• 선박안전기술공단연구보고서
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• s.4
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• pp.1-108
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• 2007

2007. 7. 23 IMO의 NAV(항해안전전문위원회)53차 회의에서는 e-Navigation을 해상에서의 안전, 보안, 해양환경보호를 목적으로 전자적인 수단에 의해 선박과 육상에서 해양정보를 수집, 교환, 표시함으로써 항구와 항구간의 항해 및 관련된 서비스를 향상시키는 것으로 정의하고 있다.2005년 11월 영국의 교통부 장관 Stephen 박사는 Royal Institute ofNavigation에서의 연설에서 해상안전과 환경보호를 위하여 선박의 항해를 감시하는 관제소 및 항행하는 선박에 유용하고 정확한 정보가 더 많이 필요함을 역설하였다. 그리고 첨단 기술에 의해 자동화된 항공 항법분야를 예로들면서, 선박의 항법 분야도 항해와 관련된 모든 시설 및 작업을 전자적 수단으로 대체하는 개념인 e-Navigation으로 전환되어야 하며 영국은 이에 필요한 작업을 주도하겠다는 의견을 피력하였다. Stephen은 e-Navigation 도입으로 얻을 수 있는 이익으로 첫째, 항해 실수로 인한 사고 확률저감, 둘째,사고 발생 시 인명 구조 및 피해 확산을 위한 효율적 대응, 셋째, 전통적인항해시설 설치 불필요로 인한 비용 저감, 넷째 선박입출항 수속의 간편화 및항로의 효율적 운용으로 인한 상업적 이익 등을 들었다. 반면에e-Navigation 체계로 전환 시 예상되는 장애로는 첫째, 체계 구축을 위한 비용(특히 개발도상국가들의 경우 어려움 예상), 둘째, e-Navigation의 성과 달성을 위하여 세계 전 해역의 모든 선박이 e-Navigation 체계에 동참하도록유도하는 문제, 셋째, 전자해도 표시 및 선교 장비들에 대한 표준화 문제, 넷째, 육상에 설치할 e-Navigation 센터의 설계 및 구축 등을 꼽았다.IMO는 2005년 81차 MSC(해사안전위원회) 회의에서 영국이 일본, 마샬아일랜드, 네덜란드, 노르웨이, 싱가포르, 미국과 공동으로 제안한 ‘e-Navigation전략 개발’ 의제를 2006년 82차 MSC 회의에서 채택하고, NAV(항해 전문위원회)를 통하여 2008년까지 e-Navigation의 구체적 개념을 정립하고 향후 개발하여야 할 전략적 비전과 정책을 수립하기로 하였다. 이어서 영국을 의장으로 e-Navigation 전략개발 통신작업반이 구성되었는데, 지난 년간 19개국, 16개 전문기관이 참여하여 아래의 작업이 수행되었다. ○ e-Navigation 개념의 정의와 목적 ○ e-Navigation에 대한 핵심 이슈 및 우선 순위 식별 ○ e-Navigation 개발에 따른 이점과 단점의 식별 ○ IMO 및 회원국 등의 역할 식별 ○ 이행계획을 포함한 추가 개발을 위한 작업계획의 작성 IMO에서 수행되고 있는 e-Navigation 전략 개발 의제 일정은 2008년까지이다. 이 전략 개발에 있어서 중요한 요소는 e-Navigation이 포함할 서비스범위, 포함하는 서비스 제공에 필요한 인프라 및 장비의 식별, 인프라 구축및 운용비용을 부담할 주체에 대한 논의, e-Navigation으로 인한 이익과 투자비용에 대한 비교 분석 등이다. 