• Title/Summary/Keyword: Conversion Rate

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Efficacy and Accuracy of Patient Specific Customize Bolus Using a 3-Dimensional Printer for Electron Beam Therapy (전자선 빔 치료 시 삼차원프린터를 이용하여 제작한 환자맞춤형 볼루스의 유용성 및 선량 정확도 평가)

  • Choi, Woo Keun;Chun, Jun Chul;Ju, Sang Gyu;Min, Byung Jun;Park, Su Yeon;Nam, Hee Rim;Hong, Chae-Seon;Kim, MinKyu;Koo, Bum Yong;Lim, Do Hoon
    • Progress in Medical Physics
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    • v.27 no.2
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    • pp.64-71
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    • 2016
  • We develop a manufacture procedure for the production of a patient specific customized bolus (PSCB) using a 3D printer (3DP). The dosimetric accuracy of the 3D-PSCB is evaluated for electron beam therapy. In order to cover the required planning target volume (PTV), we select the proper electron beam energy and the field size through initial dose calculation using a treatment planning system. The PSCB is delineated based on the initial dose distribution. The dose calculation is repeated after applying the PSCB. We iteratively fine-tune the PSCB shape until the plan quality is sufficient to meet the required clinical criteria. Then the contour data of the PSCB is transferred to an in-house conversion software through the DICOMRT protocol. This contour data is converted into the 3DP data format, STereoLithography data format and then printed using a 3DP. Two virtual patients, having concave and convex shapes, were generated with a virtual PTV and an organ at risk (OAR). Then, two corresponding electron treatment plans with and without a PSCB were generated to evaluate the dosimetric effect of the PSCB. The dosimetric characteristics and dose volume histograms for the PTV and OAR are compared in both plans. Film dosimetry is performed to verify the dosimetric accuracy of the 3D-PSCB. The calculated planar dose distribution is compared to that measured using film dosimetry taken from the beam central axis. We compare the percent depth dose curve and gamma analysis (the dose difference is 3%, and the distance to agreement is 3 mm) results. No significant difference in the PTV dose is observed in the plan with the PSCB compared to that without the PSCB. The maximum, minimum, and mean doses of the OAR in the plan with the PSCB were significantly reduced by 9.7%, 36.6%, and 28.3%, respectively, compared to those in the plan without the PSCB. By applying the PSCB, the OAR volumes receiving 90% and 80% of the prescribed dose were reduced from $14.40cm^3$ to $0.1cm^3$ and from $42.6cm^3$ to $3.7cm^3$, respectively, in comparison to that without using the PSCB. The gamma pass rates of the concave and convex plans were 95% and 98%, respectively. A new procedure of the fabrication of a PSCB is developed using a 3DP. We confirm the usefulness and dosimetric accuracy of the 3D-PSCB for the clinical use. Thus, rapidly advancing 3DP technology is able to ease and expand clinical implementation of the PSCB.

Clinical Outcomes of Off-pump Coronary Artery Bypass Grafting (심폐바이패스 없는 관상동맥우회술의 임상성적)

