• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.22 no.3
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• pp.421-428
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• 2013

The current vibration reduction methods for positioning systems lead to either complicated motion or the need for additional hardware when the positioning systems carry out frequent short-distance movements. This paper proposes a simple yet efficient vibration reduction method for positioning systems subjected to frequent short-distance movements. The essence of the proposed method is the trapezoidal or triangular velocity profiles, whose acceleration/deceleration rates are designed to be related to the natural frequency of concern. The combined use of the proposed method and the input shaping method is also proposed for the possible application to multi-mode systems. Experiments are performed to validate the proposed method. The simulation and experiments prove that the proposed method is of great use for residual vibration reduction in positioning systems subjected to frequent short-distance movement.

• Fisheries and Aquatic Sciences
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• v.26 no.8
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• pp.514-523
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• 2023

The visible threshold of Oreochromis niloticus responded to high light intensity under short wavelengths, whereas the response to low light intensity under long wavelengths was low, with a minimum visual threshold of 574 nm of LED lights. Movement distance of O. niloticus was dropped at 31℃ and increased abnormally at 37℃ under natural light. Comparing movement distance under red (622 nm) and green (518 nm) lights of LED, movement distance and swimming speed under red and green lights were higher than under natural light. However, the movement distance decreased rapidly at 31℃ under red light and lowest at 33℃ under green light. After that, there was a tendency to adapt to high water temperatures gradually. Consequently, red and green lights may be recommended for O. niloticus's aquaculture because the red and green lights have a positive effect on growth performance, survival rate, and metabolism, as shown in previous studies. It is necessary to control the water temperature below 32℃ because abnormal behavior above 32℃ revealed under red and green LED lights and natural light.

• PNF and Movement
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• v.8 no.2
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• pp.57-67
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• 2010

Background and Purpose : Many Physical therapist are inclined to communicate less effectively each other because they hardly use the standard terminology. The purposes of this case report are (1) to apply ICF-based documentation in evaluation (2) to submit the strategy of intervention process to improve the ability of walking short distance of the client who has post-stroke. Description : The client was 44-years-old man with hemiplegia who was in 1 month post-stroke problems were diagnosed while applying the ICF core set. The goals agreed with client were independently walking short distance, stairs and obstacles. To come up with the intervention strategy, hypothesis was set and 4 weeks of intervention was carried out after proposing the short goal and detailed purpose. Outcome : The client's performance in walking short distance and confidence were increased after impairment focused intervention, that are improved in walking velocity, endurance, supporting ability in lower limbs, rhythmical movement in upper limbs and the coordination of both limbs. Activities focused intervention also enhanced the ability in climbing steps and walking around obstacles. Conclusion : The decided hypothesis and goal that are to solve the problems the client faced were remarkably meaningful.

• Physical Therapy Korea
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• v.26 no.2
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• pp.16-23
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• 2019

Background: High-heeled shoes can change spinal alignment and feet movement, which leads to muscle fatigue and discomfort in lumbopelvic region, legs, and feet while walking. Objects: This study aimed to identify the effects of different shoe heel heights on the walking velocity and electromyographic (EMG) activities of the lower leg muscles during short- and long-distance walking in young females. Methods: Fifteen young females were recruited in this study. The experiments were performed with the following two different shoe heel heights: 0 cm and 7 cm. All participants underwent an electromyographic procedure to measure the activities and fatigue levels of the tibialis anterior (TA), medial gastrocnemius (MG), rectus femoris (RF), and hamstring muscles with each heel height during both short- and long-distance walking. The walking velocities were measured using the short-distance (10-m walk) and long-distance (6-min walk) walking tests. Results: Significant interaction effects were found between heel height and walking distance conditions for the EMG activities and fatigue levels of TA and MG muscles, and walking velocity (p<.05). The walking velocity and activities of the TA, MG, and RF muscles appeared to be significantly different between the 0 cm and 7 cm heel heights during both short- and long-distance walking (p<.05). Significant difference in the fatigue level of the MG muscle were found between the 0 cm and 7 cm heel heights during long-distance walking. In addition, walking velocity and the fatigue level of the MG muscle at the 7 cm heel height revealed significant differences in the comparison of short- and long-distance walking (p<.05). Conclusion: These findings indicate that higher shoe heel height leads to a decrease in the walking velocity and an increase in the activity and fatigue level of the lower leg muscles, particularly during long-distance walking.

