• Transactions of the Korean Society of Mechanical Engineers A
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• v.25 no.8
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• pp.1302-1307
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• 2001

This study identifies the major coupling path by examining the variation of the coupled acoustic modal frequencies and modes. A 1/2-size acryl compartment model is designed and manufactured for the measurement and analysis of coupled acoustic modes. Due to acoustic coupling, a new acoustic mode appears in a low frequency range. This coupling affects only longitudinal acoustic modes of compartment. Experimental result shows that the package tray holes contribute to the coupling much more than the back seat and hole size is an important design factor to control low frequency acoustic modes in the coupled system.

• Transactions of the Korean Society of Mechanical Engineers
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• v.19 no.1
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• pp.277-283
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• 1995

For the development of low NO$_{x}$ gas burners aimed for absorption chiller/heater unit, three proto type burners of different capacity (265000, 498000, and 664000 kcal/h) have been manufactured through a combustion method of step-by-step air injection. In order to characterize the overall features of the flame and the properties of the emission gas, the temperature of the flame and the concentration of NO$_{x}$ and CO were determined. The main factors in the design of burners (the area of primary air injection, the diameter of secondary air injection hole, fuel nozzle diameter) were observed to increase linearly with the scale-up of burner capacity. The flame temperature profiles of the burners were observed to be almost similar, irrespective of their capacity. However, as their capacity increased, the flame temperature slightly increased and the hot region of the flames moved to ward the flame tip along with the expansion to the direction of radius. From the proto type units, the amount of their NO$_{x}$ emission was determined to be around 25 - 30 vppm(3% )$_{2}$) and the CO emission was less than 19 vppm (3% $O_{2}$).TEX>).

• Journal of Korean Physical Therapy Science
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• v.22 no.1
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• pp.11-17
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• 2015

Purpose : The current study examines changes of static uprighting balance in the visual input characteristics. Method : Total 50 person(male 16, female 34) were participated in this study. They were tested with 'hole in the card' for identification of dominant eye's side, then they were divided 3 groups(both visual input group, dominant visual input group, and non-dominant visual input group). 3 groups were measured with Romberg test on the force platform device to compare the static uprighting balance characteristics ; moving distance, mean velocity, and sway area of the CoM(center of mass), during 20 seconds. Results : The results by one-way repeated measure ANOVA were as follows. In moving distance and mean velocity of CoM, non-dominant visual input group was unstable than dominant visual group and both visual input group(p<0.05). But, in sway area of CoM, significant difference was not existed statistically. Conclusion : These result can be applied to design the static uprighting balance program using visual input mediation.

• The Journal of Korea Robotics Society
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• v.8 no.4
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• pp.273-282
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• 2013

The purpose of this study was to investigate effect of robot-assisted hand rehabilitation(Amadeo(R)) on hand motor function in chronic stroke patients. This study used a single-subject experimental design with multiple baselines across individuals. Three chronic stroke survivors with mild to sever motor impairment took part in study. Each participants had 2 weeks interval of starting intervention. Participants received robot-assisted therapy(45min/session. 3session/wk for 6wks). Finger active range of motion(AROM) was assessed by Range of Assessment program in Amadeo(R), and test-retest reliability was verified using Pearson correlation analysis. To investigate effect of Amadeo(R), finger AROM was measured immediately after each sessions and Fugl-Meyer Assessment of Upper extremity, Motor Activity Log, Nine hole peg board test and Jebsen-Taylor hand motor function test were assessed at pre-post intervention. Results were analyzed by visual analysis and comparison of pre-post tests. The test-retest reliability of Range of Assessment was good(r=.99). After robot-assisted therapy, finger AROM of participant 1, 2, and 3 was respectively improved by 18%, 3.6%, and 6% each. Hand motor function of participant 1, 3 was improved on all four tests, but not effect in participant 2. Robot-assisted hand rehabilitation could improve finger AROM and effect on hand motor function in chronic stroke patients.

• Magazine of the Korean Society of Agricultural Engineers
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• v.17 no.4
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• pp.3991-4000
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• 1975

It is the aim of this study to investigate the influence of the factors in the sprayer nozzle for the travelling distance and to get nozzle design data in relation to the nozz1e with and without swirl plate. The factors of sprayer nozzle are composed of the spraying pressure, the helical angle of swirl plate, the helical groove depth of swirl plate, the distance of vortex chamber the slope of nozz1e cap, the curvature of nozzle cap and the hole diameter of nozz1e cap. The travelling distance and the size of sprayed particle are experimeted indoors by the factorial arrange-ment according to the 5 each level of the above factors. The results of this stupy are summarized as follows; 1. In the nozzle with swirl p1ate there were remarkable significance among factors each other, while without swirl plate were no significance. 2. The helical angle and groove depth in the nozzle with swirl plate were the highest effective factors. The effect of helical angle was very remarked in the quadratic curve with minium value. 3. The correlation betweenthe travelling distance and the sprayed particle size was no high and under 250 micron in the case with swirl plate, and there was higher correlation in the case without swirl plate. 4. The new ideal development of the swirl plate using of the most effective helical angle and groove depth will probably show the possiblities to make effective travelling distance over 8 meters and more over and to make average particle diameter under 300 micron.

