• Journal of the Korean Operations Research and Management Science Society
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• v.22 no.2
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• pp.139-151
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• 1997

An ATM switching system may be designed so that communications between processors of its control part can be performed via its switching network rather than a separate inter-processor communications (IPC) network. In such a system, there should be interfaces to convent IPC traffic from message format to cell format and vice versa, that is, mechanisms to perform the SAR (Segmentation And Reassembly) sublayer functions. In this paper, we concern the cell reassembly mechanism among them, mainly focussed on buffer management schemes. We consider a few alternatives to implement cell reassembly function block, namely, separated buffering, reserved buffering and shared buffering in this paper. In case of separated and reserved buffering, we employ a continuous time Markov chain for the performance evaluation of cell reassembly mechanism, judicially defining the states of the mechanism. Performance measures such as measage loss probability, mean number of message queued in buffer and average reassembly delay are obtianed in closed forms. In case of shared buffering, we compare the alternatives for implementing cell reassembly function block using simulation because it is almost impossible to analyze the mechanism of shared buffering by analytical modeling. Some illustrations are given for the performance analysis of the alternatives to implement cell reassembly function block.

• Journal of Biosystems Engineering
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• v.32 no.5
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• pp.301-308
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• 2007

Sesame has usually been harvested manually in korea. The conventional sesame harvest procedures consists of cutting, binding, drying and pod shattering. The procedures of drying and shattering are repeated $2{\sim}3$ times. By manual works of this conventional shattering, it was found that some extent of pods were has always remained unopened. Therefore, this study was conducted to find a way to save the labor of sesame shattering by use of a drying device; a prototype of shattering machine was developed and tested the performance. The developed prototype consists of several parts: a continuous horizontal inlet using a chain conveyer, a shattering by a shocking agitator, a rotating cone for shattering of remaining closed pods, and a winnow. The shattering ratio measured by this prototype was 90.3%, 6.4% and 3.3% at the first, second and third shattering step, respectively. We found that in contrast to the conventional method which required at least 3 times operations for complete shattering, this shattering prototype with the condition of sufficient dried sesame pod offered more than 90% of shattering ratio in the first operation.

• Asian Journal of Atmospheric Environment
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• v.4 no.2
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• pp.63-71
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• 2010

The removal characteristics for aromatic and aliphatic VOCs by electron beam (EB) were discussed in terms of several removal variables such as initial VOC concentration, absorbed dose, background gas, moisture content, reactor material and inlet temperature. It was reviewed that only reactor material was an independent variable among the potential control factors concerned. It was also suggested that main mechanism by EB should be radical reaction for the VOC removal rather than that by primary electrons. It was discussed that the removal efficiency of benzene was lower than that of hexane due to a closed benzene ring. In the case of aromatic VOCs, it was observed that the decomposition of the VOCs with more functional groups attached on the benzene ring was much easier than those with less ones. As for aliphatic VOCs, it was also implied that the longer carbon chain was, the higher the removal efficiency became. An EB-catalyst hybrid system was discussed as an alternative way to remove VOCs more effectively than EB-only system due to much less by-products. This hybrid included supporting materials such as cordierite, Y-zeolite, and $\gamma$-alumina.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2006.05a
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• pp.295-296
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• 2006

We developed wire frame drive unit based on SMA for the 3D Shape display. Our basic concept is wire frame combination connected with a chain form which can create various shapes and it compared with pin array mechanism which is not able to display mushroom shape. It imitates antagonist mechanism of human musculoskeletal system. we create similar motion using repair-relaxation mechanism and locking mechanism by SMA. Therefore, in this paper, we propose SMA control solution for actuating repair-relaxation mechanism and locking mechanism. In our control system. we use optical sensor and quantitative angle between wire frames for closed loop control. And we supply amplified current for SMA by circuit composed of transistor and apply PWM signal to circuit for efficient control. So, wire frame drive unit enable diversity angle control based on sensor data. And then combination of wire frame drive units will create various objects.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.25 no.5
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• pp.354-361
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• 2016

Parallel robots are usually used for performing pick-and-place motion to increase productivity in high-speed environments. The present study proposes a high-speed parallel robot and a control approach to improve the tracking performance for the purpose of handling a solar cell. However, the target processes are not limited to the solar cell-handling field. Therefore, a delta-type parallel manipulator is designed, and a ball joint structure is specifically proposed to increase the allowed angle that would meet the required workspace. A control algorithm considering the synchronization between multiple joints in a closed-chain mechanism is also suggested to improve the tracking performance, where the tracking and synchronization errors are simultaneously considered. In addition, a prototype machine with the proposed ball joint is implemented. A satisfactory tracking performance is achieved by applying the proposed control algorithm, with a cycle time of 0.3 s for a 0.1 kg payload.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.50 no.1
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• pp.60-66
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• 2005

Pod shape of twenty soybean (Glycine max L. Merrill) genotypes was evaluated quantitatively by image analysis using elliptic Fourier descriptors and their principal components. The closed contour of each pod projection was extracted, and 80 elliptic Fourier coefficients were calculated for each contour. The Fourier coefficients were standardized so that they were invariant of size, rotation, shift, and chain code starting point. Then, the principal components on the standardized Fourier coefficients were evaluated. The cumulative contribution at the fifth principal component was higher than $95\%$, indicating that the first, second, third, fourth, and fifth principal components represented the aspect ratio of the pod, the location of the pod centroid, the sharpness of the two pod tips and the roundness of the base in the pod contour, respectively. Analysis of variance revealed significant genotypic differences in these principal components and seed number per pod. As the principal components for pod shape varied continuously, pod shape might be controlled by polygenes. It was concluded that principal component scores based on elliptic Fourier descriptors yield seemed to be useful in quantitative parameters not only for evaluating soybean pod shape in a soybean breeding program but also for describing pod shape for evaluating soybean germplasm.

