• Journal of Broadcast Engineering
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• v.13 no.6
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• pp.892-904
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• 2008

As a video encoding in resource constrained environments such as sensor networks has become an important issue, DVC(Distributed Video Coding) has been intensively investigated as a solution for light weighted video encoding problem. Known as one of the representative schemes of DVC, the Wyner-Ziv coding generates side information of current frame only at decoder, using correlation among frames, and reconstructs video through noise elimination on the side information using channel code. Accordingly, the better quality of side information brings less channel noise, thus attains better coding performance of the Wyner-Ziv coder. However, since it is hard for decoder to generate an accurate side information without any information of original frame, a method to successively improve side information using successively decoded original frame, based on decoding reliability, was previously developed. However, to improve side information from decoding results, not only an error rate of the decoding result as a reliability, but also the amount of reliable information from the decoding result is important. Therefore, we propose TDWZ(Transform-domain Wyner-Ziv coding) with successively improving side information based on decoding reliability considering not only an error rate but also the amount of reliable information of the decoding results. Our experiment shows the proposed method gains average PSNR up to 1.7 dB over the previous TDWZ, that is without successive side information improvement.

• Journal of the Korea Society for Simulation
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• v.23 no.4
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• pp.51-64
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• 2014

Small and medium Enterprises (SMEs), which have a manufacturing method of small quantity batch production produce goods using a general-purpose equipment and attached auxiliary tools. Many previous studies have focused on finding the effective resource allocations for improving the firms' productivity. It is very important for SMEs to keep costs low in assigning jobs to each resource, because they should meet the future uncertain demand of consumers under the limited budget. Using the concept of salvage cost, this paper proposes how to effectively allocate the tasks to main resources in the production process. The salvage cost is defined that purchasing cost minus decrease in value by workload, the method considering this is expected to reduce total purchasing costs during business period. To validate the effect of the proposed method, we proceed the real case study targeting on S company, PCB manufacturer to compare purchase amounts and its costs between the allocation proposed based salvage cost and current allocation method of current S company. As a results, In short-term (3 year) business period, salvage allocation have remarkable superior outcome to existing method, but gradually have cancelled out the effects in long-term (8 year) plans. Unlike the cycle allocation method, there exists the idle-equipments in allocation based salvage value. we additionally analyze the profits with respect to rental strategy of them during business period.

• Journal of radiological science and technology
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• v.33 no.2
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• pp.93-96
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• 2010

This study evaluates usefulness of the developed assistant device by taking projection of patellofemoral joint in emergency patients who were doubt posterior cruciate ligament injury in knee joint. The subjects of experiment were patients who visited Eul-Ji University Hospital due to knee injury from January 2006 to December 2006. Seventeen patients, who took the Knee post stress view, Knee merchant view, Knee Seo's view to use assistant device and Knee MRI. To make assistant device of $170{\times}50{\times}70\;cm$, we evaluated its usefulness by measuring posterior dislocation of tibia. Seo's view is more accurate to make judgment of posterior cruciate ligament injury than original knee post stress view. Interval difference of posterior dislocation of original knee post stress view is $6.17{\pm}3.04$ and Seo's view is $8.74{\pm}4.47$. The results show injury of patellofemoral joint, vertical fracture of patella and posterior cruciate ligament injury by taking a projection using Seo's view. Therefore, it is useful to take projection earlier than talometer and MRI in emergency patients who were doubt posterior cruciate ligament injury in knee joint.

• Journal of the Institute of Electronics Engineers of Korea SC
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• v.42 no.2 s.302
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• pp.49-58
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• 2005

A new soft switching three-phase PWM rectifier with simple circuit configuration and high efficiency has been developed. The proposed circuit is a kind of the auxiliary resonant commutated Pole(ARCP)converter The conventional ARCP converter requires three-auxiliary reactors and six-auxiliary switches for the soft switching auxiliary circuit and for these switching elements, a gate drive circuit and a control circuit are required, resulting in high part as a disadvantage. In the main circuit proposed in this paper, the auxiliary soft switching circuit is composed of two-auxiliary reactors, two-auxiliary switches and several diodes. In addition, common use of the PWM control circuit for two-switches will make the control circuit of the auxiliary switches simple. By means of function of the soft switching auxiliary circuit, the main switching element performs zero voltage switching operation and the auxiliary switches perform the zero current switching. In this paper, the circuit configuration and the operational analysis of the proposed circuit are described at first and then, experimental results will be reported. By using a prototype with 5[kW] capacity, the conversion efficiency of maximum $98.8[\%]$ and the power factor of $99[\%]$ or higher were obtained.

