• The Korean Journal of Air & Space Law and Policy
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• v.19 no.2
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• pp.9-53
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• 2004

This paper described the contents of theme entitled "Domestic Legislative Problems on the Civil Liability of Air Carrier in Korea" including the current example of fourteen countries' legislation ((1) Great Britain, (2) United States of America, (3) Canada, (4)European Union), (5) Germany, (6) France, (7) Italy, (8) Spain, (9) Swiss, (10) Australia, (11) Japan, (12) People's Republic of China, (13) Taiwan, (14) North Korea) relating to the aviation law or air transport law. Though the Korean and Japanese aviation act has provided only the public items such as (1) registration of aircraft, (2) persons engaged in aviation, (3) operation of aircraft, (4) aviation facilities including airport, (5) air transport business, (6) investigate of aircraft accidents etc., but they could not regulated the private items such as the legal relations of the air transport contract (1) air passenger ticket, (2) air luggage ticket, (3) airway bill, (4) liability of air carrier, (5) amount of compensation for damage caused by aircraft accidents, (6)jurisdiction, (7) arbitration, (8) limitation of action, (9) combined carriage, (10) carriage by air performed by an actual carrier other than contracting carrier, damage caused by aircraft to the third parties etc. in their aviation act until now. In order to solve speedily the legal problems on the limitation of air carrier's liability and long law suit and disputes between wrongdoers and survivors etc, it is necessary and desirable for us to enact a new "Draft for the Air Transport Act" including the abovementioned private items. I would like to propose personally and strongly the legislation of "Draft for the Air Transport Act" in Korea in emphasizing the importance of ensuring protection of the interests of consumers air passengers and shippers in carriage by air and the need for equitable compensation between air carriers and survivors caused by the aircraft accidents such as the German Air Transport Act (Luftverkerhrsgesetz).

• The Korean Journal of Nuclear Medicine Technology
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• v.19 no.2
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• pp.74-80
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• 2015

Purpose Breast lymphoscintigraphy is an important technique to present for body surface precisely, which shows a lymph node metastasis of malignant tumors at an early stage and is performed before and after surgery in patients with breast cancer. In this study, we evaluated several methods of body outline imaging to present exact location of lesions, as well as compared respective exposure doses. Materials and Methods RANDO phantom and SYMBIA T-16 were used for obtaining imaging. A lesion and an injection site were created by inserting a point source of 0.11 MBq on the axillary sentinel lymph node and 37 MBq on the right breast, respectively. The first method for acquiring the image was used by drawing the body surface of phantom for 30 sec using $Na^{99m}TcO_4$ as a point source. The second, the image was acquired with $^{57}Co$ flood source for 30 seconds on the rear side and the left side of the phantom, the image as the third method was obtained using a syringe filled with 37 MBq of $Na^{99m}TcO_4$ in 10 ml of saline, and as the fourth, we used a photon energy and scatter energy of $^{99m}Tc$ emitting from phantom without any addition radiation exposure. Finally, the image was fused the scout image and the basal image of SPECT/CT using MATLAB$^{(R)}$ program. Anterior and lateral images were acquired for 3 min, and radiation exposure was measured by the personal exposure dosimeter. We conducted preference of 10 images from nuclear medicine doctors by the survey. Results TBR values of anterior and right image in the first to fifth method were 334.9 and 117.2 ($1^{st}$), 266.1 and 124.4 ($2^{nd}$), 117.4 and 99.6 ($3^{rd}$), 3.2 and 7.6 ($4^{th}$), and 565.6 and 141.8 ($5^{th}$). And also exposure doses of these method were 2, 2, 2, 0, and $30{\mu}Sv$, respectively. Among five methods, the fifth method showed the highest TBR value as well as exposure dose, where as the fourth method showed the lowest TBR value and exposure dose. As a result, the last method ($5^{th}$) is the best method and the fourth method is the worst method in this study. Conclusion Scout method of SPECT/CT can be useful that provides the best values of TBR and the best score of survey result. Even though personal exposure dose when patients take scout of SPECT/CT was higher than another scan, it was slight level comparison to 1 mSv as the dose limit to non-radiation workers. If the scout is possible to less than 80 kV, exposure dose can be reduced, and also useful lesion localization provided.

