• Transactions of the Korean Society of Automotive Engineers
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• v.7 no.8
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• pp.132-142
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• 1999

In this paper, a new formula for primary and secondary thrust of metal belt CVT is proposed considering variation of band tension, block compression and active arc for each of the primary and secondary pulleys. For the secondary thrust, effective friction coefficient is introduced considering the effect of flange deflection. Nondimensional primary and secondary thrust of the metal belt CVT by the new formula agree well with the experimental results except for low torque range, $0\;<\;{\lambda}\;<\;0.2$ at speed ration i = 1.0. The new formula can be used in design of the primary and secondary thrusts control system for the metal belt CVT.

• KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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• v.7 no.1
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• pp.21-24
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• 2001

This study was carried out to analyze the effects of packaging units and loading types in agricultural products(apple, pear, and sweet persimmon) palletization. In apple and pear packaging, an optimum loading type was pin wheel loading, and load effective corrugated box dimension was $330{\times}220{\times}170mmm(L{\times}W{\times}H)$ in 5 and 10kg packaging units, but in case of pear box was 10mm higher than apple box. However, in sweet persimmon packaging, block loading was available, and box dimension of $365{\times}275{\times}180mm(L{\times}W{\times}H)$ was the most effective to palletize.

• Macromolecular Research
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• v.15 no.3
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• pp.211-215
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• 2007

Hybrid thin film nanostructures composed of metal nanoparticles (NPs) and self-assembled polymer films with different spatial distributions of NPs were analyzed by optical waveguide spectroscopy (OWS). Specifically, the dielectric constants were calculated using effective medium theory for the incorporation of 1 vol% Au NP into the block copolymer (BCP) films having a cylindrical nanodomain morphology. Three cases were considered: uniform distribution of NPs in the film; selective distribution of NPs only in the cylindrical domains; and segregation of NPs to the center of the cylindrical domains. The optical waveguide spectra derived from the calculated dielectric constants demonstrate the feasibility of experimentally distinguishing the composite nanostructures with different inner morphologies in the hybrid metal NP-BCP nanostructures, by the measurement of the dielectric constants using OWS.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.22 no.1
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• pp.33-39
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• 2018

An additive noise reduction algorithm for a mass spectrum analyzer is proposed. From the measured ion signal, we first used an estimated threshold from the mode of the measured signal to eliminate background noises with the white Gaussian characteristics. Also, a signal block corresponding to each mass index is constructed to perform a second order curve fitting and a linear approximation to signal block. In this process, the effective signal block composed of only the ion signal can be reconstructed by removing the impulsive noises and the sample signals which are insufficient to be viewed as normal ion signals. By performing curve fitting on the effective signal block, the noise-free mass spectrum can be obtained. To evaluate the performance of the proposed method, a simulation was performed using the signals acquired from the development equipment. Simulation results show the validity of the threshold setting from the mode and the superiority of the proposed curve fitting and linear approximation based noise canceling algorithm.

• KIPS Transactions on Software and Data Engineering
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• v.10 no.4
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• pp.115-124
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• 2021

Since function block diagram (FBD) programs are widely used to implement safety-critical systems, effective testing for FBD programs has become important. Mutation testing, a fault-based testing, is highly effective in fault detection but computationally expensive. To support testers for FBD programs, we propose an automated mutant generator for FBD programs. We designed the MuGenFBD tool with the cost and equivalent mutant issues in consideration. We conducted experiments on real industrial examples to present the performance of MuGenFBD. The results show that MuGenFBD can generate mutants for FBD programs automatically with low probability of equivalent mutants and low cost. This tool can effectively support mutation analysis and mutation-adequate test generation for FBD programs.

• Journal of the Korean Institute of Landscape Architecture
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• v.34 no.3 s.116
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• pp.12-22
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• 2006

The purpose of this study is to evaluate visual preferences of the methods for river embankment based on seasonal changes and to reveal the relationship between visual preference and effective factors, which are the physical and esthetic elements inside the river. For this research seven river embankment methods including concrete block, concrete wall, gabion, and vegetated concrete block were selected in Dongchon of Gwangyang. Twenty-eight pictures by the four pictures of each embankment method based on seasonal changes, the winter and summer of the first and second years after construction were used for a photo-questionnaire by 49 participants. In the analysis of the relationship between visual preference and effective factors, the independent variables included eight factors: form of the material, harmony with the surroundings, the cleanness of river floor, the green area of embankment methods, the water area in river floor, the stone and sand area in river floor, the planting area in river floor, and the area of embankment itself. The result of this study are as follows. First, visual preference in summer was higher than in winter, and the summer landscape of the second you scored the highest value for visual preference. Second, similarly to the way the vegetated concrete block produced a green effect, cobblestone and gabion embankments made of natural materials scored higher than others, whereas the concrete retaining wall scored the lowest of all methods because of it's artificiality. Third, the seven independent variables, except form of the material, are proved statistically significant at the 5% level. The water area in river floor, harmony with the surroundings, the planting area in river floor, and the cleanness of the river floor were revealed as more effective factors influencing visual preference. The research results suggest that the riverscape has to be controlled in terms of seasonal change and embankment methods. Natural materials and green effects in embankment methods are more important for increasing landscape preference, and the landscape factors inside a river should also be considered important variables. It is recommended that advanced study on other factors affecting visual preference of the riverscape be carried out to support this research.

