• Journal of Chest Surgery
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• v.18 no.4
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• pp.844-848
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• 1985

Mediastinal tumors which are originated in mediastinum or probably metastasized from other organs have long fascinated the surgeon because of difficulty of diagnosis and treatment. This report is the analysis of the 26 cases of mediastinal tumors, experienced in the Department of the Thoracic and Cardiovascular Surgery, Chosun University Hospital from January 1978 to January 1985. The result are as follows; 1. The age distribution was 10 months to 68 years old and the average mean age was 34.7 years old. 2. Subjective symptom were as follows: Dyspnea [69.2%], Coughing [42.3%], Chest pain [30.8%], Back pain [15.4%] and Numbness of extremities [15.4%]. Objective signs were as follows: Decreased breathing sound [53.3%], Pleural effusion and hemothorax [34.6%], Palpable neck mass [34.6%], SVC Syndrome [19.4%] and Bloody sputum [15.4%]. But, there were no definitive symptoms in 2 cases. 3. The malignant tumors were 19 cases [73.1%]. 4. The germ cell tumors were 2 cases [7.7%], the neurogenic tumor were 3 cases [11.5%], lymphoma were 8 cases [30.8%], thymoma were 2 cases [7.7%], mesenchymal tumor was 1 case [3.8%], cyst was 1 case [3.8%] and carcinoma were 5 cases [19.2%] among the 23 cases, histologically analyzed. 5. The successful complete removal was done in 5 cases among 7 cases of benign tumors. In malignant cases, the surgical removal had been 7 cases and inoperable cases were treated to radiation and chemotherapy.

• The Journal of the Acoustical Society of Korea
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• v.22 no.3
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• pp.217-223
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• 2003

A novel cooling method induced by acoustic streaming generated by ultrasonic vibration at 30㎑ is presented. Ultrasonic vibration is obtained by piezoelectric devices and the maximum vibration amplitude of 50 m is achieved by including a horn, mechanical vibration amplifier in the system and making the complete system resonate. To investigate the enhancement of heat transfer capability of acoustic streaming, the temperature variations of heat source and air in the vicinity of heat source are measured in real-time. It is observed that acoustic streaming is instantly induced by ultrasonic vibration, resulting in the significant temperature drop due to the bulk air flow caused by acoustic streaming. In addition, it is observed that the cooling effect on the heat source is maximized when the gap between the ultrasonic vibrator and heat source coincides with the multiples of half-wavelength of the ultrasonic wave. This fact results from the resonance of the sound wave. The theoretical analysis of the dependence on the gap is also accomplished and verified by experiment. The advantage of the proposed cooling method by acoustic streaming is noise-free due to the ultrasonic vibration and maintenance-free because of the absence of moving parts. Moreover. This cooling method can be utilized to the nano and micro-electro mechanical systems, where the fan-based conventional cooling method can not be employed.

• Journal of the Korean Society of Laryngology, Phoniatrics and Logopedics
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• v.21 no.1
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• pp.42-47
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• 2010

Backgrounds and Objects: Carcinoma of the tongue is the most common cancer of the oral cavity. A primary treatment strategy includes surgery and/or radiotherapy. Resection of the tongue often results in speech dysfunction, which depends on the site and extent of resection, type of reconstruction, and the mobility of remaining tongue. This study aimed to evaluate the characteristics of articulation errors that were resulted from the partial glossectomy without free flap reconstruction. Materials & Method : Articulation evaluations including speech intelligibility and percent of correct consonants (PCC) were performed for 24 patients who underwent partial glossectomy for their T1 or T2 tongue cancer. Mobility of the tongue, size of the resected tongue, and the history of adjuvant radiotherapy were analyzed for their relationship with the results of articulation evaluation. Results: Speech intelligibility score was $6.4{\pm}0.9$ (on 7-point scale) and overall PCC was 96.9%. There were close relationships between the size of resection and limitations in the tongue mobility, especially in "protrusion and elevation (r=-0.687)" and "retroflexion (r=-0.775)". Errors in "alveolar fricatives" and "palatal affricates" were also closely related with the size of resection (r=-0.537 and -0.538, respectively). PCC for "liquid sound" /r/ was 83.2%, which was closely related with the history of radiation therapy. Conclusion : Overall articulatory function was satisfactory in cases of early tongue cancer after partial glossectomy of a limited volume without flap reconstruction. However, the size of resection and the history of radiation therapy were closely related to the limitations in some types of tongue mobility and the resultant articulation errors.