• The Korean Journal of Nuclear Medicine Technology
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• v.14 no.2
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• pp.172-176
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• 2010

Purpose: The patients' moves occurred at PET/CT scan will cause the decline of correctness in results by resulting in inconsistency of Attenuation Correction (AC) and effecting on quantitative evaluation. This study has evaluated the utility of reconstruction method using AC position changing method when having inconsistency of AC depending on the position change of emission scan after transmission scan in obtaining PET/CT 3D image. Materials and Methods: We created 1 mL syringe injection space up to ${\pm}2$, 6, 10 cm toward x and y axis based on central point of polystyrene ($20{\times}20110$ cm) into GE Discovery STE16 equipment. After projection of syringe with $^{18}F$-FDG 5 kBq/mL, made an emission by changing the position and obtained the image by using AC depending on the position change. Reconstruction method is an iteration reconstruction method and is applied two times of iteration and 20 of subset, and for every emission data, decay correction depending on time pass is applied. Also, after setting ROI to the position of syringe, compared %Difference (%D) at each position to radioactivity concentrations (kBq/mL) and central point. Results: Radioactivity concentrations of central point of emission scan is 2.30 kBq/mL and is indicated as 1.95, 1.82 and 1.75 kBq/mL, relatively for +x axis, as 2.07, 1.75 and 1.65 kBq/mL for -x axis, as 2.07, 1.87 and 1.90 kBq/mL for +y axis and as 2.17, 1.85 and 1.67 kBq/mL for -y axis. Also, %D is yield as 15, 20, 23% for +x axis, as 9, 23, 28% for -x axis, as 12, 21, 20% for +y axis and as 8, 22, 29% for -y axis. When using AC position changing method, it is indicated as 2.00, 1.95 and 1.80 kBq/mL, relatively for +x axis, as 2.25, 2.15 and 1.90 kBq/mL for -x axis, as 2.07, 1.90 and 1.90 kBq/mL for +y axis, and as 2.10, 2.02, and 1.72 kBq/mL for -y axis. Also, %D is yield as 13, 15, 21% for +x axis, as 2, 6, 17% for -x axis, as 9, 17, 17% for +y axis, and as 8, 12, 25% for -y axis. Conclusion: When in inconsistency of AC, radioactivity concentrations for using AC position changing method increased average of 0.14, 0.03 kBq/mL at x, y axis and %D was improved 6.1, 4.2%. Also, it is indicated that the more far from the central point and the further position from the central point under the features that spatial resolution is lowered, the higher in lowering of radioactivity concentrations. However, since in actual clinic, attenuation degree increases more, it is considered that when in inconsistency, such tolerance will be increased. Therefore, at the lesion of the part where AC is not inconsistent, the tolerance of radioactivity concentrations will be reduced by applying AC position changing method.

• Journal of Chest Surgery
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• v.36 no.12
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• pp.929-936
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• 2003

We analysed the surgical outcomes of immediate reoperations after mitral valve repair. Material and Method: Eighteen patients who underwent immediate reoperation for failed mitral valve repair from April 1995 through July 2001 were reviewed retrospectively. There were 13 female patients. The mitral valve disease was regurgitation (MR) in 12 patients, stenosis (MS) in 3, and mixed lesion in 3. The etiologies of the valve disease were rheumatic in 9 patients, degenerative in 8, and endocarditis in 1. The causes of reoperation was residual MR in 13 patients, residual MS in 4, and rupture of left ventricle in 1. Fourteen patients had rerepair for residual mitral lesions (77.8%) and four underwent replacement. Result: There was no early death. After mean follow-vp of 33 months, there was one late death. Echocardiography revealed no or grade 1 of MR (64.3%) in 9 patients and no or mild MS in 11 patients (78,6%). Reoperation was done in one patient. The cumulative survival and freedom from valve-related reoperation at 6 years were 94% and 90%, respectively. The cumulative freedom from recurrent MR and MS at 4 years were 56% and 44%, respectively. Conclusion: This study suggests that immediate reoperation for failed mitral valve repair offers good early and intermediate survival, and mitral valve rerepair can be successfully performed in most of patients. However, because mitral rerepair have high failure rate, especially in rheumatic valve disease, adequate selections of valvuloplasty technique and indication are important to reduce the failure rate of mitral rerepair.