• Journal of KIISE
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• v.44 no.10
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• pp.1034-1044
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• 2017

Although traversal strategies are important for the performance of model checking, many studies have ignored the impact of traversal strategies in model checking with a block-encoded abstract reachability graph. Studies have considered traversal strategies only for an abstract reachability graph without block-encoding. Block encoding plays a crucial role in the model checking performance. This paper therefore describes Dual-traversal strategy, a simple and novel technique to control traversal strategies in a block-encoded abstract reachability graph. This method uses two traversal strategies for a model checking, one for effective block-encoding, and the other for traversal in an encoded abstract reachability graph. Dual-traversal strategy is very simple and can be implemented without overhead compared to the existing single-traversal strategy. We implemented the Dual-traversal strategy in an open source model checking tool and compare the performances of different traversal strategies. The results show that the model checking performance varies from the traversal strategies for the encoded abstract reachability graph.

• Advances in pediatric surgery
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• v.20 no.1
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• pp.7-11
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• 2014

The present study compared the postoperative analgesic effects of ilioinguinal and iliohypogastric nerve block with infiltration of local anesthetics (bupivacaine) into the wound in children after inguinal hernia repair. Ninety children below 7 years old who were scheduled elective inguinal hernia repair were randomly allocated into one of three groups. The patients in nerve block (NB) group, ilioinguinal and iliohypogastric nerve block was done with 0.5 mL/kg of 0.25% bupivacaine. The patients in infiltration of local anesthetics (LI) group, 0.5 mL/kg of 0.25% bupivacaine was infiltrated into the wound after surgery. The patients in control group were allocated as a Control group. Postoperative pain was assessed at 1, 3, 5, and 24 hours after operation with FLACC scale and additional analgesic consumption were counted. The three groups were not significantly different in age, sex, body weight, and duration of operation. Pain scores at 1 hour and 3 hours after operation were significantly higher in Control group than in NB group and LI group (p<0.01), whereas there were no difference between NB group and LI group. The rescue analgesics administration was significantly higher in Control group (n=11) than in NB group (n=6) and LI group (n=7) (p<0.05). There were 2 cases of transient femoral nerve palsy in NB group. Both of ilioinguinal and iliohypogastric nerve block and infiltration of local anesthetics into the wound provided effective postoperative analgesia in early postoperative period following inguinal hernia repair in children. But no difference between the two methods. Technically, infiltration of local anesthetics into the wound was easier and safer than ilioinguinal and iliohypogastric nerve block.

• The Korean Journal of Pain
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• v.20 no.1
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• pp.54-59
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• 2007

Background: Selective transforaminal epidural block (STEB) has showen effectiveness as a diagnostic and therapeutic option for the management of patients with low back pain or sciatica. This study was carried out in order to determine the short-term effects and prognostic factors associated with STEB in patients with low back pain or sciatica. Methods: Ninety-seven patients were selectedfor participation in this study. Their diagnosis were based werewason the clinical symptoms and MRI findings. We performed STEB under fluoroscopic guidance and injected 3 ml of radio opaque dye in order to confirm the technical success of the procedure. We then injected 20 mg of triamcinolone mixed into 3 ml of 0.5% mepivacaine. One month later, we classified the patient outcomes as excellent, good, moderate or poor, according to the degree of reduction in VAS score from baseline. The independent variables assessed included symptom duration, block level, number of blocks, primary diagnosis, prior caudal block, anterior epidural space filling of dye, medication history, demographic data, radiating pain, back surgery and spondylolisthesis. Results: At a mean follow-up period of 1 month after STEB, excellent results were noted in the patients diagnosed with herniated lumbar disc (70%), non-specific spondylosis (54%), spinal stenosis (44%), and failed back syndrome (28%). The patients with epidural adhesion and combined spondylolisthesis were associated with poorer outcomes. Combined caudal block, symptom duration and the extent of epidural spread of the drug were not related to the effectiveness of the treatment. Conclusions: Selective transforaminal epidural block is effective in treating patients with radiculopathy, such as herniated lumbar disc, but it isrelatively ineffective in treating patients with structural deformities, such as failed back syndrome and spondylolisthesis.

• Journal of the Architectural Institute of Korea Planning & Design
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• v.35 no.6
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• pp.27-37
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• 2019

This study focused on the possibility of reducing the cooling load through the change of micro climate in the outdoor space during summer season. This study proposes an efficient planning model by comparing the effects of urban heat island mitigation through wind path planning, outdoor space vegetation, and exterior material change by using the basic model of the street-oriented block housing proposed in the previous research by the same author. As a result, the most effective wind path planning strategy in the street-oriented block housing was the change of the air flow through the mass height adjustment. When the tall building masses were staggered and arranged in a balanced manner, the overall wind environment could be improved. The greater the height difference between low and high masses, the better the air flow was shown. It was also important to arrange the building masses so that the inlet of the main wind was open and to allow the external space to connect to the adjacent block to create a continuous flow. The change of outdoor space vegetation and flooring, and the formation of wind paths through the opening of lower part also showed the effect of heat island reduction. In addition, the change of PMV in summer was the biggest influence of shadow by tall building mass. Attention should be paid to the fact that high-albedo exterior materials are adversely affected by multiple reflections in dense street-oriented block housing. The use of albedo of the exterior material showed that it is necessary to pay attention to apply in the high density block housing. This is attributed to the rise of the temperature due to the absorption of energy into the low-albedo flooring, where the high-albedo exterior causes multiple reflections.