• International Journal of Fuzzy Logic and Intelligent Systems
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• v.14 no.2
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• pp.136-144
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• 2014

The existing conventional motion controller does not perform well in the presence of nonlinear properties, uncertain factors, and servo lag phenomena of industrial actuators. Hence, a feasible and effective fuzzy self-tuning proportional integral derivative (PID) and feed-forward control scheme is introduced to overcome these problems. In this design, a fuzzy tuner is used to tune the PID parameters resulting in the rejection of the disturbance, which achieves better performance. Then, both velocity and acceleration feed-forward units are added to considerably reduce the tracking error due to servo lag. To verify the capability and effectiveness of the proposed control scheme, the hardware configuration includes digital signal processing (DSP) which plays the main role, dual-port RAM (DPRAM) to guarantee rapid and reliable communication with the host, field-programmable gate array (FPGA) to handle the task of the address decoder and receive the feed-back encoder signal, and several peripheral logic circuits. The results from the experiments show that the proposed motion controller has a smooth profile, with high tracking precision and real-time performance, which are applicable in various manufacturing fields.

• Asian-Australasian Journal of Animal Sciences
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• v.17 no.2
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• pp.271-277
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• 2004

The purpose of this experiment was to study the feeding behavior and running speed under various feed deprivation lengths and social environments. Three trials were conducted. Trial 1: ten pigs were trained individually to run a course and eat their feed at the end of the course. The pigs were deprived feed for 1, 5, 10 or 20 h. Trial 2: 1. Two pigs ran and ate together. Both pigs had 5 h of feed deprivation before the run (D5). 2. Two pigs ran and ate alone, but both pigs had 5 h of feed deprivation before the run (S5). 3. Two pigs ran and ate together. Both had 1 h of feed deprivation before the run (D1). 4. Two pigs ran and ate alone and both pigs had 1 h of feed deprivation before the run (S1). 5. Two pigs ran together, one had 5 h of feed deprivation, and the other had 1 h of feed deprivation before the run (51). Trial 3: 1. On the 1st day 5 pairs of pigs had 5 h feed deprivation and could eat feed together at (B) point (D1). 2. On the 2nd day the pigs ran and ate alone at (B) point after 5 h of feed deprivation. Feed was obtainable (D2). On the 3rd to 6th days, the pigs ran in pairs after 5 h of feed deprivation and only the dominant pig ate feed at point (B). The inferior pig was chased back to room and fed there. This stage was continued for four consecutive days, d 3 to 6. In trial 1, the running speed of pigs increased with the length of feed deprivation until 10 h, then being stable afterwards. Total feeding time increased with the length of feed deprivation (p<0.001). Eating speed did not increase with the length of feed deprivation (p>0.05). In trial 2, nine of ten pigs in treatment D5 ran faster than those in S5. Seven of the ten pigs in treatment S1 ran faster than those in treatment D1. The pigs in treatment D5 had significantly higher feed intake (p<0.001) and eating speed (p<0.05) than the pigs in other treatments. In trial 3, there were significant differences on running speed between D1 and D6 (p<0.01) and between D2 and D1, D3, D4 and D5. The inferior pig ran faster in D2 but from 3 to 6 it was the dominant pig that showed the greatest speed in completing the whole course. The results demonstrated that the pigs with low feeding motivation may cause low running speed to feed and low feed intake of the neighbor when compared with pigs kept individually.

• Journal of Animal Science and Technology
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• v.57 no.12
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• pp.45.1-45.5
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• 2015