• Magazine of the Korean Society of Agricultural Engineers
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• v.13 no.3
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• pp.2322-2341
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• 1971

The studies were conducted to determine the methods of irrigation control which is not only able to save the irrigation water as a adaptable measures for the insufficient irrigation water and the drought but also increase the yields of rice, in the paddy field which shows over percolating tendency through the couple years of 1968 and 1969 at Suwon. These experiments were carried with late maturing rice variety, Norim No. 6 and the major treatments in this experiments were filling the clay under surface soil, periodic irrigation and lining the Vinyl under the surface soil and three replicated completely randomized design was employed. Results obtained will be summarzed as follows. 1. Through the couple years, the plots tilled the clay under 15cm of the surface soil saved the irrigation water by 364% to 45% and 78% to 88% respectively. Particulary, the plot of filling the clay with 9cm thick under 15cm of the surface soil, saved the amount of irrigation water by 45% to 88% and also increased yields by 12% to 20% through the couple years. 2. The plots in which amount of 40mm of irrigation water is irrigated periodically from 5 to 8 days at the stages of tillering and ripening, saved theamount of irrigation water by 41% to 55% and also increased yields by 10% to 16% respectively through the couple years. 3. The plot lined the Vinyl under 15cm of the surface soil, saved the amount of irrigation water by 75% to 88% in accordance with the size of hole. The plot of lining the Vinyl with $3cm/m^2$ hole yielded almost same as the check plot, but in the case of lesser hole than above yielded less. 4. The plots inserted the Vinyl paper in 57cm depth and with 6cm height from the soil surface around the plot to prevent the ridge percolation reduced the amount of percolation by 25% to 33%. 5. The plot filled the wheat straw with 6cm thick under 15cm of the surface soil increased yields by 30% in former year but opposite results were gained in later year. 6. Generally, yields and yield components such as number of spikes of spikes per hill and number of grains per spike were decreased in 1969. These faots are considered to depend upon the rainy and cold weather in the stages of vigorous tillering and less sunshine in the stages of ripening. 7. The variation of characters among the plots will be summarized as follows. (1) Tallerplant height was found in the plots of clay filling and irrigation control. (2) longer culm length and higher yields were founds in the plots filled the clay with 9cm thick and controled the irrigation periodically froir 7 to 8 days. (3) Length of spike increased generally with yields but opposite tendency was found also. (4) Number of spikes per hill increased with yields in the plots of irrigation control. (5) Number of grains per spike increased with yields in the plots filled the clay with 9cm thick and controled irrigation periodically from 5 to 8 days. (6) Tendency of variation of 1000 grain weight is similar to Number of grains per spike. (7) Percentage of complete grains increased in the plot of clay filling and irrigation control.

• Journal of Chest Surgery
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• v.31 no.10
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• pp.939-944
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• 1998

Background: The sugical results of the Cox-Maze procedure (CMP) for lone atrial fibrillation(AF) have proven to be exellent. However, those for AF associated with mitral valve(MV) disease have been reported to be a little inferior. Materials and methods: To assess the efficacy and safety of the CMP as a combined procedure with MV operation, we studied retrospectively our experiences. Between April 1994 and October 1997, we experienced 70 (23 males, 47 females) cases of CMP concomitantly with MV operation. Results: The etiologies of MV disease were rheumatic in 67 and degenerative in 3 cases. The mean duration of AF before sugery was 66$\pm$70 months. Fifteen patients had the past medical history of thromboembolic complications, and left atrial thrombi were identified at operation in 24 patients. Twelve cases were reoperations. Aortic cross clamp (ACC) time was mean 151$\pm$44 minutes, and cardiopulmonary bypass (CPB) time was mean 246$\pm$65 minutes. Concomitant procedures were mitral valve replacement (MVR) in 19, MVR and aortic valve replacement (AVR) in 14, MVR and tricupid annuloplasty (TAP) in 8, MVR with AV repair in 3, MV repair in 11, MVR and coronary artery bypass grafting (CABG) in 2, MVR and AVR and CABG in 1, redo-MVR in 10, redo-MVR and redo-AVR in 2 patients. The rate of hospital mortality was 1.4%(1/70). Perioperative recurrence of AF was seen in 44(62.9%), and atrial tachyarrhythmias in 10(14.3%), low cardiac output syndrome in 4(5.7%), postoperative bleeding that required mediastinal exploration in 4(5.7%) patients. Other complications were acute renal failure in 2, aggravation of preoperative hemiplegia in 1, and transient delirium in 1 patient. We followed up all the survivors for 16.4 months(3-44months) on an average. Sinus rhythm has been restored in 65(94.2%) patients. AF has been controlled by operation alone in 73.9% and operation plus medication in 20.3%. Two patients needed permanent pacemaker implantation; one with sick sinus syndrome, and the other with tachycardia- bradycardia syndrome. Only two patients remained in AF. We followed up our patients with transthoracic echocardiography to assess the atrial contractilities and other cardiac functions. Right atrial contractility could be demonstrated in 92% and left atrial contractility in 53%.We compared our non-redo cases with redo cases. Although the duration of AF was significantly longer in redo cases, there was no differences in ACC time, CPB time, postoperative bleeding amount and sinus conversion rate. Conclusions: In conclusion, the CMP concomitant with MV operation demonstrated a high sinus conversion rate under the acceptable operative risk even in case of reoperation.