• The Journal of Korean Academy of Orthopedic Manual Physical Therapy
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• v.7 no.2
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• pp.23-39
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• 2001

Dysfunction of the anterior and dorsal muscles of the trunk have been studied in relation to low back pain of many years. Many muscles of the trunk are capable of contributing to the stabilization and protection of the lumbar spine, recent evidence has suggested that transversus abdominis may be critically involved and has been the focus of rehabilitation. The delay in onset of contraction of trunk muscles associated with movement of the upper or lower limb in patients with low back pain indicates a significant deficit in the automatic motor command for control of disturbance to the spine. The function of transversus abdominis has been largely ignored in the evaluation of spinal stabilization and protection. The most essential stabilizing muscles for the lumbar column are the transversus abdominis and the multifidus. Sling exercise therapy(SET) concept consists of a system of diagnosis and treatment. The system of diagnosis involves testing the muscle's tolerance through progressive loading in open and close kinetic chains. The SET system contains elements such as relaxation, increasing the range of movement, traction, training the stabilizing musculature, sensorimotor exercises, training in open and close kinetic chains, dynamic training of the mobilizing musculature, cardiovasc+ular exercises, group exercise, personal exercise at home. Sensorimotor training is an essential element of the SET concept. The emphasis is on closed kinetic chain exercises on an unstable surface, thereby achieving optimum stimulation of the sensorimotor apparatus.

• International Journal of Advanced Culture Technology
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• v.3 no.2
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• pp.1-14
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• 2015

The purpose of this paper is to reveal two problems in the existing inventory systems in retail market, and to suggest a Two-Bin System under Automatic Ordering System considering only base-stock. Large retailers already have a sophisticated inventory system based on an automatic ordering principle. However, why does the out-of-stock (OOS) happen in large discount stores in spite of having a good inventory system? This paper suggests two systems after finding the root causes concerning the previous question. For evaluating the performance of each system, the random 200 data set in each sample group was generated from MINITAB 16 and obeyed the Poisson distribution. The existing inventory system in retail market cannot help generating OOS due to indwelling contradiction in itself. The reasons are the ordering deadline and the relationship between ordering quantity and base stock. This paper also demonstrates that these previous studies on inventory fall into the closed loop. Also the paper shows that the performance of the replenishment policy was better than traditional methods dealing with ordering quantity and base stock.

• Journal of the Optical Society of Korea
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• v.6 no.3
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• pp.121-127
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• 2002

The operating principal of a ring laser gyroscope depends on the phase difference for the counter-propagating waves within a closed path. The reflecting mirrors mounted on the monoblock form the traveling waves. The manufacturing accuracy of the monoblock influences the traveling path of ray, the sensitivity of laser resonator for misalignments, and diffraction losses. A 3 $\times$ 3 ray transfer matrix was derived for optical components with centering and squaring errors in a ring resonator. The matrix can be utilized to predict the optical ray paths on the basis of the manufacturing errors of the monoblock as well as the misalignment of mirrors. Then the distance and orientation (o. slope) at the arbitrary plane inside the resonator along the ideal optical path can be calculated from the chain multiplication of the ray transfer matrix for each optical component in one round trip. We also show that the counter-propagating rays In a ring resonator with errors does not coincide in each round trip, which results in gain difference between two beams, and how these errors can be adjusted through the alignment procedure. Finally this 3 $\times$ 3 ray matrix formalism can be used to calculate the beam size and its displacement from the optical axis and the deviation at the diaphragm.

• Korean Journal of Applied Biomechanics
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• v.28 no.4
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• pp.219-225
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• 2018

Objective: Epidemiological research shows that 47 to 73% of athletes suffer from recurrent ankle sprains. Joint mobilization techniques (JMT) implemented in correcting may be beneficial in the management of ankle injuries. The purpose of this study is to examine the immediate JM on ankle complex as clinical measures in individuals with chronic ankle instability (CAI) through intervention. Method: Thirteen subjects with CAI (8 males and 5 females) participated in this study. Each subject tried total four alignments (Navicular drop test: NDT, Standing rearfoot angle: SRA, Tibia torsion: TT, and dorsiflexion range of motion: DFROM). The participants were performed the 10 meter shuttle run after JMT for post-task. Finally, it was tried to compare between pre-post tasks after shuttle run. Results: SRA and DFROM after intervention showed significant differences. SRA (p=.026), and DFROM (p=.034). Conclusion: We concluded that the JMT has resulted in improvement in SRA, DFROM. Increased DFROM and varus shapes of foot would be closed kinetic chain, indicating that reduce the risk factors of ankle sprain. Future study needs to be conducted in order to measure the effects of prolonged intervention of JMT.