• 생체재료학회지
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• 제22권4호
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• pp.290-302
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• 2018

Background: The main purpose of drug delivery systems is to deliver the drugs at the appropriate concentration to the precise target site. Recently, the application of a thin film in the field of drug delivery has gained increasing interest because of its ability to safely load drugs and to release the drug in a controlled manner, which improves drug efficacy. Drug loading by the thin film can be done in various ways, depending on type of the drug, the area of exposure, and the purpose of drug delivery. Main text: This review summarizes the various methods used for preparing thin films with drugs via Layer-by-layer (LbL) assembly. Furthermore, additional functionalities of thin films using surface modification in drug delivery are briefly discussed. There are three types of methods for preparing a drug-carrying multilayered film using LbL assembly. First methods include approaches for direct loading of the drug into the pre-fabricated multilayer film. Second methods are preparing thin films using drugs as building blocks. Thirdly, the drugs are incorporated in the cargo so that the cargo itself can be used as the materials of the film. Conclusion: The appropriate designs of the drug-loaded film were produced in consideration of the release amounts and site of the desired drug. Furthermore, additional surface modification using the LbL technique enabled the preparation of effective drug delivery carriers with improved targeting effect. Therefore, the multilayer thin films fabricated by the LbL technique are a promising candidate for an ideal drug delivery system and the development possibilities of this technology are infinite.

• 한국산림과학회지
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• 제85권3호
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• pp.513-523
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• 1996

본 연구는 임도의 노선 선형이 차량의 주행속도에 마치는 영향을 규명하고, 임도의 구조를 개선할 수 있는 개선책을 제시하고자 하였다. 이러한 목적을 달성하기 위하여 본 연구는 기존의 임도 설계서 및 설계도면을 검토사여 연구 목적에 부합하는 임도를 선정하고, 연구대상 임도에 대해 종단물매, 노폭, 곡선반지름, 곡선길이, 곡선부의 편구배 등 노선선형 인자와 노면의 상태 등을 측정하였다. 선택된 실험차량을 이용하여 주행실험을 한 결과, 차량의 주행속도에 크게 영향을 미치는 인자는 노면의 상태, 곡선반지름, 학성물매, 곡선길이, 종단물매인 것으로 나타났다. 또한, 실험차량의 주행속도는 임도시설규정에서 제시된 설계속도에 비해 낮은 값을 나타내었으며, 적재시(적차)의 주행 속도는 비적재시(공차)에 비해 70-85%의 값을 보였다. 그리고 노면의 상태에 따라 곡선반지름과 종단물매의 증가에 따른 주행속도의 변화를 식으로 나타낼 수 있었다. 이러한 연구의 결과는 가존의 임도 뿐만 아니라 향후 개설될 임도의 질을 판단하고, 임도에서의 주행속도를 개선시킬 수 있는 임도 구조의 선택을 가능하게 할 것으로 생각된다.

• 대한안전경영과학회지
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• 제10권2호
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• pp.95-103
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• 2008

The package loading process of the lumbering industry is an operation that after a pair of workers bind three or six lumbers into one unit and cut both ends of the lumbers, transports the weight cargo of 30-50kg by one meter, pack and load at a height of 1.2 meters. This package loading process causes lots of noise and wood dust when workers carry out the heavy work as the above. Therefore we developed the monolithic both ends cutting package loading equipment in order to prevent from getting musculoskeletal disease. An loading bar working system of this equipment is improved from pneumatic pressure system to oil pressure system, furnished the newly designed flow dividers, and developed the new system that a both end array is loaded identically. Also we developed the safety equipment of loading bar in order to prevent workers mistake and overload from malfunction during the package loading process. The main cause of job evasion on working place could be solved by preventing the musculoskeletal disease and improving the working environments.

• 한국항해항만학회:학술대회논문집
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• 한국항해항만학회 2014년도 춘계학술대회
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• pp.46-48
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• 2014

인천항은 지리 위치적인 특성으로 인하여 조류가 강하고, 가항수역이 협소할 뿐만 아니라 굴곡이 심하여 지금까지 인천항 입출항 최대크기의 선박은 7만 DWT급의 만재상태의 파나막스 정도만 가능했으나, 앞으로는 반재(Half loading)한 상태의 VLCC가 입출항할 것으로 판단된다. 따라서 인천항 입항항로인 동수도 항로 주변여건을 다각도로 검토하고, VLCC의 조종특성을 감안한 입출항 안정성을 선박조종 시뮬레이션을 통하여 평가하였다.