• Journal of Korean Society for Atmospheric Environment
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• v.14 no.5
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• pp.397-410
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• 1998

Tracer experiments were performed 4 times in December 1992 on the relatively flat terrain and nearby building area adjacent to the Taedok Science Town in Korea. Each experiment was continued for relatively short period of 1 or 2 hours with intermittent release of SF6 up to 2.07g/s at 10m height. Movement of tracer plume was tracked by a continuous tracer analyzer installed on an air monitoring van. Simulation with INPUFF was carried out to analyze and predict experiments. Measured profiles of tracer plume were narrow and sharp while predicted profiles by INPUFF were broad and slowly varied. Tracer plumes were detected at a short distance of 0.5 to 2.2 km mainly due to intermittent release and high value of lower detectable limit. Various experimental conditions were tested by INPUFF simulation in order to find desirable conditions. Higher wind speed and less variable wind direction could yield longer distance of plume tracking only when the lower detectable limit was sufficiently low. Distance of plume tracking was long and did not much depend on the lower detectable limit in stable atmospheric conditions.

• Journal of the Korean Geographical Society
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• v.28 no.1
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• pp.40-57
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• 1993

This paper aims to show the various aspects of migration in Kwangju merropolitan area, southwestern Korea, for a period of years 1980-1985. Migratory patterns are spatially extensive in countryside around Kwanfju, and due to high accessibility to the metropolitan area urban implosion emerges in the city. In Chonnam province where Kwangju is loca-ted, all cities and counties except for such in-dustrial areas as Yochon, and Kwangyang are experiencing population losses in terms of net migration by survival rate methods. Kwangju is the exceptionally one of in-migration areas in Chonnam, though its central part(Dong-Gu) is also an out-migrated area. Predominantly in-migration urban areas have high proportions of a student age group between 15-19 years, and that reflects the importance of the educational factor in migration analysis. The municipal authorities of Kwangju are planning to block the way of the middle sxhool students who live in the outskirts of Kwangju to entrance to high school in the city. Thant may stir up migrations into Kwangju for the elementary and middle school students, because the city id expected to provide educational opportunities higher and better than remaining Chonnam areas. Population of Kwangju would, therefore, grow as the students migrate into the city. The findings on the residential intra-city movement in selected 5 Dongs indicate that implications of a short-distance movement re noteworthy; neighbour to neighbour, and the nearest stop in the way from the outer Kwangju as well. Trends in a short-distance movement are in accord with Ravensteins's "law of migra-tion". But in casw of the inter-provincial migra-tion to Kwangju, the number of in-migrants from remoter Seoul is more than that from nearer Chonbuk province. Therefore it supports the fact that the movement between capital region and far off local cities overcomes a distance barrier. The temporary mobility for a day has been increased as the standard of living has improved and it reaches a peak on weekend or on con-secutive holidays. The number of temporal movers to Kwangju from capital region and Yongnam area, southeastern Korea has a greatincrease in terms of the frequency of the passengers' mobility, in particular on Myongjol(the ethnic and traditional festival day) in com-parison with on weekdays. By comparison with two largest Myongjols, the number of movers is more on Chusok(The Full Moon festival on lunar August) than on Sol (lunar new year's day). Annual peak point of weekday movers appears in August because of summer vacation. But the lowest one appears in June, which is related to the busy farming season. A patients' move for medical services in on the increase with a change of living conditions. It is especially true in the industrial counties such as Kwangyang and Yochon. By way of conclusion, it should be pointed out that one of the problems we face in survey of migration volume by the survival rate method is that the survival rate somtimes exceeds the value 1.0, in normal states of which should be under 1.0. it may be due to the shortcoming from the census statistics. We should not give therefore too much stress on the importance of migrations or moves as an element of changes in spatial pattern. In cinclusion, the results of the study show some geographic facts as the followings: 1. One of the outstanding phenomena in all types of movement is the seletivity of ages. The most important factors are related to education and employment. 2. Short-distance movement is carried out in accordance with Ravenstein's law, but in case long-distance movement, in-migration from capital region is prominent in spite of remoten-ces. The gravity between large cities such as Kwangju and Seoul, which has a frequent human movenent, causes urban implosion of small cities between those cities. 3. The temporary mobility for a day, in con-trast to that of permanent movement, is more related to transportation, and its volumes and annual variations are a large-scale. 4. Passengers' mobility is high in industrial cities. And the scope of patients' mobility is narrower than passengers'.

