• 한국전산유체공학회:학술대회논문집
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• 2008.03b
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• pp.142-143
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• 2008

In the present work, high-speed video images of the ground take-off flight of a live butterfly were captured and their dynamic motions during the first full-stroke were analyzed. To capture the dynamic images of the take-off motion, the experimental setup consisted of a high-speed camera, a Xenon lamp as a light source and a transparent chamber of $15^W{\times}15^L{\times}17^H$ $cm^3$ in physical size. The ambient temperature and supplementary lighting devices were precisely controlled. The weight and wing span of the butterfly tested in this study was 104 mg and 63.14 mm, respectively. The ground take-off images were captured with 4000 fps with a spatial resolution of (1024${\times}$512) pixels. The period of the first full-stroke was 80.5ms and the flapping speed of downstroke was 2 times faster than that of upstroke. As a result, butterflies used the fling and near-clap motion to generate lifting force and an interesting take-off behavior of early pronation and downstroke was observed.

• International Journal of Automotive Technology
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• v.8 no.5
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• pp.543-553
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• 2007

It is becoming increasingly difficult for engines using conventional fuels and combustion techniques to meet stringent emission norms. The homogeneous charge compression ignition(HCCI) concept is being evaluated on account of its potential to control both smoke and NOx emissions. However, HCCI engines face problems of combustion control. In this work, a single cylinder water-cooled diesel engine was operated in the HCCI mode. Diesel was injected during the suction stroke($0^{\circ}$ to $20^{\circ}$ degrees aTDC) using a special injection system in order to prepare a nearly homogeneous charge. The engine was able to develop a BMEP(brake mean effective pressure) in the range of 2.15 to 4.32 bar. Extremely low levels of NOx emissions were observed. Though the engine operation was steady, poor brake thermal efficiency(30% lower) and high HC, CO and smoke were problems. The heat release showed two distinct portions: cool flame followed by the main heat release. The low heat release rates were found to result in poor brake thermal efficiency at light loads. At high brake power outputs, improper combustion phasing was the problem. Fuel deposited on the walls was responsible for increased HC and smoke emissions. On the whole, proper combustion phasing and a need for a well- matched injection system were identified as the important needs.

• International Journal of Automotive Technology
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• v.7 no.3
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• pp.237-244
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• 2006

Limited and nonlimited emissions of scooters were analysed during several annual research programs of the Swiss Agency of Environment Forests and Landscape(SAEFL, BUWAL). Small scooters, which are very much used in the congested centers of several cities are a remarkable source of air pollution. Therefore every effort to reduce the emissions is an important contribution to improve the air quality in urban centers. In the present work detailed investigations of particle emissions of different 2-stroke scooters with direct injection and with carburetor were performed. The nanoparticulate emissions with different lube oils and fuels were measured by means of SMPS, (CPC) and NanoMet. Also the particle mass emission(PM) was measured with the same method as for Diesel engines. It can be stated, that the oil and fuel quality have a considerable influence on the particle emissions, which are mainly oil condensates. The engine technology influences the (nano)particle emissions by: mixture preparation, mixture tuning, oil consumption, postoxidation, quality, condition and temperature of the catalyst. Since the particulate emission of the 2-S consists mainly of lube oil condensates the minimization of oil consumption stays always an important goal.

• The Journal of the Society of Stroke on Korean Medicine
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• v.13 no.1
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• pp.126-133
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• 2012

Object : The Purpose of this study is to report the clinical application of Korean traditional medicine on gait disturbance with arteriosclerosis of lower limbs. Methods : The patient in this case had been already treated by anticoagulation and varicose vein operation for subsiding and improving intermittent claduication and rest pain, but these methods didn't work on the patient. Although the patient was classified as TASC-II D, bypass operation couldn't be treated because of heart disease of the patient. We treated Korean traditional medicine such as acupuncture, moxibustion, Danggwisaeyeoktang. Results : After treatment, peak walking time was increased, rest pain occurrence was decreased and going up and down the stairs was improved. Conclusions : According to this study, Korean traditional medicine such as acupuncture, moxibustion, Danggwisaeyeoktang is effective for the cure of intermittent claudication and rest pain caused by arteriosclerosis of lower limbs.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2004.11a
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• pp.498-502
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• 2004

In a link-motion mechanism, numerous links are interconnected and each link executes a constrained motion at a high speed. Due to the complicated constrained motions of the constituent links, dynamic unbalance forces and moments are generated and transmitted to the main frame. Therefore unwanted vibration is produced. This degrades productivity and precise work. Based on constrained multi-body dynamics, the kinematic analysis is carried out to enable design changes to be made. This will provide the fundamental information for significantly reducing dynamic unbalance forces and moments which are transmitted to the main frame. In this work, a link-motion punch press is selected as an example of a link-motion mechanism. To calculate the mass and inertia properties of every link comprising a link-motion punch press, 3-dimensional CAD software is utilized. The main issue in this work is to eliminate the first-order unbalance force and moment in a link-motion punch press. The mass, moment of inertia link length, location of the mass center in each link have a great impact on the degree of dynamic balancing which can be achieved maximally. Achieving good dynamic balancing in a link motion punch press is quite essential fur reliable operation at high speed.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.9 no.2
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• pp.281-285
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• 2008

Die hobbing is one of the dieblock manufacturing methods of cold forging die, which makes the upper side of dieblock indented using master punch, hobb to produce impression not using cutting work. SKD11, alloy tool steel was used as the material of dieblock and stainless sheet metal was used as product material in cold forging work. The life span of the die was 6,000 strokes. In this research, the material of dieblock was changed into SKH51, the high speed tool steel and the product material was S45C, the carbon steel in the cold forging work. The life span of the die was 21,000 strokes, which is 350% of the life span of the die using the former method.