• Journal of the Korean Society for Nondestructive Testing
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• v.20 no.6
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• pp.538-544
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• 2000

A phased array ultrasonic nondestructive inspection system is being developed to obtain images of the interior of steel structures by modifying a medical ultrasound imaging system. The medical system consists of 64 individual transceiver channels that can drive 128 array elements. Several modifications of the system were required mainly due to the change of sound speed. It was necessary to fabricate array transducers for steel structure and to obtain A-scan signal that is necessary for the nondestructive testing. Boundary diffraction wave model was used for the prediction of radiation beam field from array transducers, which provided guidelines to design array transducers. And a RF data acquisition board was fabricated for the A-scan signal acquisition along a selected un line within an image. For the proper beam forming in the transmission and reception for steel structure, delay time was controlled. To demonstrate the performance of the developed system and fabricated transducers, images of artificial specimens and A-scan signals for selected scan lines were obtained in a real time fashion.

• Korean Journal of Food Science and Technology
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• v.32 no.5
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• pp.1051-1057
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• 2000

Gamma irradiation was applied to develop fermented shrimp product with lower salt concentration, high sensory quality and storage stability. Shrimp was prepared with 15 and 20% of salt and fermented at $15^{\circ}C$. The sample was irradiated for 15% added salt at the 4th week and for 20% at the 6th week during fermentation with 0, 5 and 10 kGy absorbed doses. The irradiation was applied at optimum stage of fermentation determined when the content of amino nitrogen(AN) arrived approximately 400 mg%. Chemical properties such as amino nitrogen(AN), volatile base nitrogen(VBN), trimethylamine(TMA) and neutral protease activity were examined during whole fermentation. The AN, VBN, TMA and protease activity were not affected immediately after gamma irradiation. The more NaCl concentrations and irradiation dose, the less content of chemical compounds and protease activity was found. From the results of chemical properties, it was concluded that fermented shrimp with 15% of salt and irradiated at 10 kGy before optimum fermentation, or 20% and 5 kGy or above were maintained the sound quality during storage compared with the control.

• Journal of the Korean earth science society
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• v.23 no.8
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• pp.676-682
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• 2002

The concept of sensible temperature in winter is an attempt to quantify the sensation of cold by dry-bulb temperature combined with wind speed. Siple-Passel’s windchill equivalent temperature originated in experiments that are not conformable to various human conditions. Therefore, many investigators have found the flaws which are listed. Steadman’s model is based on the concept of thermal equilibrium and more sound and more representative of human conditions. But no classifications exist for Steadman’s windchill equivalent temperature, yet. The JAG/TI-model which was developed by US and Canada is more accurate, easy to understand and reflects human beings by conducting experiments using human volunteers but didn't take into account solar radiation, wet condition and physical state of the individual. Because of individual differences in people’s age, activity, health, metabolic rate, etc., no experimental evidence exists to suggest whether Siple-Passel’s, Steadman’s and JAG/TI-model’s windchill equivalent temperature is more applicable to the majority of people. Therefore we need the windchill model which is best applicable to Korean Army.

• Journal of Advanced Marine Engineering and Technology
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• v.38 no.7
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• pp.923-928
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• 2014

Communication underwater is severely limited when compared to communications in air because water is essentially opaque to electromagnetic radiation except in visible range. Acoustic systems are capable of long range communication, but offer limited data rates and significant latency due to the speed of sound in water. On the other hand, optical wireless communication has been proposed as one of the best alternatives to meet the requirements of the underwater observation and subsea monitoring systems. It will help In this study, we are developing an underwater optical communication system that integrates with a depot ship floating on the water. An interface between LED lighting communication system and Bluetooth module is presented to support the underwater-to-air communications. Error free image and text transmission at 3 m of water were achieved at bit rates of 230.4 kbps. This development effort will enhance infrastructure to efficiently interconnect between underwater wireless systems and command ship networks for underwater monitoring.