• Food Engineering Progress
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• v.15 no.2
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• pp.175-181
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• 2011

By using supercritical carbon dioxide fluid, an attempt was made to extract surface-active substances from defatted rice bran. Extraction was carried out according to D-optimal design and results were analyzed by response surface methodology to establish optimum condition. It was found that pressure, temperature and co-solvent (ethanol) influenced in a different extent on the extraction efficiency (i.e., yield and interfacial tension) of surface-active substances. Among them, co-solvent was found to be a major influencing factor, where maximum yield (2.62%) was observed at the highest content (250 g). In addition, it also affected most on the interfacial tension at the oil-water interface but in this case the lowest interfacial tension value (9.51 mN/m) was found when added lowest (50 g). In conclusion, it was estimated that the optimum extraction condition was to be pressure 350bar, temperature $62^{\circ}C$ and co-solvent content 50 g in this study, where extraction yield was 0.69% and interfacial tension to be 10.1 mN/m.

• Journal of the Korean Society of Earth Science Education
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• v.12 no.1
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• pp.109-118
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• 2019

The purpose of this study was to investigate the effects of experience as a science experiment assistant teacher on the science instruction anxiety and the science teaching efficacy beliefs of elementary pre-service teachers in a small scale school. For this study, 21 elementary pre-service teachers were selected and then they worked as science experiment assistant teachers in small scale schools for about 10 months. They were tested the science instruction anxiety and the science teaching efficacy beliefs in before and after. After analyzing the tests results, some pre-service teachers were interviewed. The results of this study are as follows. The experiences as science experiment assistant teachers positively influenced on reducing the science instruction anxiety to elementary pre-service teachers. The experiences also had positive effects on reducing both state anxiety and trait anxiety, which are the sub-factors of science instruction anxiety. In addition, the science teaching efficacy beliefs and its sub-factor, the self-efficacy in science teaching, had positive impacts, but the experiences did not have a positive impact on the outcome expectancy. The effects of the experience as a science experiment assistant teacher were different according to the personal experiences and cognitions of pre-service teachers.

• Convergence Security Journal
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• v.21 no.3
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• pp.75-80
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• 2021

This study provided personnel and recruitment information related to job offer and job hunting, and proposed a non-face-to-face platform that can facilitate matching of one-time services as well as periodic services. The existing recruitment and job search method for personal assistant of the disabled is a one-way matching method in which a person in charge of the service providing centers assigns an activity assistant belonging to the institution when a consumer requests an personal assistant service, so the choice of job seekers is very weak. The job matching platform of the activity assistant for the disabled can be logged in separately by dividing users and separating them into the interface of the disabled or the disabled family members (job seekers) and activity assistants for the disabled (job seekers). Search for job offer and job seekers that meet their respective conditions, and real-time bidirectional decision-making through the chat function, and when the activity assistance service is completed, recruiters and job seekers can write service reviews and evaluations from their own point of view. The real-time interactive decision-making matching platform will also help minimize blind spots where it is difficult to provide services when short-term or one-time assistance is needed.

• Tuberculosis and Respiratory Diseases
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• v.45 no.2
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• pp.380-387
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• 1998

Background: Minimal pressure support(PSmin) is a level of pressure support which offset the imposed work of breathing(WOBimp) developed by endotracheal tube and ventilator circuits in pressure support ventilation While the lower applied level of pressure support compared to PSmin could induce respiratory muscle fatigue, the higher level than PSmin could keep respiratory muscle rest resulting in prolongation of weaning period during weaning from mechanical ventilation PSmin has been usually applied in the level of 5~10 cm$H_2O$, but the accurate level of PSmin is difficult to be determinated in individual cases. PSmin is known to be calculated by using the equation of "PSmin = peak inspiratory flow rate during spontaneus ventilation$\times$total ventilatory system resistance", but correlation of calculated PSmin and measured PSmin has not been known. The objects of this study were firstly to assess whether customarily applied pressure support level of 5~10 cm$H_2O$ would be appropriate to offset the imposed work of breathing among the patients under weaning process, and secondly to estimate the correlation between the measured PSmin and calculated PSmin. Method : 1) Measurement of PSmin : Intratracheal pressure changes were measured through Hi-Lo jet tracheal tube (8mm in diameter, Mallinckroft, USA) by using pulmonary monitor(CP-100 pulmonary monitor, Bicore, USA), and then pressure support level of mechanical ventilator were increased until WOBimp was reached to 0.01 J/L or less. Measured PSmin was defined as the lowest pressure to make WOBimp 0.01 J/L or less. 2) Calculation of PSmin : Peak airway pressure(Ppeak), plateau airway pressure(Pplat) and mean inspiratory flow rate of the subjects were measured on volume control mode of mechanical ventilation after sedation. Spontaneous peak inspiratory flow rates were measured on CPAP mode(O cm$H_2O$). Thereafter PSmin was calculated by using the equation "PSmin = peak inspiratory flow rate$\times$R, R = (Ppeak-Pplat)/mean inspiratory flow rate during volume control mode on mechanical ventilation". Results: Sixteen patients who were considered as the candidate for weaning from mechanical ventilation were included in the study. Mean age was 64(${\pm}14$) years, and the mean of total ventilation times was 9(${\pm}4$) days. All patients except one were males. The measured PSmin of the subjects ranged 4.0~12.5cm$H_2O$ in 14 patients. The mean level of PSmin was 7.6(${\pm}2.5\;cmH_2O$) in measured PSmin, 8.6 (${\pm}3.25\;cmH_2O$) in calculated PSmin Correlation between the measured PSmin and the calculated PSmin is significantly high(n=9, r=0.88, p=0.002). The calculated PSmin show a tendancy to be higher than the corresponding measured PSmin in 8 out of 9 subjects(p=0.09). The ratio of measured PSmin/calculated PSmin was 0.81(${\pm}0.05$). Conclusion: Minimal pressure support levels were different in individual cases in the range from 4 to 12.5 cm$H_2O$. Because the equation-driven calculated PSmin showed a good correlation with measured PSmin, the application of equation-driven PSmin would be then appropriate compared with conventional application of 5~10 cm$H_2O$ in patients under difficult weaning process with pressure support ventilation.