• Korean Journal of Materials Research
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• v.25 no.8
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• pp.403-409
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• 2015

Metastable phase characteristics of beta Ti alloys were investigated to consider the relationship of the microstructure and diffraction pattern in TEM. TEM analysis showed that the microstructure was mottled as a modulated structure, and the diffraction pattern was composed of spot streaks between the main spots of a stable beta phase with a specific lattice relationship. The modulated structure may be induced by short distance slip or atom movement during a very short interval of solution treated and quenched (STQ) materials. The athermal ${\omega}$ phase, which could be precipitated at low temperature aging, is also analysed by the metastable phase. The metastable phases including athermal ${\omega}$ phase had a common characteristic of hardened and brittle behavior because the dislocation slip was restricted by a super lattice effect due to short distance atom movement at the metastable state.

• Journal of Communications and Networks
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• v.15 no.1
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• pp.54-60
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• 2013

In this paper, a novel method called location-based delivery (LBD), which combines the short message service (SMS) and global position system (GPS), is proposed, and further, a realistic system for tracking a target's movement is developed. LBD reduces the number of short message transmissions while maintaining the location tracking accuracy within the acceptable range. The proposed approach, LBD, consists of three primary features: Short message format, location prediction, and dynamic threshold. The defined short message format is proprietary. Location prediction is performed by using the current location, moving speed, and bearing of the target to predict its next location. When the distance between the predicted location and the actual location exceeds a certain threshold, the target transmits a short message to the tracker to update its current location. The threshold is dynamically adjusted to maintain the location tracking accuracy and the number of short messages on the basis of the moving speed of the target. The experimental results show that LBD, indeed, outperforms other methods because it satisfactorily maintains the location tracking accuracy with relatively fewer messages.

• Proceedings of the Korean Society for Agricultural Machinery Conference
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• 1996.06c
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• pp.591-597
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• 1996

To straighten the path that farm machinery follows in paddy fields, it is necessary to measure and evaluate the tracks that these machines leave behind. However, there are no known methods for making such measurements and evaluations since it is difficult to accurately trace the paths that the machine make in paddy fields. Therefore, a measuring system has been developed which can accurately recored the path of a farm machinery in a field by measuring the horizontal straight-line distance from the side of the field to the machine. This system consists of a track subsystem on the machine and a range finder system. A measuring appraratus is installed on a flatcar which runs on rails over 50 m long at the side of the filed. The track subsystem uses a CCD camera to track the movement of the machine in the field which is following a lengthwise path. The range finder subsystem measures the distance that the measuring apparatus has traveled on the rails and the distance from the app ratus to the machine in the field. This system makes it possible to record the path that the machine travels. Even though differences in traveling distance arise between the measuring apparatus and the farm machine, these differences are detected by image processing , which allows the machine in the field to be located accurately. The short(0.05 second) time required for image processing is enough to follow an object . In the present study, this system was able to measure the path that a moving tractor makes. Even though a lag of up to 0.4 meters occurred, this system did not miss its target during operation of the track subsystem. Thus the path measuring system developed here is able to record vehicle paths automatically by following the movement of vehicles in the field and measuring the distance to them. It is expected to come into use in such applications as unmanned moving vehicle tests.

• Korean Journal of Ecology and Environment
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• v.48 no.2
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• pp.139-145
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• 2015

To investigate seasonal (summer and fall) daily movement of Brachymystax lenok tsinlingensis that inhabit in upper part of the Nakdong River, we attached radio tags to seven individuals (summer: BL1-2; fall: BL3-7) and monitored them at an interval of 2 h. The survey results revealed that the average movement distance per day (m) (${\pm}SD$) of B. l. tsinlingensis was $182.4{\pm}79.2m$, and most of the individuals migrated within 1 km as their habitat boundary. The maximum movement distance per day (m) and the home range (m) during summer season were $550.5{\pm}75.5m$ and $649{\pm}53m$, respectively, compared to $283.8{\pm}55.1m$ and $186{\pm}32m$ during fall season. From these findings, it can be inferred that B. l. tsinlingensis exhibits seasonal changes in the distance of daily movement; however, it generally covers short distances without leaving the habitat boundaries during both seasons. The seasonal daily movement of B. l. tsinlingensis established in this study is expected to be useful in preserving their population.