  • Shin, Je-Kyoun;Kim, Jeong-Won;Jung, Jong-Pil;Park, Chang-Ryul;Park, Soon-Eun
    • Journal of Chest Surgery
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    • v.41 no.1
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    • pp.34-40
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    • 2008
  • Background: Off-pump coronary artery bypass grafting (OPCAB) shows fewer side effects than cardiopulmonary by. pass, and other benefits include myocardial protection, pulmonary and renal protection, coagulation, inflammation, and cognitive function. We analyzed the clinical results of our cases of OPCAB. Material and Method: From May 1999 to August 2007, OPCAB was performed in 100 patients out of a total of 310 coronary artery bypass surgeries. There were 63 males and 37 females, from 29 to 82 years old, with a mean age of $62{\pm}10$ years. The preoperative diagnoses were unstable angina in 77 cases, stable angina in 16, and acute myocardial infarction in 7. The associated diseases were hypertension in 48 cases, diabetes in 42, chronic renal failure in 10, carotid artery disease in 6, and chronic obstructive pulmonary disease in 5. The preoperative cardiac ejection fraction ranged from 26% to 74% (mean $56.7{\pm}11.6%$). Preoperative angiograms showed three-vessel disease in 47 cases, two-vessel disease in 25, one-vessel disease in 24, and left main disease in 23. The internal thoracic artery was harvested by the pedicled technique through a median sternotomy in 97 cases. The radial artery and greater saphenous vein were harvested in 70 and 45 cases, respectively (endoscopic harvest in 53 and 41 cases, respectively). Result: The mean number of grafts was $2.7{\pm}1.2$ per patient, with grafts sourced from the unilateral internal thoracic artery in 95 (95%) cases, the radial artery in 62, the greater saphenous vein in 39, and the bilateral internal thoracic artery in 2. Sequential anastomoses were performed in 46 cases. The anastomosed vessels were the left anterior descending artery in 97 cases, the obtuse marginal branch in 63, the diagonal branch in 53, the right coronary artery in 30, the intermediate branch in 11, the posterior descending artery in 9 and the posterior lateral branch in 3. The conversion to cardiopulmonary bypass occurred in 4 cases. Graft patency was checked before discharge by coronary angiography or multi-slice coronary CT angiography in 72 cases, with a patency rate of 92.9% (184/198). There was one case of mortality due to sepsis. Postoperative arrhythmias or myocardial in-farctions were not observed. Postoperative complications were a cerebral stroke in 1 case and wound infection in 1. The mean time of respirator care was $20{\pm}35$ hours and the mean duration of stay in the intensive care unit was $68{\pm}47$ hours. The mean amounts of blood transfusion were $4.0{\pm}2.6$ packs/patient. Conclusion: We found good clinical outcomes after OPCAB, and suggest that OPCAB could be used to expand the use of coronary artery bypass grafting.

The Current Status of the Warsaw Convention and Subsequent Protocols in Leading Asian Countries (아시아 주요국가(主要國家)들에 있어서의 바르샤바 체제(體制)의 적용실태(適用實態)와 전망(展望))