• Journal of The Korean Society of Agricultural Engineers
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• v.54 no.2
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• pp.157-166
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• 2012

Most of the roads are paved with impermeable materials such as asphalt concrete and cement concrete, and in the event of heavy rainfall, rainwater directly flows into river through a drainage hole on the pavement surface. This large quantity of rainwater directly spilled into the river frequently leads to the flooding of urban streams, damaging lowlands and the lower reaches of a river. In recent years there has been a great deal of ongoing research concerning water permeability and drainage in pavements. Accordingly, in this research, a porous polymer concrete was developed for permeable pavement by using unsaturated polyester resin as a binder, recycled aggregate as coarse aggregate, fly ash and blast furnace slag as filler, and its physical and mechanical properties were investigated. Also, 3 types of permeable polymer block by optimum mix design were developed and rainfall runoff reduction effects by permeability pavement using permeable polymer block were analyzed based on hydraulic experimental model. The infiltration volume, infiltration ratio, runoff initial time and runoff volume in permeability pavement with permeable polymer block of $300{\times}300{\times}80$ mm were evaluated for 50, 100 and 200mm/hr rainfall intensity.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.19 no.4
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• pp.362-366
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• 2006

OLEDs(Organic Light Emitting Diodes) are attractive as alternative display components because of their relative merits of being self-emitting, having large intrinsic viewing angle and fast switching speed. But because of their relatively short history of development, much remains to be studied in terms of their basic device physics and design, manufacturing techniques, stability and so on. We investigated electrical properties of N, N-diphenyl-N, N bis (3-methyphenyl-l,1'-biphenyl-4,4'-diamine (TPD) and tris-8-hydroxyquinoline aluminum$(Alq_3)$ when their thicknesses were changed variedly from 3:7 to 5:5 of their thickness ratios. And we also studied properties of OLED depend on their deposition rate between $0.05{\sim}0.2$ nm/s.

• Journal of ILASS-Korea
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• v.17 no.2
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• pp.94-99
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• 2012

The characteristics of spray behavior and injected amount were studied with two types of nozzles for using in a compression ignition engine with dual fuel technology for construction machines. A penetration length of spray tends to shorten due to a decrease of injected amount of a diesel fuel with dual fuel engine application. In order to ignite the gaseous fuel premixed with air during intake process, a diesel fuel, which was compression ignited, needs to penetrate somehow similar depth compared with the case of a diesel fuel-only-injection. In this work, a nozzle with reduced hole diameter and increased number of holes was tested and demonstrated that, compared to diesel 100% case, its penetration lengths are comparable to 74% and 79%, respectively, of those of 100% and 50% supply of a diesel fuel with the baseline nozzle that has four holes and 30.4% increased diameter. This will presumably enhancement the combustion in a dual fuel engine. A design suggestion was also made in this work to achieve similar penetration length of spray with diesel 100% case to prevent combustion from being deteriorated in a dual fuel engine.

• The KSFM Journal of Fluid Machinery
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• v.12 no.5
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• pp.7-12
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• 2009

A nuclear fuel test loop(after below, FTL) is installed in the IRI of an irradiation hole in HANARO for testing the neutron irradiation characteristics and thermo hydraulic characteristics of a fuel loaded in a light water power reactor or a heavy water power reactor. There is an in-pile section(IPS) and an out-pile section(OPS) in this test loop. When HANARO is operated normally, the fuel loaded into the IPS has a nuclear reaction heat generated by a neutron irradiation. To remove the generated heat and to maintain the operation conditions of the test fuel, a main cooling water system(MCWS) is installed in the OPS of the FTL. The MCWS is composed of a main cooler, a pressurizer, two circulation pumps, a main heater, an interconnection pipe line and instruments. The interconnection pipeline is a closed loop which is connected to an inlet and an outlet of the IPS respectively. The MCWS is under a cold function test during a start-up period. This paper describes the system flow network analysis results of the flow control of a main cooling water system in the HANARO fuel test loop. It was confirmed through the results that the flow was met the system design requirements.

• Proceedings of the Korean Geotechical Society Conference
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• 1993.10b
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• pp.235-247
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• 1993

The 62 m span Olympic lee Hockey cavern in Gjovik, Norway, is located in jointed gneiss of average RaD = 70% and has a rock cover of only 25 to 50m, thus posing challenging design p problems. The investigations prior to construction included two types of stress measurements, cross-hole seismic tomography, special coe logging, Q-system classification and numerical modelling with UDEC-BB. Predicted maximum deformations were 4 to 8 mm; surprisingly small due to the high horizontal stresses recorded. Extensometer (MPBX) installations from the surface prior to construction, precision surface levelling and MPBX installed from inside the cavern give a combined measure of maximum deformations in the range 7 to 8 mm with the 62 m span fully e excavated, and three adjacent caverns for the Postal Services also completed.