이 과정에서 정부, 선주, 항만운영자, 선원등의 입장 차이와 선진국과 개발도상국 간의 경제 수준 차이는 전략 개발에있어 큰 어려움을 줄 것이므로, 이들이 합의된 전략을 만들기 위해서는 예정된 기간보다 다소 늦어질 가능성도 있다.e-Navigation 전략 개발이 완료되면 1단계로는 해상교통 관제시스템, 선박선교 장비, 무선 통신장비 등에 대한 표준화 작업이 이루어질 것이다. 이 과정에서 각국 간에 자국 보유 기술을 표준화시키기 위한 경쟁이 치열할 것으로 예상된다. 2단계에서는 e-Navigation 체계 하에서의 다양하고 풍부한 서비스 제공을 위한 관련 소프트웨어 및 하드웨어의 개발이 이루어질 것으로전망되는데, 이는 지난 10년간 육상에서 인터넷망 설치 후 이루어진 관련 서비스 산업의 발전을 돌아보면 쉽게 짐작할 수 있을 것이다.e-Navigation 체계 하에서 선박의 항해는 현재와는 전혀 다른 패러다임으로 바뀔 것이다. 예를 들어 현재 입출항 시 요구되던 복잡한 절차는one-stop 쇼핑 형태로 단순화되고, 현재 선박 중심의 항해에서 육상e-Navigation 센터가 적극적으로 관여하는 항해 체계로 바뀔 것이며, 해상정보의 공유와 활용이 무선 인터넷을 통해 보다 광범위하게 이루어질 것이 다.e-Navigation의 잠재적 시장 규모는 선박에 새로이 탑재될 지능형 통합 항법시스템 구축과 육상 모니터링 및 지원 시스템 등 직접 시장이 약 50조원,전자해도, 통신장비, 관련 서비스 컨텐츠 등 간접 시장의 규모가 150조원으로 총 200조원으로 대략 추산하고 있다. 향후 이 거대한 시장을 차지하기 위한 전략 수립이 필요한 시점이다. 지금까지 항해 장비 관련 산업은 선진국의일부 업체들에 의해 독점되어 왔다. 우리나라는 조선과 해운에서 모두 선진국임에도 불구하고 이 분야에서는 대부분 수입에 의존해 왔다. e-Navigation체계 하에서는 전체 시장이 커지고 장비의 사양이 표준화됨에 따라 어느 소수 업체가 현재처럼 독점하기는 더 이상 어려울 것으로 예상된다. 따라서e-Navigation은 우리나라도 항해 장비 분야 시장을 차지할 수 있는 좋은 기회라고 할 수 있다. 특히 조선 1위의 장점을 적극 활용한다면 다른 나라보다우위의 경쟁력을 확보할 수도 있다. 또한, 서비스 분야의 시장은 IT 기술과밀접한 관계가 있으므로 IT 강국인 우리나라가 충분한 경쟁력을 갖고 있다고 할 수 있다.그러나, EU를 비롯한 선진국에서는 이미 e-Navigation 에 대비한 연구를10여년 전부터 수행해 왔다. 앞에서 언급한 EU의 MarNIS 사업은 현재 거의마무리 단계로 당장 실용화 할 수 있는 수준에 있는 것으로 보인다. 늦었지만 우리도 이를 따라잡기 위한 연구를 서둘러야 할 것이다. 국내에서도e-Navigation의 중요성을 깊이 인식하고, 2006년에는 관련 산학연 전문가들로 작업반을 구성하여 워크숍 등을 개최한 바 있다. 또한 해양수산부에서도e-Navigation 핵심기술 개발을 위한 연구사업을 기획 추진하고 있다.그러나 현재 항해통신장비들의 기술기준은 ITU의 전파규칙(RR)과 IMO결의 및 SOLAS 협약을 따르고 있는데 이들 규약이나 결의에 대한 국제적인 추이와 비교할 때 국내의 기술은 표준화되지 못한 부분이 많은 실정이다.본 연구에서는 e-Navigation sytem중 표준화가 필요한 요소와 전자해도,AIS 등 e-Navigation(통합전자항법시스템)관련 국내산업현황 실태조사를 통해 국내 e-Navigation기술개발 동향에 대해 조사하고자 한다.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.37 no.2
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• pp.389-395
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• 2017