  • Lee, Tae-Hee
    • The Korean Journal of Air & Space Law and Policy
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    • v.1
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    • pp.147-162
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    • 1989
  • The current status of the application and interpretation of the Warsaw Convention and its subsequent Protocols in Asian countries is in its fredgling stages compared to the developed countries of Europe and North America, and there is thus little published information about the various Asian governments' treatment and courts' views of the Warsaw System. Due to that limitation, the accent of this paper will be on Korea and Japan. As one will be aware, the so-called 'Warsaw System' is made up of the Warsaw Convention of 1929, the Hague Protocol of 1955, the Guadalajara Convention of 1961, the Guatemala City Protocol of 1971 and the Montreal Additional Protocols Nos. 1,2,3 and 4 of 1975. Among these instruments, most of the countries in Asia are parties to both the Warsaw Convention and the Hague Protocol. However, the Republic of Korea and Mongolia are parties only to the Hague Protocol, while Burma, Indonesia and Sri Lanka are parties only to the Warsaw Convention. Thailand and Taiwan are not parties only to the convention or protocol. Among Asian states, Indonesia, the Phillipines and Pakistan are also parties to the Guadalajara Convention, but no country in Asia has signed the Guatemala City Protocol of 1971 or the Montreal Additional Protocols, which Protocols have not yet been put into force. The People's Republic of China has declared that the Warsaw Convention shall apply to the entire Chinese territory, including Taiwan. 'The application of the Warsaw Convention to one-way air carriage between a state which is a party only to the Warsaw Convention and a state which is a party only to the Hague Protocol' is of particular importance in Korea as it is a signatory only to the Hague Protocol, but it is involved in a great deal of air transportation to and from the united states, which in turn is a party only to the Warsaw Convention. The opinion of the Supreme Court of Korea appears to be, that parties to the Warsaw Convention were intended to be parties to the Hague Protocol, whether they actually signed it or not. The effect of this decision is that in Korea the United States and Korea will be considered by the courts to be in a treaty relationship, though neither State is a signatory to the same instrument as the other State. The first wrongful death claim in Korea related to international carriage by air under the Convention was made in Hyun-Mo Bang, et al v. Korean Air Lines Co., Ltd. case. In this case, the plaintiffs claimed for damages based upon breach of contract as well as upon tort under the Korean Civil Code. The issue in the case was whether the time limitation provisions of the Convention should be applicable to a claim based in tort as well as to a claim based in contract. The Appellate Court ruled on 29 August 1983 that 'however founded' in Article 24(1) of the Convention should be construed to mean that the Convention should be applicable to the claim regardless of whether the cause of action was based in tort or breach of contract, and that the plaintiffs' rights to damages had therefore extinguished because of the time limitation as set forth in Article 29(1) of the Convention. The difficult and often debated question of what exactly is meant by the words 'such default equivalent to wilful misconduct' in Article 25(1) of the Warsaw Convention, has also been litigated. The Supreme Court of Japan dealt with this issue in the Suzuki Shinjuten Co. v. Northwest Airlines Inc. case. The Supreme Court upheld the Appellate Court's ruling, and decided that 'such default equivalent to wilful misconduct' under Article 25(1) of the Convention was within the meaning of 'gross negligence' under the Japanese Commercial Code. The issue of the convention of the 'franc' into national currencies as provided in Article 22 of the Warsaw Convention as amended by the Hague Protocol has been raised in a court case in Korea, which is now before the District Court of Seoul. In this case, the plaintiff argues that the gold franc equivalent must be converted in Korean Won in accordance with the free market price of gold in Korea, as Korea has not enacted any law, order or regulation prescribing the proper method of calculating the equivalent in its national currency. while it is unclear if the court will accept this position, the last official price of gold of the United States as in the famous Franklin Mint case, Special Drawing Right(SDR) or the current French franc, Korean Air Lines has argued in favor of the last official price of gold of the United States by which the air lines converted such francs into us Dollars in their General Conditions of Carriage. It is my understanding that in India, an appellate court adopted the free market price valuation. There is a report as well saying that if a lawsuit concerning this issue were brought in Pakistan, the free market cost of gold would be applied there too. Speaking specifically about the future of the Warsaw System in Asia though I have been informed that Thailand is actively considering acceding to the Warsaw Convention, the attitudes of most Asian countries' governments towards the Warsaw System are still wnot ell known. There is little evidence that Asian countries are moving to deal concretely with the conversion of the franc into their own local currencies. So too it cannot be said that they are on the move to adhere to the Montreal Additional Protocols Nos. 3 & 4 which attempt to basically solve many of the current problems with the Warsaw System, by adopting the SDR as the unit of currency, by establishing the carrier's absolute liability and an unbreakable limit and by increasing the carrier's passenger limit of liability to SDR 100,000, as well as permiting the domestic introduction of supplemental compensation. To summarize my own sentiments regarding the future, I would say that given the fact that Asian air lines are now world leaders both in overall size and rate of growth, and the fact that both Asian individuals and governments are becoming more and more reliant on the global civil aviation networks as their economies become ever stronger, I am hopeful that Asian nations will henceforth play a bigger role in ensuring the orderly and hasty development of a workable unified system of rules governing international commercial air carriage.

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A study on Development Process of Fish Aquaculture in Japan - Case by Seabream Aquaculture - (일본 어류 양식업의 발전과정과 산지교체에 관한 연구 : 참돔양식업을 사례로)