• Journal of Chest Surgery
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• v.24 no.3
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• pp.245-252
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• 1991

For the purpose of evaluation of clinical characteristics and histopathological properties in mediastinal tumors and cysts, 50 patients with mediastinal tumors and cysts treated at the department of thoracic and cardiovascular surgery in Chosun University Hospital during the period from January, 1978 to Mach, 1990 were reviewed. The results of this cases analysis were as follows; 1. of all 50 mediastinal tumors and cysts, 27 patients were male and 23 patients were female. There was no sex preference. The age distribution was from 10 months to 84 years, and mean age was 37 years old, and no age preference. 2. Subjective symptoms were as follows : Dyspnea[54%], Chest pain[44%], Coughing [34%] Fever[16%] and General malaise[12%]. Objective signs were as follows: Decreased breathing sound[46%], Pleural effusion and hemothorax[32%], Palpable neck mass[24%] and SVC syndrome[14%]. But, there were no definitive symptoms in 5 cases[10%]. 3. The most frequently encountered tumors were teratodermoid tumors[26%] followed by lymphomas[22%], thymomas[12%] and benign cysts[8%] in decreasing order of frequency. 4. Based on the subdivision of the mediastinum, 44% of the tumors were in the anterior mediastinum, 24% in the middle mediastinum, 18% in the superior mediastinum and 14% in the posterior mediastinum. 5. The malignant tumors were 25 cases[50%]. 6. The successful removal was possible in all the benign mediastinal tumors and cysts. In malignant cases, the surgical removal had been 12 cases and inoperable cases were treated to radiation and chemotherapy. 7. Postoperative complications were bleeding, wound infection, pneumothorax and vocal cord paralysis. The recurrence was 3 cases. 8. The most frequent mediastinal tumor in the west is neurogenic tumor but is teratoma in Korea.

• Archives of Craniofacial Surgery
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• v.17 no.4
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• pp.198-201
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• 2016

Background: Zygomatic arch is a bony arch constituting the lateral midface, which consists of 25% of all midface fractures. There are a number of ways to evaluate the extent of zygomatic arch fracture. Some authors have reported successful treatment outcomes using ultrasound (U/S). To add to the previous methods, we have considered ways to accurately display the location of the fracture line while using U/S with 23 gauge needle marking. We introduce our method, which provided satisfactory results for reduction using a portable U/S, and it can evaluate the fracture line simultaneously when reduction of an isolated zygomatic arch fracture is necessary, and needle marking, which can easily point out the fracture line on U/S. Methods: We studied 21 patients with an isolated zygomatic arch fracture who underwent closed reduction using U/S and needle marking between 2013 and 2015. Results: We achieved satisfactory results in all our cases with respect to reduction by using the Dingman elevator after performing a temporal approach incision, while confirming relative positioning between needle marking and zygomatic fracture at the same time, after insertion of a 23 gauge needle in the skin above the zygomatic arch fracture line parallel to it. Conclusion: We treated 21 patients with an isolated zygomatic arch fracture using U/S and the needle marking method, which provided satisfactory results because the extent of reduction of the fracture could be evaluated in real-time during the operation and exposure to radiation was reduced.

• Progress in Medical Physics
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• v.24 no.3
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• pp.183-190
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• 2013

Recently, the photoacoustic imaging system has been widely and intensively developed, and has been shown the possibility of diagnosis for early stage cancer. In this study, we developed a photoacoustic tomography imaging system with a commercial ultra sound device and a linear array probe. A tube phantom and a chicken breast phantom was made for the possibility of a system as a breast cancer detection. A moving average filter and a band pass filter with 3~6 MHz bandwidth were developed for background noise elimination before delay-and-sum beamforming algorithm was used for image reconstruction. As a result, we showed that some signal processing procedure before beamforming was effective for the photoacoustic image reconstruction.