• Yonsei Medical Journal
• /
• v.59 no.9
• /
• pp.1049-1056
• /
• 2018

Purpose: Local recurrence is the most common cause of failure in retroperitoneal soft tissue sarcoma patients after surgical resection. Postoperative radiotherapy (PORT) is infrequently used due to its high complication risk. We investigated the efficacy of PORT using modern techniques in patients with retroperitoneal soft tissue sarcoma. Materials and Methods: Eighty patients, who underwent surgical resection for non-metastatic primary retroperitoneal soft tissue sarcoma at the Yonsei Cancer Center between 1994 and 2015, were retrospectively reviewed. Thirty-eight (47.5%) patients received PORT: three-dimensional conformal radiotherapy in 29 and intensity-modulated radiotherapy in nine patients. Local failure-free survival (LFFS), overall survival (OS), and RT-related toxicities were investigated. Results: Median follow-up was 37.1 months (range, 5.8-207.9). Treatment failure occurred in 47 (58.8%) patients including local recurrence in 33 (41.3%), distant metastasis in eight (10%), and both occurred in six (7.5%) patients. The 2-year and 5-year LFFS rates were 63.9% and 47.9%, respectively. The 2-year and 5-year OS rates were 87.5% and 71.1%. The 5-year LFFS rate was significantly higher in PORT group than in no-PORT group (74.2% vs. 24.3%, p<0.001). In multivariate analysis, PORT was the only independent prognostic factor for LFFS. However, there was no significant correlation between RT dose and LFFS. OS showed no significant difference between the two groups. Grade ${\leq}2$ acute toxicities were observed in 63% of patients, but no acute toxicity ${\geq}$ grade 3 was observed. Conclusion: PORT using modern technique markedly reduced local recurrence in retroperitoneal sarcoma patients, with low toxicity. The optimal RT technique, in terms of RT dose and target volume, should be further investigated.

• Journal of Korea Port Economic Association
• /
• v.24 no.1
• /
• pp.41-60
• /
• 2008

Korea has been doing a two-port system as a main port development policy and developing the port of Busan and Gwangyang as the transshipment hubs in the northeast Asia. However, the growth rate of the transshipment container volume of the Gwangyang port in 2007 was sharply dropping more than 31.4%. The reasons why reduced the growth rate of transshipment cargo were from the port development in north China and the direct callings of ships. Therefore, it is time to evaluate the transshipment hub port policy of Korea. This study would recognize the decision criteria of shipping companies as customers for the transshipment hub in the northeast Asia by the AHP methodology based on Lirn et al. (2004). It has been known the costs of shipping companies and port location as the main first tier criteria for transshipment ports, and container handling charges, closeness to the main navigation route, carriers' strategy, and nearness to the feeder ports as the important second tier factors. Finally, the domestic terminal operating companies would focus on only a few attributes including the terminal cost factor, but the international shipping companies would be considering more several factors than they do. Therefore, the transshipment port strategy should be enriched in the near future.

• Journal of Power Electronics
• /
• v.13 no.4
• /
• pp.558-568
• /
• 2013

In this paper, a new decoupling technique for a flyback inverter using an active power decoupling circuit with auxiliary winding and a novel switching pattern is proposed. The conventional passive power decoupling method is applied to control Maximum Power Point Tracking (MPPT) efficiently by attenuating double frequency power pulsation on the photovoltaic (PV) side. In this case, decoupling capacitor for a flyback inverter is essentially required large electrolytic capacitor of milli-farads. However using the electrolytic capacitor have problems of bulky size and short life-span. Because this electrolytic capacitor is strongly concerned with the life-span of an AC module system, an active power decoupling circuit to minimize input capacitance is needed. In the proposed topology, auxiliary winding defined as a Ripple port will partially cover difference between a PV power and an AC Power. Since input capacitor and auxiliary capacitor is reduced by Ripple port, it can be replaced by a film capacitor. To perform the operation of charging/discharging decoupling capacitor $C_x$, a novel switching sequence is also proposed. The proposed topology is verified by design analysis, simulation and experimental results.