• 대한안전경영과학회:학술대회논문집
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• 대한안전경영과학회 2008년도 춘계학술대회
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• pp.135-147
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• 2008

The package loading process of the lumbering industry is an operation that after a pair of workers bind three or six lumbers into one unit and cut both ends of the lumbers, transports the weight cargo of 30-50kg by one meter, pack and load at a height of 1.2 meters. This package loading process causes lots of noise and wood dust when workers carry out the heavy work as the above. Therefore we developed the monolithic both ends cutting package loading equipment in order to prevent from getting musculoskeletal disease. An loading bar working system of this equipment is improved from pneumatic pressure system to oil pressure system, furnished the newly designed flow dividers, and developed the new system that a both end array is loaded identically. Also we developed the safety equipment of loading bar in order to prevent workers mistake and overload from malfunction during the package loading process. The main cause of job evasion on working place could be solved by preventing the musculoskeletal disease and improving the working environments.

• 드라이브 ㆍ 컨트롤
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• 제18권1호
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• pp.9-16
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• 2021

Overloaded vehicles increase the maintenance cost of road structures, and they are a major factor in causing damage to the roads and bridges. In addition, overloaded vehicles compromise the braking capability of the vehicle; thus, threatening the safety of the driver. In order to prevent overloading of vehicles, the government is cracking down on the roads by using a device that measures the weight of vehicles. But this process is inconvenient because the place where the equipment is installed is far away from where the cargo is loaded. Due to the limitations of these fixed weighing devices, there is a growing need for technology that can monitor vehicle weight distribution and overload conditions in real time. In this work, we develop an onboard scale that can measure the load (weight) of trucks in real time. The onboard scale consists of high sensors, a signal processing unit, and a display, and it measures the load using height-displacement of the vehicle's leaf spring suspension.

• 한국기계가공학회지
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• 제20권3호
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• pp.53-59
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• 2021

In vibration-free vehicles such as limousine buses, the vibration is minimized by installing an air spring instead of the leaf spring used in the existing freight cars to prevent the damage to the loaded cargo from shocks generated during movement. In the existing vehicles, steel structures support the air spring system. This study was aimed at replacing the steel structures used in the Z-spring by carbon fiber and glass fiber reinforced plastics. In addition, the mechanical properties (elastic modulus, tensile strength, and shear strength) of carbon fiber and glass fiber prepreg were derived using specimens molded with the corresponding prepreg. The final goal was to develop a material lighter than the conventional steel material but with enhanced mechanical properties. Although the CF prepreg exhibited excellent mechanical properties, the production cost was extremely high. To overcome this limitation, hybrid composites with GF prepreg were examined, which are expected to be promising future materials.

• 해양환경안전학회지
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• 제26권6호
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• pp.587-593
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• 2020

국내 연안의 카페리선박의 고박안전성은 화물의 중량과 적재된 위치에서 발생할 수 있는 선체가속도를 기반으로 한 작용 외력과 고박장치의 고박력 비교를 통해 평가하고 있다. 고박안전성 평가에 기본이 되는 국내 기준상의 선체가속도는 선박의 특성 및 항해조건의 반영이 없이 적용되고 있다. 본 연구에서는 국내 연안 카페리선박의 선체가속도를 분석하고자 부산-제주를 통항하는 DWT 6,800톤급 선속 15.5 knots의 선박을 기준으로 선체의 4개 지점에서 총 12회의 가속도 계측을 수행하였고, 항해구역 인근 기상관측 부이의 데이터를 수집하였다. 한정된 계측 결과에 대한 이론적 비교 분석을 위하여 수치 시뮬레이션을 통하여 주파수 응답 해석을 통한 RAO를 해석하였고, RAO 결과를 바탕으로 4개 지점에 대한 가속도 해석을 수행하였다. 가속도 비교 결과 위치별 정도의 차이는 있으나 Y축 가속도의 경우 해석 1.81 m/s², 계측 1.47 m/s²로 해석 시뮬레이션 결과가 0.34 m/s² 높게 분석되었고, 고박안전성 평가기준 8.59m/s²와 비교해 볼 때 해석은 22 % 수준, 계측은 18 % 수준으로 분석되었다.