A study was carried out to improve the field implementation of asphalt surface reinforcement method which is a preventive maintenance. Mean Texture Depth (MTD) was measured to quantify the surface condition and used to determine the optimum application rate. Determining the application rate using MTD can reduce the material loss from 30% to 15%. In order to reduce the curing time to 30 minutes, the heat capacity of $317kcal/m^2$ is required. Therefore, the design capacity of the heating curing device requires more than 380,000 kcal/hr. The asphalt surface reinforcement method is preferably applied at a time when slight cracking occurs before the permanent deformation becomes serious. Through the analysis of the pavement survey data, it was decided to apply the surface reinforcement method at the crack rate of 3~4%. Heating the surface reinforcement agent to $50^{\circ}C$ improves workability and ensures sufficient penetration depth even at a crack width of 1 mm. The results will be utilized as basic data for the development of automated construction equipment for efficiency improvement.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.3
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• pp.1645-1651
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• 2015

This paper describes the changes of shape accuracy in workpiece materials depending on the turning clearance angle. The experiments started from choosing three workpiece materials, SM45C(machine structural carbon steel), STS303(stainless steel) and SCM415 (chrome-molybdenum steel). The experiments showed specifically how features of selected materials changed when they were processed with diverse machining depths, 0.1 mm, 0.2 mm and 0.3 mm, with various negative angles, $0.0^{\circ}(-6.0^{\circ})$, $0.3^{\circ}(-6.3^{\circ})$ and $0.9^{\circ}(-6.9^{\circ})$, and called cutting edge inclination starting from a fixed rotational speed, 2,500 rpm, focusing on the feed rate, 0.07 mm/rev and 0.10 mm/rev. The results of the accuracy of processing, cylindricity, deviation from coaxiality, etc. were compared using the graph and table. The accuracy of cylindricity in the order of degree $0.0^{\circ}{\rightarrow}0.3^{\circ}{\rightarrow}0.9^{\circ}$ depending on the workpiece materials showed the best cylindricity when it was $0.9^{\circ}$. In conclusion, the accuracy improved in specific degrees irrespective of the quality of the materials when the bite negative angles increased. This means that workability improved in these experiments. In addition, the processing shape changed depending on depth of the cut and feed rate.

• Journal of the Korea Concrete Institute
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• v.28 no.1
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• pp.3-11
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• 2016

The concern about hollow core PC slab has been increased to improve the workability during a construction of building by reducing self weight of structural members. In this manner, recently, TRS (Tripple Ribs Slab) was developed as a new type of half PC slab system. TRS member consists of the triple webs and the bottom flange prestressed by strands. The slab system is completed by casting of topping concrete on the TRS after filling styrofoam between the webs. This paper, presents a flexural experiment to investigate the flexural capacity of the TRS. Five full scale TRS members were made and tested under simple support condition to be failed by flexure and their strength was evaluated by code equations; the variables in the test are the depth and the presence of topping or raised spot formed when slip-forming. In addition, a nonlinear sectional analysis was performed for the specimens and the result was compared with the test results. From the study, it was found that the TRS has enough flexural strength and ductility to resist the design loads and its strength can be suitably predicted by using code equations. The raised spot did not affect the strength so that the spot need not to be removed by doing additional work. For the more accurate prediction of TRS's flexural behavior by using nonlinear sectional analysis, it is recommended to consider the concrete's brittle property due to slip-forming process in the modeling.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.32 no.5
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• pp.285-295
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• 2020

In the case of small observation towers located at sea, it is necessary to confirm the change in dynamic characteristics due to the influence of environmental loads. In this study, the dynamic characteristics were analyzed and the numerical analysis model was designed through field dynamic response measurement on the Mangyeong Offshore Observation Tower (Mangyeong Tower) located near the Saemangeum Embankment. As a result of the measurement, the natural frequency was found to increase slowly as the tide level is lowered. In addition, it was confirmed that the same mode has two frequencies, which was judged to be a phenomenon in which the natural frequency was partially increased when the pile and the ground contacted by scouring. For numerical analysis, the upper mass, artificial fixity point, scour depth and fluid influences are reflected in the structural characteristics of the Mangyeong Tower. In addition, the model updating from the estimated natural frequency and pattern search algorithm was performed. From the model updating, it is expected that it can be applied to future studies on stability of Mangyeong Tower.

• Journal of Conservation Science
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• v.28 no.1
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• pp.87-94
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• 2012

This study was focused on digital restoration and surface depth modeling applying the three-dimensional laser scanning system of the Haeundae Stone Inscription. Firstly, the three-dimensional digital restoration carried out acquiring of point cloud using wide range and precision scanner, thereafter registering, merging, filtering, polygon mesh and surveyed map drawing. In particular, stroke of letters, inscribed depth and definition appearing the precision scanning polygon was outstanding compared with ones of the wide range polygon. The surface depth modeling completed through separation from polygon, establishment of datum axis, selection of datum point, contour mapping and polygon merging. Also, relative inscribed depth (5~17mm) and outline by the depth modeling was well-defined compared with photograph and polygon image of the inscription stone. The digital restoration technology merging wide range and precision scanning restored the total and detailed shape of the Stone Inscription quickly and accurately. In addition, the surface depth modeling visibly showed unclear parts from naked eye and photograph. In the future, various deteriorations and surrounding environment change of the Stone Inscription will be numerically analyze by periodic monitoring.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.5
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• pp.688-696
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• 2016

This paper evaluates the effect of hot weather conditions on the fresh concrete characteristics of 80-MPa high-strength concrete. The slump flow, packing ability, setting time, hydration heat, and compressive strength were evaluated under exterior temperatures of $20^{\circ}C$, $30^{\circ}C$, and $40^{\circ}C$. The slump flow, arrival speed of 500 mm, and their changes with the elapsed time were found to bring the occurrence of rapid slump loss forward by about 30 minutes when increasing the temperature by $10^{\circ}C$ from $20^{\circ}C$. The initial and final setting times of the concrete at $20^{\circ}C$ were 7 hours and 12 hours, which were reduced by 1 hour and 3 hours at $30^{\circ}C$ and by 2 hours and 5 hours at $40^{\circ}C$, respectively. The hydration heat characteristics at $20^{\circ}C$ and $30^{\circ}C$ were similar in terms of the highest temperature of the concrete casting depth and the time when the maximum temperature occurred. However, at $40^{\circ}C$, the maximum temperature occurred about 4 hours earlier, and the highest temperature per the concrete casting depth increased by about $12^{\circ}C$. Therefore, it is concluded that the characteristics can vary according to the exterior temperature. Thus, quality assurance should consider workability, temperature cracks due to hydration heat, the properties of strength development, and other characteristics.