• Transactions of the Korean Society of Automotive Engineers
• /
• v.11 no.2
• /
• pp.8-15
• /
• 2003

During cold operation, fuel injection in the intake port directly contributes to the unburned hydrocarbon formation in spark ignition engines. The relationship between injection parameters and HC emission behavior was investigated through a series of experiments. Spray behavior of port fuel injectors was characterized through a quantitative evaluation of mass concentration of liquid fuel by a patternator and PDA(Phase-Doppler. Anemometer). A 6-hole injector was found to produce finer spray than single hole injector. Using a purpose-built wall, the wetted fuel was measured, which was mostly affected by wall temperature. HC emissions were measured in a production engine varying coolant temperature$(20~80^{\circ}C)$, also with respect to the different types of injectors. In the 6-hole injector application, the engine produced less HC emission in low coolant temperature region. Though it produces much more amount of wetting fuel, it has the advantages of finer atomization quality. In high coolant temperature region, there was little effect by different types of injectors. The control schemes to reduce HC emissions during cold start could be suggested from the findings that the amount of fuel supply and HC emission could be reduced by utilizing fine spray and high intake wall temperature.

• The Journal of Information Technology
• /
• v.8 no.3
• /
• pp.143-158
• /
• 2005

The purpose of the paper is to analyze situations and its prospect of Single Window System for custom's one-stop service in Japan and to suggest effective application was to improve of in Korea's Customs systems. In response to the growing demand for lower trading costs and shorter and more predictable lead times with the advancement of the international trade supply chain, the Single Window System for import/export and port-related procedures was launched on 23 July 2003 in Japan. The concept of the Single Window System is to establish a comprehensive computer interface system that enables users to complete all import/export and port-related procedures required under different laws and regulations in a single input and single transmission. To realize the concept, the data elements and submission times of the various systems were harmonized, and manual procedures, such as quarantine and immigration, were computerized. Then, all the necessary systems, such as NACCS, Port EDI System, and Crew Landing Permit Support System, were interconnected as a Single Window System. Close cooperation among other governmental organizations and the private sector was a key factor in the successful development and smooth utilization of the System so that it fully met all parties' needs. It is anticipated that operating costs will be greatly reduced and trade facilitation will be enhanced as a result of the simplification of procedures. Korea Customs advocates the Single Window System as a best practice at ASEAN and WCO to contribute to the development of regional and international capacity building.

• Journal of the Korean Society of Mechanical Technology
• /
• v.13 no.2
• /
• pp.79-84
• /
• 2011

In general, a valve body of the automatic transmission(AT) is controlled by the clutch, the brake and lubricating oil flow in a hydraulic system and lubricant flow for each valve can be adjusted independently. To increase the lifetime of AT, the lubrication flow rate in a valve body for a 6 speed AT based parallel hybrid electric vehicle must be provided with proper oil distribution and control. In this study, we carried out several experiments without the inner parts of AT and with a AT assembly. The variation of the flow rate on oil temperature and pressure between an oil supply port and the outlets of the lubrication port was evaluated and analyzed. In the case of AT without the inner parts, it was evident that as the oil required for an operation of the clutch and brake was discharged from the outlet port, the flow rate from each lubrication port is decreased. However, the flow rate of the AT assembly was slightly increased. In addition, the lubrication flow rate was increased with increasing the oil temperature, and also it was reduced with increasing the oil pressure. Details of the resulting data are discussed.

• The Journal of Fisheries Business Administration
• /
• v.53 no.1
• /
• pp.73-84
• /
• 2022

The purpose of this study is the impact of national fishing port investment and typhoons on fisheries disaster damage. The dependent variables were the amount of damage to fishing ports, fishing boats, fisheries enhancement, external facilities, mooring facilities, functional facilities, fishing port and typhoons. The analysis period is from 2002 to 2018. Since the error term is in a simultaneous correlation, it was efficiently estimated by analyzing it with a seemingly unrelated regression (SUR) method. As a result of the analysis, external facilities have not significance to all models. Investing in mooring facilities increased the amount of damage to fishing ports for five years. Investing in functional facilities reduced the amount of damage to fishing ports and aquaculture over five years. Typhoons have significance to all models, and the amount of damage increased every time a typhoon occurred. Based on these results, as the influence of typhoons increases, it seems necessary to establish preventive measures. Timely investment and maintenance to enable the role and function of national fishing ports are considered important.

