmable) memory based on a $0.35{\mu}m$ BCD process using differential paired eFuse cells which can sense BL data without a reference voltage and also have smaller sensing resistances of programmed eFuse links. The channel widths of a program transistor of the differential eFuse OTP cell are splitted into $45{\mu}m$ and $120{\mu}m$. Also, we implement a sensing margin test circuit with variable pull-up loads in consideration of variations of the programmed eFuse resistances. It is confirmed by measurement results that the designed 8-bit eFuse OTP memory IP gives a better yield when the channel width is $120{\mu}m$.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.13 no.11
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• pp.5458-5464
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• 2012

In LTE-Advanced that different networks coexist, it is considered that it is actually difficult to provide service continuity with a procedural and static control method applied to the existing voice service. This research suggests a resource management framework to support the service continuity effectively based on QoS support. In other words, as context information of mobile terminal and base station changes, set-up of related functions such as ISHO, cell selection, source allocation, load control, and QoS mapping is adapted; each function fits into the change, exchanges the process of reorganization, and interacts; these actions go toward to satisfy service continuity. For this aim, the sequence diagram between the function modules for supporting four kind of ISHO is described and then a scenario for ISHO is considered.

• Corrosion Science and Technology
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• v.17 no.2
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• pp.68-73
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• 2018

Substitution of hip and knee joints by CoCr alloys is in great demand due to their high wear resistance and good biocompatibility. Understanding of tribocorrosion in joint replacements requires study of variables such as coefficient of friction and the choice of a proper corrosive medium in wear-corrosion tests carried out in the lab. The objective of this study was to characterize tribocorrosion behaviour of CoCr alloy with low (LCCoCr) and high carbon (HCCoCr) contents in several corrosive media: NaCl, Phosphate Buffer Solution (PBS), and PBS with hyaluronic acid (PBS-HA). Tribocorrosion tests were carried out on a pin-on-disk tribometer with an integrated electrochemical cell. A normal load of 5N was applied on the alumina ball counterpart at a rotation rate of 120 rpm. Coefficient of friction (COF) was measured and tribocorrosion behaviour was characterized by in situ application of electrochemical techniques. HCCoCr alloy immersed in PBS-HA showed the best tribocorrosion behaviour with the lowest COF. In this case, in situ measurement of corrosion potential and the impedance data under wear corrosion process showed an active state while passive film was continuously destroyed without possibility of regeneration.

• Journal of Ocean Engineering and Technology
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• v.29 no.1
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• pp.34-44
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• 2015

A hydraulic tensile test machine (HSTM) is one of the devices used to obtain the flow stress of a material during high-speed elongation. This paper first describes some features of a newly built HSTM. The improvement histories of the upper and lower jigs, which are the most vital parts of the HSTM, are also presented. We have frequently witnessed test failures with 1st generation jigs and specimens due to slip between the jig and specimen. 2nd generation jigs provide more stable test results, but the use of a longer upper jig induces excessive vibration and consequently makes it difficult to attach an environment chamber. 3rd generation jigs have some advances in terms of the symmetric fastening between the upper jig and specimen, as well as an exemption from direct contact between the lower jig and specimen. The performance of an environment chamber is verified by high and low temperature tests. A high-speed displacement measurement system is introduced based on a high-speed camera and motion-tracking software with aid of a surface grid device for the specimen.

• Steel and Composite Structures
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• v.18 no.4
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• pp.853-871
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• 2015

Up to now, Japan has more than 200 corrugated steel web composite beam bridges which are under construction and have been constructed, and China has more than 30 corrugated steel web composite beam bridges. The bridge type includes the simply supported beam, continuous beam, continuous rigid frame and cable stayed bridge etc. The section form has developed to the single box and multi-cell box girder from the original single box and single chamber. From the stress performance and cost saving, the span range of 50~150 m is the most competitive. At present, the design mostly adopts the computational analytical method combining the spatial bar system model, plane beam grillage model and solid model. However, the spatial bar system model is short of the refinement analysis on the space effect, such as the shear lag effect, effective distribution width problem, and eccentric load factor problem etc. Due to the similarity of the plane beam grillage method in the equivalence principle, it cannot accurately reflect the shearing stress distribution and local stress of the top and bottom plates of the box type composite beam. The solid model is very difficult to combine with the overall calculation. Moreover, the spatial grid model can achieve the refinement analysis, with the integrity of the analysis and the comprehensiveness of the stress checking calculation, and can make up the deficiency of the analytical method currently. Through the example verification of the solid model and spatial grid model, it can be seen that the calculation results for the stress and the displacement of two models are almost consistent, indicating the applicability and precision of the spatial grid model.

• Journal of KIISE:Software and Applications
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• v.32 no.4
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• pp.258-267
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• 2005

We propose the ubiFloor system to track and recognize users in ubiquitous computing environments such as ubiHome. Conventional user identification systems require users to carry tag sensors or use camera-based sensors to be very susceptible to environmental noise. Though floor-type systems may relieve these problems, high cost of load cell and DAQ boards makes the systems expensive. We propose the transparent user identification system, ubiFloor, exploiting user's walking pattern to recognize the user with a set of simple ON/OFF switch sensors. The experimental results show that the proposed system can recognize the 10 enrolled users at the correct recognition rate of $90\%$ without users' awareness of the system.

• Transactions of the Korean hydrogen and new energy society
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• v.20 no.3
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• pp.202-207
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• 2009

A 75kW MCFC stack with the reactive area of 9,600cm$^2$ has been operated and validated in Boryeong thermal power plant. The 75kW MCFC stack was installed at the end of November 28, 2008 and started initial operation on December 23, 2008 after pretreated for about 20 days. At initial load operation, the stack showed the Open Circuit Voltage of 137V, which approaches the theoretical value. At the early stage of rated power operation, the stack displayed the voltage of 104V at the current of 754A and reached the maximum generating power of 78.5kW DC. This stack has been operated for 2,890 hours until April, 2009. In addition, the operation time of rated power records 1890 hours. This Operating result is scheduled to be reflected the design of l25kW stack.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.32 no.8
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• pp.82-90
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• 2004

The mechanical characteristics of three types of core with two-dimensional isotropic patterns-triangular, hexagonal and starcell-were studied in applications to sandwich structures. The Young's modulus and shear modulus were calculated for the three core types in the direction normal to the faces. The compressive buckling strength and shear buckling strength were calculated by modeling each cell wall of the core as a plate under compressive or shear load. To verify this model, tests were conducted on scaled specimens to measure the compressive buckling strength of each core. The bending flexibilites of the three cores were also studied. Compliances for the three cores were measured using biaxial flexural tests. The three isotropic core patterns exhibited distinct characteristics. In the direction normal to the faces, all three cores had the same stiffness. However, the starcell core exhibited high flexibility compared to the other cores, indicating potential for application to curved sandwich structures.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.34 no.11
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• pp.18-25
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• 2006

Unsteady aerodynamic force measurements were carried out in order to investigate the effects of phase difference of a dragonfly-type model with two pairs of wing. A load-cell was employed to measure the aerodynamic force generated by a plunging motion of the dragonfly-type model. The dragonfly-type model has a dynamic similarity with real one, and incidence angles of fore- and hind-wing are 0° and 10°, respectively. Other experimental conditions are as follows: The freestream velocity was 1.6 m/sec and corresponding chord Reynolds number was 2.88×103, and phase differences of fore- and hind-wing were 0°, 90°, 180° and 270°. The variation of aerodynamic coefficients during one cycle of the wing motion is presented. Results show that the lift is generated during the downstroke motion and the drag generated during the hind-wing‘s downstroke motion with the lift generation.