• Journal of Navigation and Port Research
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• v.33 no.1
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• pp.51-56
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• 2009

This paper presents the design of high sensitive/broadband tag antenna for Radio Frequency Identification (RFID) in Ultra High Frequency(UHF) band. A proposed tag antenna size is $60\;mm\;{\times}\;10\;mm\;{\times}\;1\;mm$. The resonant frequency is 910MHz and bandwidth is about 900 MHz at -10 dB below. The measured return loss and directional pattern have been confirmed a good agreement with the calculation results. The read range of proposed tag antenna with chip is observed about 6.5 m and proposed tag antenna has been observed an average 0.5 m for more than read range of the commercial tag antenna.

• Journal of Korean Society of Forest Science
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• v.97 no.4
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• pp.385-391
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• 2008

Republic of Korea (ROK) log import companies have clustered around In-cheon, Jeon-buk and Busan. This reason related to port for log import. This study analyzed the quantity of Whole imported log transported by port. As the result of analysis, In-cheon port accounted for 56.9% log import, which is the maximum log import port in ROK. Next Bu-san port 20.9%, Gun-san port 17.9%. However, these port have declined the quantity of imported log transported since 2000. Gun-san port and Dong-hae port increased narrow range. The reason of why In-cheon and Bu-san port declined log import and Gun-san and Dong-hae port increased is that a sudden rise in the price of log in 2003, and import of using a container ship increased. In the addition, log import from Far eastern Russia, Germany and America increased through a container ship, however, declined log import through a bulk ship. Most of imported log at In-cheon port are from New zealand and Russia, imported logs at Bu-san port are almost from US and New zealand.

• Journal of the Korean Society of Propulsion Engineers
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• v.20 no.6
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• pp.54-60
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• 2016

Multi-port HDPE and Paraffin firing tests are conducted for hybrid gas generator application of a ducted rocket in the low oxidizer mass flux range. A fuel rich gas of O/F ratio from 0.3 to 0.8, a typical O/F operating range of a ducted rocket gas generator, have been achieved with paraffin fuel implying that the hybrid system can be a potential candidate. It was also found that an almost constant O/F ratio regime exists under $35kg/m^2s$ of the oxidizer mass flux, opening a possibility for the paraffin fuel toward the VFDR gas generator application.

• Transactions of the Korean Society of Mechanical Engineers
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• v.16 no.7
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• pp.1408-1418
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• 1992

The valve timing and intake system in SI engine is chosen in order to get the maximum performance at the target rpm. This is a compromise and the performance reduction is expected in a certain rpm range. Therefore, to accomplish the possible engine capacity all over the operation ranges, it is required to investigate the effects of intake system and valve timing on engines more thoroughly. In this paper, it was attempted to examine closely the combined effects on the torque and the volumetric efficiency due to the change of valve timing and intake system dimensions. For this, the inlet port pressure was chosen as a primary parameter to represent engine performance characteristics together with surge tank pressure and induction pressure as secondaries. The inlet port pressure was analyzed in connection with both the secondaries and the performance data. Especially the relation between the inlet port pressure and the torque and volumetric efficiency was investigated on the operating conditions. In this experiment, it was acquired that the performances at specific rpm range could be improved by the combinations of valve timing and intake system. Then it was verified that pressure at a intake system contained useful data for the engine performance. By the analysis of inlet port pressure with the others, it was obtained that the properties of the torque and the volumetric efficiency due to the change of valve timing and intake conditions were able to be defined by the average and the maximum inlet port pressures, the pressure near before the intake valve closing(IVC) point as well as the pressure at IVC point during the intake valve opening duration. These results could be applied to almost all over the experimental conditions.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.21 no.6
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• pp.651-659
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• 2010

In this paper, a new six-port direct conversion receiver for high-speed multi-band multi-mode wireless communication system such as software defined radio(SDR) is proposed. The designed receiver is composed of two CMOS four-port BPSK receivers and a dual-band one-stage polyphase filter for quadrature LO signal generation. The four-port BPSK receiver, implemented in 0.18 ${\mu}m$ CMOS technology for the first time in microwave-band, is composed of two active combiners, an active balun, two power detector, and an analog decoder. The proposed polyphase filter adopt type-I architecture, one-stage for reduction of the local oscillator power loss, and LC resonance structure instead of using capacitor for dual-band operation. In order to extent the operation RF bandwidth of the proposed six-port receiver, we include I/Q phase and amplitude calibration scheme in the six-port junction and the power detector. The calibration range of the phase and amplitude mismatch in the proposed calibration scheme is 8 degree and 14 dB, respectively. The validity of the designed six-port receiver is successfully demonstrated by modulating M-QAM, and M-PSK signal with 40 Msps in the two-band of 900 MHz and 2.4 GHz.

