• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.3
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• pp.93-102
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• 2016

This study examined effects of the communication accompanied with music therapy on the anxiety of patients during a MRI examination. In the experiment group consisting of thirty patients and the control group consisting of thirty patients, the experiment was performed from February 1st 2014 to March 31st 2014 in hospital C located in Daegu Korea. The research design was a non-equivalent control group quasi-experimental study. The results showed that the anxiety score (VAS score) on communication with music therapy of the experimental group was significantly lower (p=.001), than that of the control group. Among the vital signs, the blood pressure was similar in both groups. On the other hand, the pulse rate of the experiment group was significantly lower (p=.001). Four categories of the physical discomfort (perspiration, facial change, change in physical posture, and change in vocal sound) did not show any statistically significant difference between the control and experiment group. Among the mental discomforts, dizziness did not have a significant difference between the experiment group and the control group, but the experimental group had significantly low fear (p=.001) and anxiety (p=.001). From the above results, communication accompanying music therapy proves is an effective alternative examination method that reduces the anxiety of patients.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.6
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• pp.1-7
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• 2017

The atomization of a liquid into multiple droplets has many important industrial applications, including the atomization of fuels in combustion processes and coating of surfaces and particles. Ultrasonic atomizing nozzle has a transducer that receives electrical input in the form of a high frequency signal from a power generator and converts that into mechanical energy at the same frequency. Liquid is atomized into a fine mist spray using high frequency sound vibrations. In coating applications, the unpressurized, low-velocity spray reduces the amount of overspray significantly because the droplets tend to settle on the substrate, rather than bouncing off it. The spray can be controlled and shaped precisely by entraining the slow-moving spray in an ancillary air stream using specialized types of spray-shaping equipment. The desired patterns of spray can be obtained using an air stream. To simulate the water mist behavior of an ultrasonic atomizing nozzle using an air stream, the Lagrangian dispersed phase model was employed using the commercial code FLUENT. The effects of the nozzle contraction shape, water droplet size and the pneumatic pressure drop on the spray characteristics were investigated to obtain the optimal condition for coating applications.

• Journal of Korean Society of Environmental Engineers
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• v.31 no.8
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• pp.635-640
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• 2009

After 1960s, in accordance with getting bigger in changing range of annual rain precipitation, those dams were built in order to prevent any drought and flood through the regulation of flux. In case of such dam, when it reaches to some definite pondage, for its regulation of water volume, numerous volume of water in the reservoir should be discharged by opening the floodgate, at this time a severe damage can be occurred to those lives and properties of the residents and tourists at the river or riverside. Accordingly, despite the sounding alarm broadcasting for prevention and notice such damage could be clearly travelled to those people without influence by the discharging noise or other neighboring environmental factor, since it was only empirically installed without any peculiar research until now, the alarm broadcasting could not effectively travel, and the travelling distance also could not known correctly. On such point of view, this Study has ever grasped the characteristics by frequencies and its sound pressure level about the discharge noise and the alarm broadcasting of Daechung Dam, one of multipurpose dams through the measurement and analysis by distances, and based on this, also has ever presupposed the proper location of additional alarm broadcasting spot using a simulation program named Cadna-A.

• International Journal of Highway Engineering
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• v.17 no.6
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• pp.11-18
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• 2015

PURPOSES : The purpose of this thesis is to evaluate the effectiveness of an active noise cancellation (ANC) system in reducing the traffic noise level against frequencies from the predictive model developed by previous research. The predictive model is based on ISO 9613-2 standards using the Noble close proximity (NCPX) method and the pass-by method. This means that the use of these standards is a powerful tool for analyzing the traffic noise level because of the strengths of these methods. Traffic noise analysis was performed based on digital signal processing (DSP) for detecting traffic noise with the pass-by method at the test site. METHODS : There are several analysis methods, which are generally divided into three different types, available to evaluate traffic noise predictive models. The first method uses the classification standard of 12 vehicle types. The second method is based on a standard of four vehicle types. The third method is founded on 5 types of vehicles, which are different from the types used by the second method. This means that the second method not only consolidates 12 vehicle types into only four types, but also that the results of the noise analysis of the total traffic volume are reflected in a comparison analysis of the three types of methods. The constant percent bandwidth (CPB) analysis was used to identify the properties of different frequencies in the frequency analysis. A-weighting was applied to the DSP and to the transformation process from analog to digital signal. The root mean squared error (RMSE) was applied to compare and evaluate the predictive model results of the three analysis methods. RESULTS : The result derived from the third method, based on the classification standard of 5 vehicle types, shows the smallest values of RMSE and max and min error. However, it does not have the reduction properties of a predictive model. To evaluate the predictive model of an ANC system, a reduction analysis of the total sound pressure level (TSPL), dB(A), was conducted. As a result, the analysis based on the third method has the smallest value of RMSE and max error. The effect of traffic noise reduction was the greatest value of the types of analysis in this research. CONCLUSIONS : From the results of the error analysis, the application method for categorizing vehicle types related to the 12-vehicle classification based on previous research is appropriate to the ANC system. However, the performance of a predictive model on an ANC system is up to a value of traffic noise reduction. By the same token, the most appropriate method that influences the maximum reduction effect is found in the third method of traffic analysis. This method has a value of traffic noise reduction of 31.28 dB(A). In conclusion, research for detecting the friction noise between a tire and the road surface for the 12 vehicle types needs to be conducted to authentically demonstrate an ANC system in the Republic of Korea.