Background: Physical and chemical properties of feedstuffs can be changed by feed processing. Moreover, through various mechanisms, feed processing can affect growth performance and feed efficiency of swine, nutrition value of the feed. Weaning-to service-intervals (WSI), subsequent farrowing rates, and total-born litter sizes were determined by feed intake and metabolic state during lactation. Methods: A total of 20 sows (Landrace ${\times}$ Yorkshire) with an average body weight (BW) of 266.1 kg 4 d before farrowing were used to determine the effect of feed processing on the performance of lactating sows and their offspring. The following two dietary treatments were used: 1) Crumble diet (C); and 2) Mash diet (M). Ten replications were used for each treatment. Back fat thickness of sows was measured 6 cm off the midline at the 10th rib using a real-time ultrasound instrument at 4 d before farrowing, 1 d after farrowing, and during weaning. Sow BW were also checked at 4 d before farrowing, 1 d after farrowing, and during weaning. Fecal score of sows were assessed on d 14. Fecal score of piglets were observed on d 7, 15, and 24. Data were analyzed using t-test procedure of SAS (2014) with sow as experimental unit. Results: No significant (p > 0.05) difference was observed in the reproduction performance of sows between the two treatments. In addition, there was no significant (p > 0.05) difference in the growth performance of piglets between the two treatments. Fecal score of sows or piglets showed no significant (p > 0.05) difference either. Conclusions: In conclusion, different feed processing (mash or crumble) did not make any significant difference on the performance of lactation sow or their piglets.

• 한국기계연구소 소보
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• s.18
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• pp.29-35
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• 1988

When low sliding velocities in the boundary lubrication range are operating, irregular movements frequently occur which are a result of the stick-slip phenomenon. Such slide motions are undesirable in precision machine tools, particularly with feed back systems used in numerical and adaptive control machine tools. Accordingly, this paper reports analytical and experimental studies in the stick-slip characteristic of machine tool feeding system. The main conclusions of this study are as follows; The tendency towards stick-slip effects may be reduced by; 1). Reducing the drop in friction coefficient in the Stribeck curve(on the rising part of the friction characteristic at higher sliding speeds, the system is stable all the time) 2). Reducing the transition velocity by the use of a higher viscosity lubricating oil. 3). Increasing the stiffness(Damping)and reducing normal load(Sliding mass) Therefore, the Critical velocity is decided from the above conclusions and in designing of machine tool, feed rates(sliding velocity)must be design the more than critical velocity.

• Proceedings of the Korea Multimedia Society Conference
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• 2002.05d
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• pp.955-958
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• 2002

암호화를 위한 블록간의 연산 모드에서 어떤 연산 모드를 사용하는가에 따라 평문, 암호문 또는 키 추측 등에 많은 영향을 주게 된다. 본 논문에서는 여러 가지 블록 암호 연산 모드에 대해 알아보고, 다음 블록에 대한 키 정보의 암호화 강도를 효율적으로 높일 수 있는 RFB(Round key FeedBack) 운영 모드를 제안한다.

• The Korean Journal of Physiology
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• v.4 no.2
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• pp.19-24
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• 1970

Since the discovery of the muscle spindle by Hassall (1831), an intensive studies of its anatomical and physiological characteristics had been undertaken. Recent morphological studies of Boyd (1962) demonstrated that the muscle spindles have two different intrafusal muscle fibers, nuclear bag and nuclear chain fiber, and these intrafusal fibers are under independent motor innervation by ${\gamma}_1$ and ${\gamma}_2$ motor neurone. Neurophysiological studies of Hunt and Kuffler (1951) showed regulatory effect of ${\gamma}$ motor neurone upon the excitability of the spindle afferents. Harvey and Mathews (1961) observed the dynamic and static characteristics of the two different spindle afferents, the primary and secondary ending. Furthermore, Mathews (1962) postulated the functional existance of two kind of ${\gamma}$ motor neurones, namely, the dynamic and static fusimotor fiber. Recent report of Kim and Partridge(1969) pointed out that the descending vestibular signals had increased the slope of the length-tension relationship in stretch reflex; Kim (1967) demonstrated that the descending vestibular impulses act upon the stretch reflex loop through the ${\gamma}$ motor pathway. These experimental evidences from the morphological and neurophysiological studies on the muscle spindles support the concept that the stretch reflex action of the skeletal muscle operates as a negative feedback control system. The author had discussed the way by which the f system participates in the control of stretch relfex feed back system. that was taken for a prototype of posture and movement.