• Magazine of the Korean Society of Agricultural Engineers
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• v.13 no.1
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• pp.2206-2217
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• 1971

Spillway and discharge channel of reservoirs require the Control of Large volume of water under high pressure. The energies at the downstream end of spillway or discharge channel are tremendous. Therefore, Some means of expending the energy of the high-velocity flow is required to prevent scour of the riverbed, minimize erosion, and prevent undermining structures or dam it self. This may be accomplished by Constructing an energy dissipator at the downstream end of spillway or discharge channel disigned to dissipated the excessive energy and establish safe flow Condition in the outlet channel. There are many types of energy dissipators, stilling basins are the most familar energy dissipator. In the stilling basin, most energies are dissipated by hydraulic jump. stilling basins have some length to cover hydraulic jump length. So stilling basins require much concrete works and high construction cost. Flip bucket type energy dissipators require less construction cost. If the streambed is composed of firm rock and it is certain that the scour will not progress upstream to the extent that the safety of the structure might be endangered, flip backet type energy dissipators are the most recommendable one. Following items are tested and studied with bucket radius, $R=7h_2$,(medium of $4h_2{\geqq}R{\geqq}10h_2$). 1. Allowable upstream channel slop of bucket. 2. Adequate bucket lip angle for good performance of flip bucket. Also followings are reviwed. 1. Scour by jet flow. 2. Negative pressure distribution and air movement below nappe flow. From the test and study, following results were obtained. 1. Upstream channel slope of bucket (S=H/L) should be 0.25<H/L<0.75 for good performance of flip bucket. 2. Adequated lip angle $30^{\circ}{\sim}40^{\circ}$ are more reliable than $20^{\circ}{\sim}30^{\circ}$ for the safety of structures.

• The Journal of Korean Society for Radiation Therapy
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• v.27 no.2
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• pp.97-106
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• 2015

Purpose : This study evaluate the thermal changes caused by use of the chemoport for drug administration and blood sampling during radiofrequency hyperthermia. Materials and Methods : 20cm size of the electrode radio frequency hyperthermia (EHY-2000, Oncotherm KFT, Hungary) was used. The materials of the chemoport in our hospital from currently being used therapy are plastics, metal-containing epoxy and titanium that were made of the diameter 20 cm, height 20 cm insertion of the self-made cylindrical Agar phantom to measure the temperature. Thermoscope(TM-100, Oncotherm Kft, Hungary) and Sim4Life (Ver2.0, Zurich, Switzerland) was compared to the actual measured temperature. Each of the electrode measurement position is the central axis and the central axis side 1.5 cm, 0 cm(surface), 0.5 cm, 1.8 cm, 2.8 cm in depth was respectively measured. The measured temperature is $24.5{\sim}25.5^{\circ}C$, humidity is 30% ~ 32%. In five-minute intervals to measure the output power of 100W, 60 min. Results : In the electrode central axis 2.8 cm depth, the maximum temperature of the case with the unused of the chemoport, plastic, epoxy and titanium were respectively $39.51^{\circ}C$, $39.11^{\circ}C$, $38.81^{\circ}C$, $40.64^{\circ}C$, simulated experimental data were $42.20^{\circ}C$, $41.50^{\circ}C$, $40.70^{\circ}C$, $42.50^{\circ}C$. And in the central axis electrode side 1.5 cm depth 2.8 cm, mesured data were $39.37^{\circ}C$, $39.32^{\circ}C$, $39.20^{\circ}C$, $39.46^{\circ}C$, the simulated experimental data were $42.00^{\circ}C$, $41.80^{\circ}C$, $41.20^{\circ}C$, $42.30^{\circ}C$. Conclusion : The thermal variations were caused by radiofrequency electromagnetic field surrounding the chemoport showed lower than in the case of unused in non-conductive plastic material and epoxy material, the titanum chemoport that made of conductor materials showed a slight differences. This is due to the metal contents in the chemoport and the geometry of the chemoport. And because it uses a low radio frequency bandwidth of the used equipment. That is, although use of the chemoport in this study do not significantly affect the surrounding tissue. That is, because the thermal change is insignificant, it is suggested that the hazard of the chemoport used in this study doesn't need to be considered.