• 대한공업교육학회지
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• v.36 no.1
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• pp.115-130
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• 2011

When the hollow cylinder structure moves in underwater with high speed structural can be propagated from the end of the structure to the front side. This noise can reduce the sensitivity of the conformal array which installed in the surface of the cylinder. To reduce this noise propagation it is suggested to install two self-reduction rings at the surrounding of the cylinder which is 500mm in diameter and 840mm in length. The places of the two noise reduction rings are 120mm and 240mm point from the end of the structure. Two noise reduction rings reduced 10.1 % of maximum stress. When outside noise frequency applied to the structure from the 4kZ to 6kHz, 20dB noise reduction was calculated using 6 order polynomial equation. When outside noise frequency also applied to the structure with 200Hz, 500Hz, 900Hz, maximum sound pressure level point moved to the end of the structure. Most conformal sensors are fabricated at the front side of the structure. Based on the simulation results proposed two rings can be reduced noise propagation from the tail of the structure effectively.

• Journal of Korean Academy of Nursing
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• v.27 no.2
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• pp.433-443
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• 1997

Cardiac catheterization is a diagnostic procedure which is intrusive and anxiety provoking. Patient education and information offer have been suggested as effective nursing interventions to reduce patients' anxiety and stress. Main objectives of this study are : 1) to develop concrete objective information for patients undergoing cardiac catheterization : 2) to analyze the types of information included in the newly developed concrete objective information. The subjects of this study are 11 patients who were admitted to the CCU of a general hospital in Seoul. The subjects were provided with preparatory information about cardiac catheterization by using interview and a booklet. After the procedure, the subjects were asked to describe additional information which they suggest to be added into the booklet and the physical sensations felt during the procedure. The results of the study are summarized as follows : Most subjects were satisfied with the preparatory information that was provided by interview and the booklet before the procedure. But patients suggested several problems related to the content of the booklet. First, they reported difficulty to differentiate the terms -coronary angio gram and cardiac catheterization. Also, some patients expressed that they feared after reading the information about the incision of inguinal area. Subjects responded that the information about the direct process of the test did not reduce their anxiety and the information was not detail enough. Next, most subjects would want to know about the monitor and the sound from monitor. They said that they could not hear instructions from doctor or nurse during the procedure due to tension. Considering above response results, the need for more effective way to provide information, like visual and auditory information through video tape for giving information is suggested. Sensations related to the procedure were the smell coming from sterilization of inguinal area, stinging pain in groin when the doctor inserts a needle into artery, and the sensation of pressure and moving of vessels surrounding neck when the catheter was inserted and visualized on fluoroscopy. Besides, subject reported hot sensation and burning feeling in face and chest area, and nausea when dye is injected by hand. In the analysis of information content, there was 79% agreement on the actual units of analysis that were coded. In the analysis of type of information, procedural information was 60.4%. Concrete objective information was 28.1%. and other information was 11.5%. Agreement of the coders in categorizing the units of information was determined by using Cohen's kappa which corrects for chance agreement. Cohen's kappa was .84.

• Journal of Physiology & Pathology in Korean Medicine
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• v.22 no.1
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• pp.13-24
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• 2008