• 제어로봇시스템학회:학술대회논문집
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• 1988.10b
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• pp.794-797
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• 1988

G. Binnig and H. Rohrer introduced the Scanning Tunneling Microscope (STM) in 1982 and developed it into a powerful and not to be missed physical tool. Scanning tunneling Microscopy is a real space surface imaging method with the atomic or subatomic resolution in all three dimensions. The tip is scanned over the surface by two piezo translators mounted parallel (X-piezo and Y-piezo) to the surface and perpendicular to each other. The voltage applied to the third piezo (Z-piezo) translator mounted perpendicular to the surface to maintain the tunneling current through the gap at a constant level reflects then the topography of the surface. The feed back control loop for the constant gap current is designed using the automatic control technique. In the designing process of the feed back loop, the identification of the gap dynamics is very complex and has difficulty. In this research, using some suitable test signals, the system dynamics of the gap including the Z-piezo are investigated. Especially, in this paper, a system model is proposed for the gap and Z-piezo series system. Indicial response is used to find out the model. The driving voltage of the Z-piezo and the tunneling current are considered as input and output signals respectively.

• The Korean Journal of Community Living Science
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• v.17 no.1
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• pp.3-10
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• 2006

The purpose of this study was to analyze leadership competency in the rural leader roles. The data were derived from 317 leaders in 97 rural communities by questionnaire. SPSSWIN/ver10 was adopted t-test and IPA (Importance-Performance Analysis) methods employed. The major findings of this study were as follows; Rural leaders should concentrate on developing coaching/feed back, program management skills, and presentation skills. Administrative head of village should pay attention to benchmarking, brand development and conflict resolution rather than resident management, service knowledge, and making relationships. Leaders of village development council should concentrate on brand development, benchmarking, and educating residents. Head of women's organizations should concentrate on developing assessments, educating residents, and resolving conflict skills, whereas members of Samaeul organization should try to concentrate on program management, coaching/feed back and presentation skills. Rural leaders showed different leadership competency by the IPA. Therefore, this study suggested that leadership education for rural leaders should consider leadership competency.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.8 no.3
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• pp.71-82
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• 2009

As a solution to spectrum under-utilization problem, Cognitive radio (CR) introduces a dynamic spectrum access technology. In the area, one of the most important problems is how secondary users (SUs) should choose between the available channels, which means how to achieve load balancing between channels. We consider spectrum load balancing problem for CR system in frequency domain and especially in time domain. Our objective is to balance the load among the channels and balance the occupied time length of slots for a fixed channel dynamically in order to obtain a user-optimal solution. In frequency domain, we refer to Dynamic Noncooperative Scheme with Communication (DNCOOPC) used in distributed system and a distributed Dynamic Spectrum Load Balancing algorithm (DSLB) is formed based on DNCOOPC. In time domain, Spectrum Load Balancing method with QoS support is proposed based on Dynamic Feed Back theory and Hash Table (SLBDH). The performance of DSLB and SLBDH are evaluated. In frequency domain, DSLB is more efficient compared with existing Compare_And_Balance (CAB) algorithm and gets more throughput compared with Spectrum Load Balancing (SLB) algorithm. Also, DSLB is a fair scheme for all devices. In time domain, SLBDH is an efficient and precise solution compared with Spectrum Load Smoothing (SLS) method.

• Journal of the Korean Magnetics Society
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• v.22 no.2
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• pp.45-48
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• 2012

Feed-back type 3-axis flux-gate magnetometer using Co-based amorphous ribbon (Metglass$^{(R)}$2714A) was constructed in this work. Measuring range of magnetic field and frequency were ${\pm}100\;{\mu}T$ and dc~10 Hz respectively. For the interface to computer, microcontroller and 24 bit ADC (Analog to Digital Converter) were employed and resolution of digital output was 0.1 nT. Magnetometer noise of analog output was 5 pT/$\sqrt{Hz}$ at 1 Hz. Digital output of the magnetometer showed linearity of $1{\times}10^{-4}$ and the offset drift was smaller than 0.2 nT during 1 h.