• Journal of Drive and Control
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• v.10 no.1
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• pp.7-13
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• 2013

Port size 80mm or above large-flow type solenoid valves are extensively used in dust collector and power plants. These multi-stage solenoid valve have few problem. first, multi-solenoid valves are almost depend on imports and there are weak in the brine environment and the low energy efficiency. Because these problem, increased the necessity of research on the development of large flow and high pressure type solenoid valves. In this study, describe the design method of multi-stage solenoid test bench and confirm the influence valve performance on several parameter such as diaphragm orifice diameter. At first, each part has modeled by AMESim simulation tool and combining them. This AMESim virtual multi-stage solenoid valve found influence valve performance on the valve parameter. Finally developed the multi-stage solenoid valve and verified that performance on experimental result.

• Journal of the Korean Society of Marine Environment & Safety
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• v.18 no.4
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• pp.316-322
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• 2012

In the port of Ulsan with the area of harbor limit of $83km^2$, 25,432 vessels have been entering annually and only 35 vessels can anchor simultaneously at the anchorage. The area of harbor limit of Ulsan constitutes just 65 percent compared to $127.5km^2$ which is an average of main ports in Korea. In this regard, the port of Ulsan needs to expand the area of anchorages inevitably for enhancing the efficiency of port operation. To select the best anchorage area in Mipo harbor with the introduction of a concept of emergency anchorage, this study analyzed the safety of navigation and anchorage, and safety management, etc. in the prospected anchorage on the basis of the marine traffic survey observing traffic density. Furthermore, after drawing preliminary and final schemes through gathering the opinions from maritime users, safety management organizations and academic experts group, the best arrangement of emergency anchorage has been selected through the conference of interested parties. Then, the final scheme was also verified through figuring out the marine traffic system and carrying out the ship handling simulation.

• Annual Conference of KIPS
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• 2002.04a
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• pp.273-276
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• 2002

본 논문에서는 Physical Modeling을 이용해 단소의 음을 합성해 내는 방법에 대해 연구 하였다. 현재 관 악기의 음 합성 방법은, Julius O. Smith가 제안한 digital waveguide모델을 근간으로 하여 여러 악기들의 소리를 합성하는 방법에 대해 연구 되고 있다. 본 논문에서는 digital waveguide모델을 사용하여 단소 관속의 움직임, two-port scattering model을 이용한 관속과 음공 사이의 공기의 움직임에 대해 기술하였고, reflection filter를 사용하여 단소 끝부분에서의 신호의 변화에 대해 연구 하였으며, 끝으로 관 내벽과 공기의 마찰에 의한 신호 손실에 대한 연구를 기술 하였다. 위에서 언급한 내용들의 연구결과를 토대로 음을 합성한 결과 실제 단소의 소리와 유사한 소리를 얻어 낼 수 있었다.

• Journal of the Korean Society of Marine Environment & Safety
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• v.5 no.2
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• pp.1-14
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• 1999

To find characteristics and areas of greater risk of oil spill at the coastal waters in Korea, some of risk factors were analyzed with historical data of oil spill and marine traffic. As a result, it is characterized that frequency of oil spill is increasing year by year and greatest percentage of spill source is fishing boat. It is proposed that the ports of Ulsan, Yeosu, Incheon and Pusan will be designated as primary area of risk as they have a higher risk of oil spills and its response authority is required to maintain appropriate regional response capability for prompt and effective response to a future spill incident. In addition, the regional response equipments at Ulsan are examined under a assumption of a medium size spill and it is found that the use of chemical dispersant can be an alternative when mechanical containment and recovery is not feasible in this area, and the existing response equipments may be appropriate to address that size of spill. However, the response authority is required to maintain more numbers of stronger boom for unsheltered waters and more quantity of concentrate dispersant to disperse all spilled oils on the water, furthermore the response authority should be prepared for a possible future catastrophic spill with sufficient equipments.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2017.11a
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• pp.32-33
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• 2017

As the era of e-navigation begins, the significance of harmonized collection, exchange, and integration of marine information conventional "ship-to-ship" and "ship-to-shore"/"shore-to-ship" has become more significant in ensuring safety and security at sea. This research aims to provide an internationally applicable list of Standard e-Navigation Phrases (SENP ) for communication in the e-Navigation environment, along with practical approaches to this. For this purpose, the importance of standardized communication phrases specific to e-Navigation will first be illustrated. In order to approach the e-Navigation phrases in a practical and pragmatic manner, means of compiling and processing authentic VHF linguistic data accumulated from one of the Korean ports, Ulsan, will be detailed. In addition, major outcomes to be considered in designing SENP will be suggested. Finally, future actions and a joint effort for the standardization of e-Navigation phrases among stakeholders will be sought.