• Journal of Navigation and Port Research
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• v.36 no.1
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• pp.43-49
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• 2012

Gwangyang port has aimed to establish and expand infrastructure since 2004 as a way of logistics industry development plan for activation of port and increase in traffic. However, it faces many changes due to reduced development of Gwangyang port, slowdown of traffic, and decrease in terminal operators. The need for review of plan and direction regarding infra is on the rise at this point for the purpose of ensuring the stable growth foothold of Gwangyang port and attaining independence of Port. This report focuses on the software infrastructure improvement alternative rather than hardware infrastructure. To analyze the priority of this alternative, AHP technique was applied as a research methodology. In this study, as a measure for decision-making, profitability, ease, urgency, and prospects have been selected, and alternatively, buildup of global networking, training of logistics professionals, operation of environment-friendly & low cost port, and development of specialized logistics companies have been selected. Survey has been conducted toward shipping companies which use Gwangyang port, port operators, hinterland logistics companies and consignor' logistics professionals. As a result of survey, the priorities of measuring range were shipping companies, port operators, consignor, and hinterland logistics companies. Meanwhile, the priorities of measuring elements were profitability, prospects, urgency and then ease. The priorities of alternatives were found to be a buildup of global networking, operation of environment-friendly & low cost port, development of specialized logistics companies and training of logistics professionals.

• Proceedings of the Korea Concrete Institute Conference
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• 2003.11a
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• pp.581-586
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• 2003

The objective of this study is to evaluate the injection performance of crack repair method in concrete structure. To improve the quality of the concrete structure caulking material was injected into the crack of building that were planned to be demolished and injection properties of various repair method were compared and assessed according to type of crack. Results from the test showed that when cracks and injection port were integrated and the injection port wasn't blocked repair material was able to be injected even below around 40㎏/㎠ pressure. Moreover, effective pressure each type of packer showed wide range varying from 200-400㎏/㎠. As for drill method for injection port, core drill method has shown to be more effective compared to the air pump method

• Yonsei Medical Journal
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• v.59 no.9
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• pp.1049-1056
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• 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
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• v.29 no.3
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• pp.159-174
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• 2013

This paper mainly deals with the appropriation of ship voyage allocation, using a heuristic regression model, in order to reduce total costs incurred in port, yard and at sea under the specific port condition. Because of different behavior of costs incurred in port, yard and at sea, an effort to minimize these costs by adjusting the number of voyages for three ship classes(50,000, 100,000, and 150,000-ton) should be made. For instance, if the port managers attempt to reduce the sea transport cost by increasing the annual allocated number of ship voyages classed 150,000-ton for economies of scale, they have no choice but to suffer a significant increase in queueing cost due to port congestion. To put it differently, there are trade-off relationships among the costs incurred in port, yard, and at sea. We utilized a computer simulation result to perform a couple of regression analyses in order to figure out the appropriate range of allocated number of voyages of each ship class using a heuristic approach. The detailed analytical results will be shown at the main paper. We also suggested a net present value(NPV) model to make a proper investment decision for an additional berth of 200,000-ton class that alleviates port congestion and reduces transport cost incurred both in port and at sea.

• Journal of the Korea institute for structural maintenance and inspection
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• v.27 no.6
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• pp.13-21
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• 2023

In this study, the coastal airborne chlorides were investigated in the Incheon Port, South Korea. Monthly measurements of coastal airborne chlorides were taken for a total of 2 years from September 2021 to August 2023 at 15 locations in North, South, and New Port. We analyzed the distribution characteristics of airborne chloride based on port facilities and measurement environments, as well as the reduction characteristics of the airborne chloride with respect to coastal distance. As a result, the monthly distribution range of the airborne chloride in the North, South, and New Port varied similarly, ranging from 0.4 to 3.3 mdd. Due to the influence of seasonal winds considering the direction of the coastline, both the North Port and South Port had higher the airborne chloride in winter, while the New Port had higher content in summer. The airborne chlorides were higher at locations inside an inland sea compared to those outside an inland sea. This is because the wind coming from the sea passed through the inland sea. Even in the same region with identical coastal distances, there were variations in airborne chloride levels depending on the height above the ground. In tidal zone, the monthly airborne chlorides were significantly higher in the lower part than in the upper part. The rate of decrease equation of airborne chlorides for each port based on the distance from the coastline was derived, and the results showed that as the distance from the coastline increased, the rate of decrease in airborne chlorides was the highest for New Port and the lowest for South Port.