• Progress in Medical Physics
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• v.26 no.3
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• pp.160-167
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• 2015

Radiation exposure from medical diagnostic imaging procedures to patients is one of the most significant interests in diagnostic x-ray system. A miniature x-ray intraoral tube was developed for the first time in the world which can be inserted into the mouth for imaging. Dose evaluation should be carried out in order to utilize such an imaging device for clinical use. In this study, dose evaluation of the new x-ray unit was performed by 1) using a custom made in vivo Pig phantom, 2) determining exposure condition for the clinical use, and 3) measuring patient dose of the new system. On the basis of DRLs (Diagnostic Reference Level) recommended by KDFA (Korea Food & Drug Administration), the ESD (Entrance Skin Dose) and DAP (Dose Area Product) measurements for the new x-ray imaging device were designed and measured. The maximum voltage and current of the x-ray tubes used in this study were 55 kVp, and 300 mA. The active area of the detector was $72{\times}72mm$ with pixel size of $48{\mu}m$. To obtain the operating condition of the new system, pig jaw phantom images showing major tooth-associated tissues, such as clown, pulp cavity were acquired at 1 frame/sec. Changing the beam currents 20 to $80{\mu}A$, x-ray images of 50 frames were obtained for one beam current with optimum x-ray exposure setting. Pig jaw phantom images were acquired from two commercial x-ray imaging units and compared to the new x-ray device: CS 2100, Carestream Dental LLC and EXARO, HIOSSEN, Inc. Their exposure conditions were 60 kV, 7 mA, and 60 kV, 2 mA, respectively. Comparing the new x-ray device and conventional x-ray imaging units, images of the new x-ray device around teeth and their neighboring tissues turn out to be better in spite of its small x-ray field size. ESD of the new x-ray device was measured 1.369 mGy on the beam condition for the best image quality, 0.051 mAs, which is much less than DRLs recommended by IAEA (International Atomic Energy Agency) and KDFA, both. Its dose distribution in the x-ray field size was observed to be uniform with standard deviation of 5~10 %. DAP of the new x-ray device was $82.4mGy*cm^2$ less than DRL established by KDFA even though its x-ray field size was small. This study shows that the new x-ray imaging device offers better in image quality and lower radiation dose compared to the conventional intraoral units. In additions, methods and know-how for studies in x-ray features could be accumulated from this work.

• Tuberculosis and Respiratory Diseases
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• v.47 no.5
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• pp.601-608
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• 1999

Background: Tuberculous pleural effusion responds well to the anti-tuberculosis agents in general, so no further aggressive therapeutic managements to drain the tuberculous effusion is necessary except in case of diagnostic thoracentesis. But in clinical practice, we often see some patients who later decortication need due to dyspnea caused by pleural thickening despite the completion of anti-tuberculosis therapy in the patients with tuberculous effusion. Especially, the patients with loculated tuberculous effusion might have increased chance of pleural thickening after treatment. The purpose of this study was that intrapleural urokinase instillation could reduce the pleural thickening in the treatment of loculated tuberculous pleural effusion. Methods: Thirty-seven patients initially diagnosed as having loculated tuberculous pleural effusion were randomly assigned to receive either the combined treatment of urokinase instillation and anti-tuberculosis agents(UK group) and anti-tuberculosis agents(Non-UK group) alone. The 16 patients in UK group received a single radiographically guided pig-tail catheter ranging in size from 10 to 12 French. 100,000 units of urokinase was dissolved in 150 ml of normal saline and instilled into the pleural cavity via pig-tail catheter every day, also this group was treated with anti-tuberculosis agents. While the 21 patients in Non-UK group were treated with anti-tuberculosis agents only except diagnostic thoracentesis. Then we evaluated the residual pleural thickening after treatment for their loculated tuberculous pleural effusion between the two groups. Also the duration of symptoms and the pleural fluid biochemistry like WBC counts, pH, lactic dehydrogenase(LDH), glucose, proteins, and adenosine deaminase(ADA) were compared. Results: 1) The residual pleural thickening(RPT)($5.08{\pm}6.77$ mm) of UK group was significantly lower than that($20.3222{\pm}26.37$ mm) of Non-UK group(P<0.05). 2) The duration of symptoms before anti-tuberculosis drug therapy of patients with RPT$\geq$10 mm($5.23{\pm}3.89$ wks) was significantly longer than the patients with RPT<10 mm($2.63{\pm}1.99$ wks)(P<0.05). 3) There were no significant differences in the pleural fluid findings like WBC count, glucose, LDH, proteins, pH, ADA between the patients with RPT$\geq$10 mm and the patients with RPT<10 mm. Conclusion : The treatment of loculated tuberculous pleural effusion with the urokinase instillation via percutaneous transthoraic catheter was effective to reduce the pleural thickening.