This Chapter mentioned Terror and Palpitation due to Fright(驚悸) and Hemorrhagic disease(血證). Terror and Palpitation due to FrightAcctually Terror(驚) is different from Palpitation(悸). Terror(驚) is one of the seven emotions. But in this case, It refer to the Palpitation and the uneasiness of mind due to one's hearing a strange sound of seeing a strange. Tremulous Pulse can be appear. So Terror(驚) is caused by Exopathic Factors(外因) and belongs to Excess syndrome(實證). Palpitaion(悸) is the sensation of plamus, palpitation and unrest not because of being frightened. It is usurally caused by the deficiency of Ki(氣) and blood(血). So Deep, Thready and weak pulse can be appear. So Palpitaion(悸) is caused by Endopathic Factors and belongs to Deficiency Syndrome. In this Chapter, Terror and Palpitation due to Fright(驚悸) treat with the Kyeji-ke-jakyak-ka-chokchil-moryu-yongkol-kuyuk-tang(桂枝去芍藥加蜀漆牡蠣龍骨救逆湯) and Banha-mahwang-hwan(半夏麻黃丸). There are two type in Hemorrhagic disease(血證). One is bleeding(出血) and another is blood stasis(瘀血). The contents which relate with the Hemorrhagic disease(血證) are Hematemisis(吐血), Rhinorrhagia, Hemafecia(下血). In hemorrhage pathological mechanisms, there are two mechanisms. One is that Fire and Heat(火熱) pressure blood. Another is that cold and deficiency(虛寒) disable Ki(氣) from keeping blood flowing within vessels. Blood stasis(瘀血) can be called Extravasated Blood(惡血), Coagulated Blood, Blood retention(蓄血,積血), Dead Blood(死血) and Emaciation due to Blood disorder(乾血). It refer to a morbid state of unsmooth circulation and blood stagnancy often resulting from Ki(氣) stagnation, Ki(氣) deficiency and accumulation of pathogenic coldness. The symptom of Blood stasis are 'Fullness sensation in the chest, Lip Flaccidity, Cyonotic Tongue and Dryness of Mouth'. And the man who have Blood stasis, want to rinse his mouth with the water, but he can't drink the water because there isn't interior Heat of Excess Type. The symptom of Cyonotic Tongue(舌靑) had influence on diagnosing Blood stasis(瘀血) in offspring.

• Journal of Energy Engineering
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• v.22 no.3
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• pp.287-293
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• 2013

This study was carried out to diminish the formation of scale in boilers which is one of the defect elements when they are operating. The defect relating to scale can cause a fatal impact on the explosion of boilers due to the overheating of their tubes, or it can affect the flow of water inside boilers with its bad circulation and result in a disparity of water inside the equipment. Heat transfer in the scale is low comparing to the boiler material, so it can lead to energy losses and has also impact on the global warming. In 2005, the Korean government introduced a system which requires boiler users to install the equipment which can prevent or eliminate the formation of scale to improve the management of water quality in boilers. The study on the techniques for preventing or eliminating the formation of scale started in 1821 and since then subsequently there have been lots of similar studies. The first one was about the scale reduction using potato starch. Since an ultrasonic scale preventer developed by a scientist from a Russian acoustic institute was introduced in1993, a variety of equipment of this kind have been disseminated in Korea. There has been a need to demonstrate the condition for the best performances of such equipment. Boilers are mostly composed of the main body and 288 the tube with a circular curved surface. I carried out a demonstration study on a circular tube which affects the scale defect the most among the boiler components. As a result of it, I found out the fact that the ultrasonic wave needs to reach a certain level of sound pressure and frequency to affect the formation of scale.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.38 no.12
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• pp.1057-1064
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• 2014

Recently, there has been a growing interest in sustainable energy. One method that has been used is an organic Rankine cycle using conventional turbine technology with a low-temperature waste heat source. A 200-kW organic Rankine cycle (ORC) system was designed for a waste heat recovery application using R245fa as the working fluid. A radial turbine running at 15,000 rpm was employed to generate more than 200 kW with an expansion ratio of nine. Because an ORC turbine uses a refrigerant as the working fluid, the ideal gas law was not employed to design the turbine. In addition, the complexity of the molecular structure of R245fa made it difficult to design the turbine. Because R245fa has an Ma value of one at a low velocity for the working fluid (about 1/3 of the speed of sound in air) at about $100^{\circ}C$, it easily reaches a supersonic flow condition with a small pressure expansion. To increase the efficiency of the turbine, a dual stage radial-type turbine with a subsonic speed was suggested. This paper will describe the design procedure and performance evaluation of the ORC turbine using R245fa.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.10
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• pp.415-424
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• 2019

In this paper, a minimum rotation radius was designed and fabricated to overcome the threshold so that elderly or disabled people who have difficulty moving can move and transfer safely and conveniently in a narrow room. In the indoor environment, where the sedentary culture develops, this study aimed to provide convenience for passengers with fracture diseases, geriatric diseases, and other knee and waist diseases. First, links, seats, armrests, covers, motors, batteries, chargers, controllers, etc. were attached to the frame so that they could be moved and lifted indoors. The product design and structure were designed considering the user's environment and physical characteristics, and IoT functions were added. A driving experiment was performed to confirm the operating performance of the manufactured indoor moving and lifting wheelchair. The performance tests, such as continuous running time, turning radius, maximum actuator load, maximum lift height, sound pressure level, minimum sensing distance of the driving aid sensor, interworking of server and app programs, device compatibility, and duty cycle error rate, were performed. As a result of the test, the built-in wheelchair could achieve the performance test target of each item and operate successfully.