• 해양환경안전학회지
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• 제23권5호
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• pp.439-446
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• 2017

해사안전법에서는 기름 1,500킬로리터 이상 또는 유해액체물질 1,500톤 이상을 싣고 운반하는 유조선에 대하여 통항을 금지하는 유조선통항금지해역을 설정하고 있다. 이러한 선박이 유조선통항금지해역 내에 위치한 항만에 입출항하는 경우 유조선통항금지해역 바깥쪽 해역에서부터 항구까지의 거리가 가장 가까운 항로를 이용하여 입출항하도록 허용된다. 이는 유조선이 유조선통항금지해역에서 항행하는 시간이나 거리를 최소화하기 위한 것으로, 연안통항대를 이용한다는 의미로 해석되어서는 아니된다. 본 연구에서는 여수 광양항 특정해역 진입수로를 이용하지 않는 연안유조선의 교통량을 분석하고, 선박의 선적화물량을 조사하였다. 조사기간 중 연안통항대를 이용하는 총 31척의 연안유조선 중 51.6 %에 해당하는 16척의 선박은 1,500톤 이상의 화물을 적재한 것으로 나타났다. 이는 유조선통항금지해역의 입법취지에 타당하지 않는 것으로, 본 연구에서는 유조선통항금지해역의 바깥쪽 해역으로부터 특정해역 진입수로까지를 연결하는 해역을 설정하여 여수 광양항 유조선 입출항 항법 규정(안)을 제시하였다.

• 한국항해학회지
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• 제10권2호
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• pp.31-55
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• 1986

Generally, the development of shipping is characterized by the amount of traffic flow (traffic volume) and seaborne cargo in the sea. Movement of ships is an essential element of constructing the traffic flow which is represented the dynamic movement of ships in the sea, but on the other band the numbers of arriving and departing the port is the basic factor consisting of the static movement of ships. The amount of cargoes by coastal vessels and ocean trade vessels have increased tremendously with the great growth of the Korean economy these days. This increase of the seaborne cargoes has made the Korean coastal traffic flow so congested that this can be a cause of large pollution as well as great marine casualities such as a loss of human lives and properties . And also the future coastal traffic is expected to increase considerably according to our economic development and high dependence upon foreign trade. Under the circumstance, to devise the safety of coastal traffic flow and to take a proper step of a efficient navigation, there is a necessity for analyzing and surveying the coastal traffic trend and the characteristics of cargo movement. In order to grasp the dynamic movement of ships in the Korean coast, O/D analysis is executed. This paper aims to secure the basic data necessary for a comprehensive plan and estimation of vessel traffic management system for the enhancement of safety, order and efficiency of vessel traffic in the Korean coast. The analyzed results of the traffic flow and seaborne cargoes of the Korean coast are summarized as follows : 1) The congestion by the vessels occurred around the ports such as-in proportion of ship's number (proportion of tonnage) -Incheon 18.5%(14.8%), Pohang 5.9% (9.9%), Samil 5.2%(8.3%), Mokpo 8.6%(0.8%), Pusan 13.5%(36.4%), Ulsan 9.1%(16.2%). 2) It is found that the area adjacent to Incheon, Pusan, Ulsan, Channel of Hanryu and South-western area are heavily congested. 3) It is confirmed thatthe area adjacent to Incheon, Pusan, Ulsan, Channel of Hanryu and South-western area are heavily congested. 3) It is confirmed that the coastal vessels are main elements constituting the coastal traffic and that there are much traffic flow among five ports as following through the precise O/D analysis of ship's coastal movement. Incheon-Samil, Ulsan, Pusan, Jeju Pusan -Samil, Ulsan, Incheon, Jeju Pohang -Samil, Inchoen, Jeju Pohang -Samil, Incheon, Jeju Ulsan -Samil, Incheon, Jeju Samil -Ulsan, Pusan, Incheon 4) The amount of cargoes to abroad are in proportion about 81% of total and the amount of coastal cargoes are about 19%. Of those, cargoes in and out to Japan are about 26% and to South-east Asia are about 27%. 5) The chief items of foreign cargoes are oil(38.33%), iron ore(13.98%), bituminoous coal(12.74%), grain(8.02%), lumber(6.45%) in the import cargoes and steel material(21.96%), cement(17.16%), oil(6.81%), fertilizer(3.80%) in the export cargoes. 6) The 80.5% of total export cargoes and 92.4% of total import cargoes are flowed in five main ports. 7) The chief items of coastal cargoes are oil (42.45%), cement(16.86%), steel material (6.49%), anthracite(6.31%), mineral product(4.3%), grain, and fertilizer. Almost 92.24% of total import and export oil cargoes in Korea is loaded and unloaded at the port of Samil & Ulsan.