• Korean Journal of Radiology
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• v.22 no.4
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• pp.604-611
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• 2021

Objective: The aim of this pilot study was to investigate the potential of early-phase single-photon emission computed tomography (SPECT)/computed tomography (CT) using technetium-99m methyl diphosphonate (^99mTc-MDP) for diagnosing osteomyelitis (OM). Materials and Methods: Twenty-one patients with suspected OM were enrolled retrospectively. Three-phase bone scan (TPBS), early-phase SPECT/CT (immediately after blood pool planar imaging), and delayed-phase SPECT/CT (immediately after delayed planar imaging) were performed. The final diagnoses were established through surgery or clinical follow-up for over 6 months. We compared three diagnostic criteria based on (I) TPBS alone, (II) combined TPBS and delayed-phase SPECT/CT, and (III) early-phase SPECT/CT alone. Results: OM was diagnosed in 11 of 21 patients (nine surgically and two clinically). Of the 11 OM patients, criterion-I, criterion-II, and criterion-III were positive in six, seven, and 10 patients, respectively. Of the 10 non-OM patients, criterion-I, criterion-II, and criterion-III were negative in five, five, and seven patients, respectively. The sensitivity/specificity/accuracy of criterion-I, criterion-II, and criterion-III for diagnosing OM were 54.5%/50.0%/55.0%, 63.6%/50.0%/57.1%, and 90.9%/70.0%/87.5%, respectively. Conclusion: This pilot study demonstrated the potential of using the early-phase SPECT/CT to diagnose OM. Based on the results, prospective studies with a larger sample size should be conducted to confirm the efficacy of early-phase SPECT/CT.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.12 no.3
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• pp.414-419
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• 2008

The six-port correlator is comprised of a power divider and three hybrid couplers. In this paper, the six-port phase correlator using three-arm branch $90^{\circ}$ hybrid coupler were designed with the center frequency of 11.85 GHz. The performances for the six-port phase correlator was analyzed by using ADS2003A tool. Three-arm six-port phase correlator provides more wide dynamic frequency range than that of six-port using the conventional hybrid coupler in range of circa five times, which is range of 10.8 to 12.3GHz (1.5 GHz). The phase errors among the output ports of the six-port phase correlator are below $5^{\circ}$. The six-port Phase correlator was fabricated to evaluate the Performance of the proposed six-port phase correlator. The measured performance of the six-port phase correlator shows the good accordance with the simulation data.

• Journal of Power Electronics
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• v.16 no.6
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• pp.2231-2242
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• 2016

A simplified model predictive control method is presented in this paper. This method is based on a future reference voltage vector for a three-phase four-leg voltage source inverter (VSI). Compared with the three-leg VSIs, the four-leg VSI increases the possible switching states from 8 to 16 owing to a fourth leg. Among the possible states, this should be considered in the model predictive control method for selecting an optimal state. The increased number of candidate switching states and the corresponding voltage vectors increase the calculation burden. The proposed technique can preselect 5 among the 16 possible voltage vectors produced by the three-phase four-leg voltage source inverters, based on the position of the future reference voltage vector. The discrete-time model of the future reference voltage vector is built to predict the future movement of the load currents, and its position is used to choose five preselected vectors at every sampling period. As a result, the proposed method can reduce calculation load by decreasing the candidate voltage vectors used in the cost function for the four-leg VSIs, while exhibiting the same performance as the conventional method. The effectiveness of the proposed method is demonstrated with simulation and experiment results.

• Journal of Power Electronics
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• v.17 no.3
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• pp.641-652
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• 2017

This paper proposes a cost-effective topology to drive a three-phase open-end load based on a five-leg indirect matrix converter (IMC) and a space vector modulation (SVM) method. By sharing an inverter leg with two load terminals, the proposed topology can reduce the number of power switches when compared to topologies based on a direct matrix converter or a six-leg IMC. The new SVM method uses only the active vectors that do not produce common-mode voltage (CMV), which results in zero CMV across the load phase and significantly reduces the peak value of the CMV at the load terminal. Furthermore, the proposed drive system can increase the voltage transfer ratio up to 1.5 and provide a superior performance in terms of an output line-to-line voltage with a three-level pulse-width modulation waveform. Simulation and experimental results are given to verify the effectiveness of the proposed topology and the new SVM method.

• Korean Journal of Oriental Medicine
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• v.15 no.2
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• pp.33-37
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• 2009

Objectives : The authors performed this study to further understand Saam acupuncture method in an aspect of formation process. Methods : We were finding Saam's idea in a preface of the book. And we analyzed Saam acupuncture patterns to understand their formation. Results & Conclusion : We assume that Saam acupuncture patterns has formed over time. We were able to split their patters into three phases. That is Primitive-phase, Basic-phase and Practical-phase. We think they are traces of Formation Process. In the first, Saam found DongHaeng-acupoints that have in common Five Element between the five viscera and acupoint. And then, he compounded other meridian's DongHeng-acupoints to control self meridian. Finally acupoints of self meridian were added.

• Journal of Power Electronics
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• v.14 no.1
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• pp.115-124
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• 2014

This paper presents the implementation of two-arm modulation (TAM) technique for the independent control of a two-induction motor drive fed by a five-leg inverter (FLI). A carrier-based space vector pulse width modulation technique for TAM is proposed to generate switching signals for FLI. Two independent three-phase space vector modulators are utilized to control two motors. The motor drive system applies two separate indirect field-oriented control methods. The stationary voltage outputs from the vector control are synthesized in the three-phase space vector modulator to generate switching signals for FLI. The performance of the independent control of the motors and the voltage utilization factor are likewise analyzed. Simulation and experimental results verify the effectiveness of the proposed method for the independent control of the two-motor drive system. The proposed technique is successfully validated by dSPACE DS1103 experimental work.