• Journal of Environmental Science International
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• v.19 no.12
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• pp.1447-1454
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• 2010

In this study, the detection limits of lower fatty acids in air were investigated by using Dynamic SPME(Solid Phase Micro-Extraction), i.e. improved Head Space - SPME method(HS-SPME). This Dynamic SPME, called SPDE(Solid Phase Dynamic Extraction), is the analytical method for volatile compounds in air with the extraction by using a stainless steel needle of which inner surface is coated with adsorption material and following the gas chromatographic analysis by inserting the needle into a injection port of GC and subsequently, desorption of the volatile compounds into a gas-chromatographic column. Extraction was carried out by passing the sample air through the needle with a suction pump which has been used for a detection tube. The result of measurement for the 6 lower fatty acids showed that the detection limits ranged from 0.10 ppm to 0.44 ppm and the linear correlation coefficients were over 0.99. Relative standard deviations obtained from 5 analytical repetition of a ca. 1.6 ppm standard mixture were in the range of 1.87%~2.47%. This method has been shown to be a adequate for the measuring C2~C5 fatty acids in air in the concentrations of over several hundreds ppb.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2017.11a
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• pp.190-192
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• 2017

The manufacture of current Loran-C signal receiver has been discontinued and there are no spare parts for that. eLoran system is being developed. Judging from these facts, it is necessary to purchase eLoran receivers which also can receive Loran-C signal. Furthermore, the coverage of Loran-C has been decreased as the closure of transmitting stations in Japan. The current monitor station in Ganjeolgot, Ulsan shall be moved to a new place.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2018.05a
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• pp.206-208
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• 2018

울산신항의 활발한 개발로 인하여 기존에 설치되어 있던 온산항북방파제는 원래의 목적인 방파제로서의 기능은 사라지고, 울산항 3항로에 간섭된 지장물이 됨에 따라, 기존방파제의 철거를 수행하였으며 철거순서는 상치 콘크리트 깨기, 속채움 제거, 케이슨 절단 및 천공, 인양 및 제거, 케이슨 파쇄의 순서로 진행되었다. 특히, 파쇄한 콘크리트는 크라싱 작업을 통해 재생골재로 생산하였으며, 향후 신설케이슨의 속채움 재료로 재활용하는 것으로 하여 경제적 자원재활용에도 기여하고 있다.

• Journal of Fisheries and Marine Sciences Education
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• v.19 no.2
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• pp.278-287
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• 2007

Since traffic congestion ratio at any given port fluctuates on the number of arriving and departing vessels, the total tonnage of freight volume being handled, and the number of berth in operation and other factors, there exists a need to numerically analyze the waterway traffic volume. However, there are no effective regulations in regards to the waterway traffic analysis prior to expansion of a port facility. The current analysis requires the traffic analysis in relation only to the width of the waterway, which clearly falls short of achieving a comprehensive evaluation study that could be used in consideration of port expansion.This study provides five scenarios to execute a comprehensive evaluation study and base for the sensitivity study by analyzing the scenarios. As a result of the sensitivity analysis, the A, B, and C scenarios varies the average arrival ratio of the berth shows 1.1, 1.19, and 1.28 times of delays respectively. Also, The D and E scenarios take place malfunctions of pier shows 1.21 and 1.53 times of delays respectively. Therefore, various strategies of harbor development and method of harbor management are needed for the flexible correspondence to the environmental changes such as the excessive increasing of the freight volume and often taking place of malfunctioning.

• Transactions of the Korean Society of Automotive Engineers
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• v.19 no.5
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• pp.29-34
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• 2011

This study investigates the potential of DME/Diesel dual fuel engine for reducing emissions with same power. Dual fuel engine controls the combustion using two different fuels, DME and diesel with different auto-ignition timings. In the previous work, the caracteristics of combustion and emissions under single cylinder engine and ignition is done by compression ignition. Pre-mixture is formed by injecting low-pressure DME into an intake manifold and high-pressure fuel (diesel or DME) is injected directly into the cylinder. Both direct diesel injection and port fuel injection reduced the significant amount of Smoke, CO and NOx in the homogeneous charge compression ignition engine due to present of oxygen in DME. In addition, when injecting DME directly in cylinder with port DME injection, there is no changes in emissions and energy consumption rate even operated by homogeneous charge compression ignition.