• Journal of Chest Surgery
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• v.35 no.5
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• pp.329-335
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• 2002

Background: The surgical technique for biventricular assist device(BVAD) implantation has mainly consisted of cannulation procedures. A median sternotomy has been the technique of choice as it gives a surgeon an excellent exposure of the heart. However, considering that most patients require a future sternotomy or already have a previous sternotomy, sternotomy-related complication remains a major concern in BVAD implantation. Based on this consideration as well as the clinical experiences of conventional heart surgery, the authors have hypothesized that the cardiac chambers for BVAD cannulation can be approached from the right side of the heart. The purpose of this studs to develop a novel surgical technique of right thoracotomy for BVAD implantation in an animals study. Material and Method: For last two years, 16 (11 calves, 3 canines, and 2 sheep) out of 30 experimental animals with AnyHeart implantation underwent a right thoracotomy. The device was used as an implantable BVAD in 14 animals, a wearable BVAD in 1, and an implantable LVAD in 1. The chest cavity was entered through the 4th intercostal space or the 5th periosteal bed. As for the BVAD use, a right inflow cannula was inserted into the right atrial free wall and a right outflow cannula was grafted onto the main pulmonary artery. A left inflow cannula was inserted into the interatrial groove and a left outflow cannula was grafted on the innominate artery of the ascending aorta. The connecting tubes were brought out through the thoracotomy wound and connected to the pump located in the subcutaneous pocket at the right flank. Result: Except for the 5 animals for a lilting test or during the early learning curve, all recovered smoothly from the procedures. The inflow drainage allowed the pump output 6.5 L/min at the maximum with 3-3.5 L/min in an average. Of the survivors, there noted no procedure-related mortality or morbidity. Necropsy findings demonstrated the well-positioned cannula tips in the each cardiac chamber

• Journal of Chest Surgery
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• v.42 no.5
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• pp.604-609
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• 2009

Background: Recently, percutaneous cardiopulmonary support (PCPS) has been widely used to rescue patients in cardiogenic shock or cardiac arrest. However, patients with cardiopulmonary bypass (CPB) weaning failure during open heart surgery still have very poor outcomes after PCPS. We investigated clinical results and prognostic factors for patients who underwent PCPS during open heart surgery. Material and Method: From January 2005 to December 2008, 10 patients with CPB weaning failure during open heart surgery underwent PCPS using the CAPIOX emergency bypass system ($EBS^{(R)}$, Terumo Inc, Tokyo, Japan). We retrospectively reviewed the medical records of those 10 patients. Result: The average age of the patients was $60.2{\pm}16.5$ years (range, $19{\sim}77$ years). The mean supporting time was $48.7{\pm}64.7$ hours (range, $4{\sim}210$ hours). Of the 10 patients, 6(60%) were successfully weaned from the PCPS While 5 (50%) were able to be discharged from the hospital. Complications were noted in 5 patients (50%). In univariate analysis, long aortic cross clamp time during surgery, mediastinal bleeding during PCPS and high level of Troponin-I before PCPS were significant risk factors. All of the discharged patients are still surviving $34{\pm}8.6$ months (range, $23{\sim}48$ months) post-operatively. Conclusion: The use of PCPS for CPB weaning failure during open heart surgery can improve the prognosis. More experience and additional clinical studies are necessary to improve survival and decrease complications.