• Current Research on Agriculture and Life Sciences
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• v.22
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• pp.19-27
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• 2004

Cultivation area of garlics is 9% of all cultivation area of vegetables. The amount of annual demand is increased in 1,000~1,500ton. Also, the amount of demand per person has a tendency to increase as above 10kg. So, garlics has become important crops in agriculture. The purpose of this study is to acquire the basic information to design the garlic seeder attached power tiller. We used Working Model 3D program to design an automatic aligning device which is the most important part of the garlic seeder. The results are as follows; 1. The optimum depth of garlics seeding was shown as 3cm. 2. The garlic seed has to he discharged from the garlic seeder at intervals of 0.75sec in order to seed at intervals of seeds of 15cm. 3. The optimum design factors of the automatic aligning device were shown as cylinder diameter of 4cm, cylinder gap of 1cm, revolution of 36rpm and inclined angle of cylinder of $8.4^{\circ}$.

• The Journal of Korean Academy of Prosthodontics
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• v.49 no.1
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• pp.38-48
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• 2011

Purpose: Dentists suffer back, neck and shoulder pain during their careers due to bad operating posture. If dentists have a good operating posture ergonomically, there would be less pain and discomfort in the shoulder and back. Therefore, dentists should learn the Home position which enables dentists to approach a stable posture ergonomically. This study was to compare tooth preparation in the Home position and the Random position, and evaluate the clinical efficacy of the Home position. Materials and methods: Tooth preparation for fixed partial denture was performed on the maxillary left 2nd premolar and maxillary left 2nd molar at the two different operating positions were compared. The amount of occlusal reduction, marginal width, subgingival margin depth, and convergence angle were measured. A T-test was performed separately to compare the results of the Random position and the Home position. Results: 1. The amounts of average thickness of occlusal reduction on fossa were deficient to the ordered ones in the Random position and the Home position (P > .05). 2. The average subgingival margin depth of prepared margin on maxillary left 2nd premolar, maxillary left 2nd molar were excessive in the Random position than in the Home position. On the maxillary left 2nd premolar, there was no statistical difference in the Random position and the Home position except Distal midline, DL line angle, Lingual midline, ML line angle (P< .05). On the maxillary left 2nd molar, there was no statistical difference in the Random position and the Home position (P < .05). 3. Average convergence angle in the Random position and the Home position were excessive compared to the ordered angle. There was no statistical difference in the Random position and the Home position (P > .05). 4. Analysis of pearson correlation : In the Random position, the amounts of average thickness of occlusal reduction, the average subgingival margin depth of prepared margin, convergence angle were significantly associated with each other (P < .05). But in the Home position, they were not significantly associated with each other (P < .05). 5. The time needed for preparation in the Home position was faster or equal than that of the Random position as time went on. Conclusion: In conclusion, there were no significant differences between Home position and Random position in measures of occlusal reduction, marginal width, marginal depth, convergence angle. However, preparation time and incidence of damaging adjacent teeth were less in Home position than in Random position. Therefore, if trained properly, Home position which is more ergonomically stable can be adopted for clinical use.

• Journal of KIISE
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• v.43 no.5
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• pp.516-523
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• 2016

For old-age makeups, makeup artists first make a mold cast of an actor's face using plaster and then sculpt wrinkles in clay on the plaster mold. After finishing the clay sculpture, its negative plaster mold is fabricated and silicone skin patches are finally made for application to the actor's face. This process takes a few days and is tedious for actors and makeup artists. With recent advances in 3D printing and scanning technology, it is becoming easier to scan and fabricate 3D faces. This paper presents a new pipeline composed of facial scanning, interactive wrinkle modeling, and mold printing stages to easily and efficiently fabricate silicone masks for old-age makeups without the use of plaster and clay. An intuitive sketch interface based on a normal map is proposed for the creation of wrinkles in real time, even with a high-resolution face model. Then the geometry of the final wrinkles is reconstructed using a depth map and the negative mold of the wrinkled face is printed. We also show that the presented pipeline can fabricate a silicone mask more conveniently than the traditional one that consists of pouring silicone into the prepared negative mold and then overlapping the mold with the original positive one.