• Journal of Navigation and Port Research
• /
• v.40 no.3
• /
• pp.121-128
• /
• 2016

The present study aimed to derive decision factors for residency in the hinterland of Incheon New Port that is undergoing the development of port hinterlands and changes in leasing methods considered from the perspective of companies and analyze the priorities of determinants for residency through Fuzzy-AHP in order to present a direction to activate companies entries into the hinterland of Incheon New Port. When the comprehensive rankings of determinants for residency in the hinterland of Incheon New Port, rent levels among cost factors took the highest ranking with a value of 10.2% followed by the throughput of the port among market factors with a value of 8.2%, the scale of the market on the background with a value of 7.3%,, reduction in inland transport costs among cost factors with a value of 7.1%, connectivity to inland transportation networks among locational factors with a value of 6.7%, and designation as a free trade zone and the scale with a value of 6.4%. When seen from the viewpoint of companies to determine whether to move into the hinterland of Incheon New Port, the rent level should be provided to be more attractive compared to the hinterlands of ports in other regions. In addition, inland transportation costs which are a matter of the most serious concern of shippers in the capital region should be reduced and sea routes that can directly connect Incheon New Port to US ports and European ports should be opened.

• Journal of Korean Port Research
• /
• v.2 no.1
• /
• pp.29-73
• /
• 1988

Since the middle of 1950's when sea transportation service by container ship was established, containerization has been rapidly spread over the world with realization of intermodalism, and becomes an index of economy growth of a country. Our country has established Pusan Container Terminal at Pusan harbour in 1978 in step with worldwide trend of containerization, and is constructing New Container Terminal at Pusan outharbour which will be completed in 1990. This paper aims to make a quantitative analysis of the Pusan Container Terminal system through the computer simulation, especially focusing on its subsystems such as ship stevedoring system, storage system and transfer system. First, the capacity of various subsystems are evaluated and it is checked whether the current operation is being performed effectively through the computer simulation. Secondly, the suggestion is presented to improve the operation by considering the throughput that Pusan Container Terminal will have to accept until 1990, when New Container Terminal will be completed. The results are as follows ; 1) As the inefficiency is due to the imbalance between various subsystems at Pusan Container Terminal on the basis of about 1.2 million TEU of container traffic, transfer equipment level must be up to 33% for transfer crane, and free period must be reduced into 4/5 days for export/import. 2) On the basis of about 1.4 million TEU of container traffic, transfer equipment level must be up to $12\%$ for gantry crane, $11\%$ for straddle carrier and $66\%$ for transfer crane, and free period must be reduced into 3/4 days for export/import. 3) On the basis of about 1.7 million TEU of container traffic, transfer equipment level must be up to $25\%$ for gantry crane, $28\%$ for straddle carrier and $100\%$ for transfer crane, and free period must be reduced into 3/4 days for export/import. 4) On the basis of about 2 million TEU of container traffic, transfer equipment level must be up to $25\%$ for gantry crane, $30\%$ for straddle carrier and $110\%$ for transfer crane, and free period must be reduced into 2/3 days for export/import, and it is necessary to enlarge storage yard.

• Journal of Navigation and Port Research
• /
• v.31 no.10
• /
• pp.853-858
• /
• 2007

In this paper, a seesaw system composed with a moving cart on the rail and seesaw frame is made to demonstrate the effectiveness of the control theory. The control aim is to maintain an equilibrium of seesaw frame in spite of various initial conditions and an allowable disturbance. To solve this control problem, a PI-type state feedback controller using reduced-order observer is implemented and applied to the seesaw system. The reduced-order observer can be used to estimate the state variables in the case of the limit of sensor number or the constraint on setting sensors and the cost. A series of simulation are carried out to verify the effectiveness of the control system.