• Journal of Korean Society of Neurocognitive Rehabilitation
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• v.10 no.2
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• pp.27-34
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• 2018

The purpose of this study is to investigate the effect of task training for cognitive activation of upper extremity on upper limb function and activities of daily living and to suggest intervention in rehabilitation treatment. From January to February of 2018, nine stroke patients were arbitrated 30 minutes a day, five days a week, for four weeks. For the experimental group, the therapist has induced the group using the linguistic guidance to patients, so they utilize the cognition strategy. The control group conducted active exercises in a range of motion using the instruments and passive exercises in a range of motion to reduce the stiffness of joints and upper limbs. As muscle strengthening exercises, the patients were assigned to work on the biceps muscle of arm, triceps muscle of arm, and deltoid according to the individual patient's muscular strength level. For the experimental group, the MBI was improved by ten points at maximum, and K-AMPS motor skills showed the improvements of 1.0 logit at maximum, and processing skills showed improvements of 0.6 logits at maximum. In MFT, the maximum improvement was by two points. For the control group, MBI was improved by five points at maximum, and 0.2 maximum improvements were shown in K-AMPS' motor skills and 0.3 maximum improvements in processing skills. MFT showed no change. The conclusion is that the challenges to enable training for stroke patients give a positive impact on upper limb function and activities of daily living.

• Journal of Energy Engineering
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• v.11 no.2
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• pp.160-165
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• 2002

The heavy-duty LPG-fueled single cylinder engine was designed and developed as a fundamental equipment for analyzing combustion processes and emission performances. The cylinder head and the piston crown were modified to fire the LPG in the engine. The flywheel was also fabricated to minimize the vibration of the single cylinder engine. The size of bore and stroke of the tested engine are 130 mm and 140 mm, respectively. Compression ratios were varied 8 to 9 with different piston crown shapes. The developed single cylinder engine operates at 1,000 rpm for this work. The major conclusions of this work are; (1) the power of the developed engine was peaked at the condition of equivalence ratio 1.0 at three different compression ratios; (2) the power is slightly increased with the increase of compression ratio; (3) the optimum ignition timing is retarded with the increase of compression ratio ranged 2 to 10 crank angle.

• Journal of Advanced Marine Engineering and Technology
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• v.28 no.3
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• pp.482-492
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• 2004

Recently. the market trend for marine diesel engine has involved the lower running speeds. larger stroke/bore ratio and higher combustion pressure. Consequently, because of the flexible engine shafting system due to the larger mass. inertia and the more elasticity, the complicated coupled torsional-axial vibrations have occurred in the operating speed range. Also, the vibrations act as an excitation on the hull-structural vibration. To predict the vibration behavior with more accuracy and reliability. many studies have proposed the several kinds of method to calculate the stiffness matrix of crankshaft. However, most of these methods have a weak point to spend much time on three dimensional modeling and meshing work for crankshaft. Therefore. in this work. the stiffness matrix for the crankthrow is calculated using the energy method (Influence Coefficient Method, ICM) with the each mass having 6 degree of freedom. Its effectiveness is verified through the comparison with the stiffness matrix obtained by using the finite element method (FEM) and measured results for actual ships propulsion system.

• The Journal of Korean Medicine
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• v.30 no.4
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• pp.142-161
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• 2009

Objectives: There are many unknowns surrounding Jeong-Jo's death. To better understand Jeong-Jo's death, we closely inspected his medical records from the 20 days before his death in The Annals of the Chosun Dynasty (朝鮮王朝實錄) and Seungjeongwon Ilgi (承政院日記), Understanding medical treatment before death, we can correctly trace the cause of Jeong-Jo's death. Methods: According to The Annals of the Chosun Dynasty (朝鮮王朝實錄) and Seungjeongwon Ilgi (承政院日記), we examined his medical records between June 14 and June 28 of 1800, as to the change in chief complaint, cold and heat, thirst, syndrome differentiation, the opinions of Jeong-Jo, and the opinions of doctors, The original work, The Annals of the Chosun Dynasty and Seungjeongwon Ilgi were provided by NIKH (The National Institute of Korean History). The Korean translation of The Annals of the Chosun Dynasty was also provided by NIKH. Seungjeongwon Ilgi (original work written in Chinese characters) was directly translated into Korean by the study author. Results: 1. Jeong-Jo's is likely to have died of septicemia caused by an abscess on his back. 2. The cause of Jeong-Jo's death could be stroke due to hypertension, mental stress, and 'Wha (火) disease' Conclusions: The dominant view that Jeong-Jo was murdered by poison is not likely.