  • 송정헌
    • The Journal of Fisheries Business Administration
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    • v.34 no.2
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    • pp.75-90
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    • 2003
  • When we think of fundamental problems of the aquaculture industry, there are several strict conditions, and consequently the aquaculture industry is forced to change. Fish aquaculture has a structural supply surplus in production, aggravation of fishing grounds, stagnant low price due to recent recession, and drastic change of distribution circumstances. It is requested for us to initiate discussion on such issue as “how fish aquaculture establishes its status in the coastal fishery\ulcorner, will fish aquaculture grow in the future\ulcorner, and if so “how it will be restructured\ulcorner” The above issues can be observed in the mariculture of yellow tail, sea scallop and eel. But there have not been studied concerning seabream even though the production is over 30% of the total production of fish aquaculture in resent and it occupied an important status in the fish aquaculture. The objectives of this study is to forecast the future movement of sea bream aquaculture. The first goal of the study is to contribute to managerial and economic studies on the aquaculture industry. The second goal is to identify the factors influencing the competition between production areas and to identify the mechanisms involved. This study will examine the competitive power in individual producing area, its behavior, and its compulsory factors based on case study. Producing areas will be categorized according to following parameters : distance to market and availability of transportation, natural environment, the time of formation of producing areas (leaderㆍfollower), major production items, scale of business and producing areas, degree of organization in production and sales. As a factor in shaping the production area of sea bream aquaculture, natural conditions especially the water temperature is very important. Sea bream shows more active feeding and faster growth in areas located where the water temperature does not go below 13∼14$^{\circ}C$ during the winter. Also fish aquaculture is constrained by the transporting distance. Aquacultured yellowtail is a mass-produced and a mass-distributed item. It is sold a unit of cage and transported by ship. On the other hand, sea bream is sold in small amount in markets and transported by truck; so, the transportation cost is higher than yellow tail. Aquacultured sea bream has different product characteristics due to transport distance. We need to study live fish and fresh fish markets separately. Live fish was the original product form of aquacultured sea bream. Transportation of live fish has more constraints than the transportation of fresh fish. Death rate and distance are highly correlated. In addition, loading capacity of live fish is less than fresh fish. In the case of a 10 ton truck, live fish can only be loaded up to 1.5 tons. But, fresh fish which can be placed in a box can be loaded up to 5 to 6 tons. Because of this characteristics, live fish requires closer location to consumption area than fresh fish. In the consumption markets, the size of fresh fish is mainly 0.8 to 2kg.Live fish usually goes through auction, and quality is graded. Main purchaser comes from many small-sized restaurants, so a relatively small farmer and distributer can sell it. Aquacultured sea bream has been transacted as a fresh fish in GMS ,since 1993 when the price plummeted. Economies of scale works in case of fresh fish. The characteristics of fresh fish is as follows : As a large scale demander, General Merchandise Stores are the main purchasers of sea bream and the size of the fish is around 1.3kg. It mainly goes through negotiation. Aquacultured sea bream has been established as a representative food in General Merchandise Stores. GMS require stable and mass supply, consistent size, and low price. And Distribution of fresh fish is undertook by the large scale distributers, which can satisfy requirements of GMS. The market share in Tokyo Central Wholesale Market shows Mie Pref. is dominating in live fish. And Ehime Pref. is dominating in fresh fish. Ehime Pref. showed remarkable growth in 1990s. At present, the dealings of live fish is decreasing. However, the dealings of fresh fish is increasing in Tokyo Central Wholesale Market. The price of live fish is decreasing more than one of fresh fish. Even though Ehime Pref. has an ideal natural environment for sea bream aquaculture, its entry into sea bream aquaculture was late, because it was located at a further distance to consumers than the competing producing areas. However, Ehime Pref. became the number one producing areas through the sales of fresh fish in the 1990s. The production volume is almost 3 times the production volume of Mie Pref. which is the number two production area. More conversion from yellow tail aquaculture to sea bream aquaculture is taking place in Ehime Pref., because Kagosima Pref. has a better natural environment for yellow tail aquaculture. Transportation is worse than Mie Pref., but this region as a far-flung producing area makes up by increasing the business scale. Ehime Pref. increases the market share for fresh fish by creating demand from GMS. Ehime Pref. has developed market strategies such as a quick return at a small profit, a stable and mass supply and standardization in size. Ehime Pref. increases the market power by the capital of a large scale commission agent. Secondly Mie Pref. is close to markets and composed of small scale farmers. Mie Pref. switched to sea bream aquaculture early, because of the price decrease in aquacultured yellou tail and natural environmental problems. Mie Pref. had not changed until 1993 when the price of the sea bream plummeted. Because it had better natural environment and transportation. Mie Pref. has a suitable water temperature range required for sea bream aquaculture. However, the price of live sea bream continued to decline due to excessive production and economic recession. As a consequence, small scale farmers are faced with a market price below the average production cost in 1993. In such kind of situation, the small-sized and inefficient manager in Mie Pref. was obliged to withdraw from sea bream aquaculture. Kumamoto Pref. is located further from market sites and has an unsuitable nature environmental condition required for sea bream aquaculture. Although Kumamoto Pref. is trying to convert to the puffer fish aquaculture which requires different rearing techniques, aquaculture technique for puffer fish is not established yet.

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