• Journal of the Korean Society for Railway
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• v.20 no.1
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• pp.43-54
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• 2017

This paper analyzes the performance of two three-leg inverters and a five-leg inverter and proposes the optimal operation conditions in applying the five-leg inverter for the train propulsion system. The five-leg inverter offers a saving of two switches compared with the standard two three-leg inverters and it is possible to control two three-phase motors independently by using a control board. All of these features lead to a potential reduction in capital cost and miniaturization of system. In this paper, first, the analysis of the existing motor control method and PWM method for two-traction motor drive of urban railway is implemented. Next, the operation principle and performance of five-leg inverter is introduced. Through the analysis, when it applies the same motor control method and the same PWM method for three-leg inverter and five-leg inverter, the characteristic of motor's speed and torque is compared.

• Journal of Electrical Engineering and Technology
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• v.8 no.2
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• pp.295-303
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• 2013

This paper reports an investigation of pulse width modulation (PWM) techniques for two-phase brushless DC (BLDC) motors fed by a two-phase eight-switch inverter in a fan application. The three-phase BLDC motor is widely applied in industry; however, a lower-cost two-phase BLDC motor and drive circuit has been greatly in demand in recent years. In this paper, we introduce a mathematical model of the two-phase BLDC motor with sinusoidal back electromotive forces (EMFs) based on traditional three-phase BLDC motors. To simplify the drive algorithm and speed up its application, we analyze the principle of block commutation for a two-phase BLDC motor drive in the 180-electrical-degree conduction mode, and we further propose five PWM schemes to improve the commutation performance of the two-phase BLDC drive. The effectiveness of the proposed PWM methods is verified through experiments.

• Asian-Australasian Journal of Animal Sciences
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• v.14 no.10
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• pp.1419-1424
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• 2001

Previous research in our laboratory has demonstrated the importance of lactose in phase I and II pig starter diets. Two experiments were conducted to evaluate the use of a carbohydrate by-product (food by-products) as a replacement for lactose. In Exp. I, 120 weaned pigs ($14{\pm}2d$ and 5.65kg) were allotted in a randomized complete block design (RCBD) to 10 replications with four pigs per pen. This experiment evaluated three carbohydrate sources (lactose, carbohydrate by-product, and 50-50 blend of the carbohydrate by-product and lactose). The carbohydrate sources were added at 26% in the phase I diets and 15% in the phase II diets. Phase I diets contained 7.5% spray dried plasma protein (SDP). The phase I diets were fed from d 0 to 14 and the phase II diets from d 15 to 28. There were no significant differences between carbohydrate sources on pig performance in phase I. However, during phase II pigs fed the diet with lactose had an improved gain/feed ratio (G/F) (p=0.06) compared to pigs fed the carbohydrate by-product. For the entire 28 d trial ADG, ADFI and G/F were similar for the 50-50 blend and those fed lactose. Total replacement of lactose with the carbohydrate byproduct resulted in a reduced G/F (p=0.09). Exp. 2 used 100 weaned pigs ($17{\pm}2d$ and 4.75kg) with five replications with five pigs per pen. This experiment evaluated four carbohydrate treatments (lactose, carbohydrate by-products, 50-50 blend, and corn). All phase I diets contained 3.5% SDP with the carbohydrate sources included at 15%, and were fed d 0 to 14. The phase II diets contained 7.5% of the carbohydrate sources and were fed d 15 to 27. A common phase III diet was fed d 28 to 42. During all phases pigs fed com tended to have a lower ADG than pigs fed the other carbohydrate sources with the 50-50 blend resulting in the highest ADG. The results of both experiments suggest that this carbohydrate by-product can replace at least 50% of the lactose in phase I and phase II pig starter diets.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.3
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• pp.1225-1233
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• 2015

This study aims to clarify the psychosocial reactions of female patients with gynecological cancer undergoing chemotherapy and in the process of suffering from alopecia and to examine their nursing support. The target group comprised female patients who had received two or more cycles of chemotherapy, were suffering from alopecia, and were aged 30-65. Data were collected from semi-structured interviews, conducted from the time the patients were informed by their doctors that they might experience alopecia due to chemotherapy to the time they actually experienced alopecia and until they were able to accept the change. Inductive qualitative analysis was employed to close in on the subjective experiences of the cancer patients. The results showed the existence of six phases in the psychosocial reactions in the process of alopecia: phase one was the reaction after the doctor's explanation; phase two was the reaction when the hair starts to fall out; phase three was the reaction when the hair starts to intensely fall out; phase four was the reaction when the hair has completely fallen out; phase five was the reaction to behavior for coping with alopecia; and phase six was the reaction to change in interpersonal human relationships. The results also made it clear that there are five types of reaction patterns as follows: 1) treatment priority interpersonal relationship maintenance type; 2) alopecia agitated interpersonal relationship maintenance type; 3) alopecia agitated interpersonal relationship reduction type; 4) alopecia denial interpersonal relationship reduction type; and 5) alopecia denial treatment interruption type. It is important to find out which of the five types the patients belong to early during treatment and provide support so that nursing intervention that suits each individual can be practiced. The purpose of this study is to make clear the process in which patients receiving chemotherapy come to accept alopecia and to examine evidence-based nursing care on patients with strong mental distress from alopecia.