• Title/Summary/Keyword: Korean knots

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Reviewing the Explosively Deepening Cyclone(Cyclonic Bomb) over the East Sea with the Satellite Observations (위성관측에 의한 동해상의 폭발적 저기압의 고찰)

  • 정효상
    • Korean Journal of Remote Sensing
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    • v.12 no.2
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    • pp.126-138
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    • 1996
  • The characteristics of rapid development of the low pressure system over the East Sea from 06 to 08 Nov., 1995 has been analyzed in detail by the synoptic numerical products and satellite observations. The Low system was initially triggered the development of the baroclinic leaf cloud over the border of the northern part of Korea and China and moved eastward and then developed explosively com-ma or lambda type cloud system over the East Sea. To forecast well the general development and movement of the coastal winter cyclone over the East Sea popularly in a numerical simulation by several scientists, the large baroclinicity, continuous support of water vapor, and sequential cold outbreak over the warm sea surface have been more commonly concerned about. The cyclone which the central surface pressure was dropped 40hPa within 24 hours has often accompanied strong wind and heavy snow- or rain-fall in the winter season. In all successive observations with 12-hourly satellite imagery and analyzed meteorological variables in this period, the centers of the sea-level pressure and 500hPa geopotential height associated with this cyclone were typically illustrated by moving farther eastward using GMS combined enhanced IR images. The maxi-mum wind sustained by this system with the intensity and central pressure of tropical storm was about 60 knots with the center pressure drop of 44hPa/day similar to the North American cyclonic bomb and Atlantic storm.

Improvement Plan for Myodo-Strait at Yeosu Port (여수항 묘도수로 개선에 관한 연구)

  • Lee, Chang-Hyun;Lee, Hong-Hoon;Kwon, Yu-Min
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.27 no.6
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    • pp.775-782
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    • 2021
  • The Myodo-Strait at Yeosu Port is normally used as a major vessel passage for dangerous cargo carriers that carry regular products of dangerous goods. Currently, the Myodo-Strait allows only single passage, and the speed of passage is also limited to 8 knots. As a result, demurrage at the wharf of hazardous goods are also on the rise. It is expected that the development of a number of dangerous commodity wharf in the future will increase the volume of vessel traffic and increase the number of vessels used in the project area. Therefore, it is urgent to improve the waterway in order to secure the safety of ships using the waterway and improve the demurrage. This study proposed an improvement plan for the waterway through the analysis of the marine environment of the waterway and the process of collecting opinions from users in the sea area. and it was finally proposed to expend the width of the strait to 300m and secure a depth of 9.50m through Guidelines of Port and Harbor Design review and ship handling simulation evaluation. In addition it was evaluated that the vessel traffic congestions at peak-time in the situation of solo passage was greatly improved from 71.01% to 47.3% even when it was allowed to ship's crossing passage, as a result of vessel traffic congestions evaluation. According to the proposed improvement plan, the safety of ships' passage in the project area can be secured, and the issue of demurrage was also considered to be improved.

A Study on Motion Response of Small Fishing Vessels According to Various Tonnage in Regular Waves (소형어선의 크기에 따른 규칙파 중 운동응답 특성에 관한 연구)

  • Im, Nam-Kyun;Lee, Sang-Min
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.27 no.6
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    • pp.832-838
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    • 2021
  • Recently, reports of marine accidents of small fishing vessels less than 10 tons have been increasing. In this study, the characteristics of the motion response in regular waves were analyzed using computations for these ships. Small vessels less than 10 tons are classified by size and used for marine accident investigations. Therefore, the motion response analysis was performed on three small fishing vessels of different sizes. In the case of the head sea, it was confirmed that as the speed of the vessel increased in the long wavelength region, the motion responses of heave and pitch became large. The motion response of the smallest 3-ton fishing vessel was greater than that of the other sizes of fishing vessels. The maximum value of the roll motion shifted to the long wavelength region as the speed gradually increased in the bow sea, regardless of the size of the ship. In all the three small fishing vessels, it was found that the roll motion was the greatest at 15 knots, the highest speed in both bow and beam seas. When sailing in the head sea and bow sea conditions, lowering the speed is one of the effective approaches to reduce the effects of the vertical and lateral plane motions. The roll motion caused by the beam wave showed a tendency to increase rapidly only at a specific wavelength regardless of the speed and the size of the vessel. It was confirmed that the roll motion was significantly reduced with forward speed in the stern wave compared to the bow wave. As there is a specific region where the maximum value of the hull motion response appears depending on the size and speed of the ship, an operation method that can minimize the effect of this motion should be considered and implemented.

A Study on the Scope of Passenger Vessels and Dangerous Goods Carriers Subject to Maritime Traffic Safety Audits (해상교통안전진단 대상 여객선 및 위험화물운반선 범위에 관한 고찰)

  • Lee, Hong-Hoon;Kim, Sung-Cheol;Kim, Deug-Bong
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.23 no.7
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    • pp.767-774
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    • 2017
  • Maritime traffic safety audits (MTSA) were enacted in order to ensure marine traffic safety throughout changes or the construction of water facilities, port facilities, etc. After the introduction of MTSA, the scope of subject vessels was restricted to an LOA of more than 100 m or a maximum speed of more than 60 knots as of 2014. In this study, the scope of subject vessels was re-examined in comparison with specific marine traffic safety areas and tanker prohibited areas identified in the maritime safety act. Furthermore, the state of subject vessels and exception cases for MTSA were also analyzed. As a result of these analyses, MTSA were deemed necessary for dangerous goods carriers of more than 1,000 G/T in specific marine traffic safety areas and dangerous goods carriers of more than 794 G/T in tanker prohibited areas. Finally, the necessity of further review was suggested given the present scope of subject vessels.

Construction of a Bark Dataset for Automatic Tree Identification and Developing a Convolutional Neural Network-based Tree Species Identification Model (수목 동정을 위한 수피 분류 데이터셋 구축과 합성곱 신경망 기반 53개 수종의 동정 모델 개발)

  • Kim, Tae Kyung;Baek, Gyu Heon;Kim, Hyun Seok
    • Journal of Korean Society of Forest Science
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    • v.110 no.2
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    • pp.155-164
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    • 2021
  • Many studies have been conducted on developing automatic plant identification algorithms using machine learning to various plant features, such as leaves and flowers. Unlike other plant characteristics, barks show only little change regardless of the season and are maintained for a long period. Nevertheless, barks show a complex shape with a large variation depending on the environment, and there are insufficient materials that can be utilized to train algorithms. Here, in addition to the previously published bark image dataset, BarkNet v.1.0, images of barks were collected, and a dataset consisting of 53 tree species that can be easily observed in Korea was presented. A convolutional neural network (CNN) was trained and tested on the dataset, and the factors that interfere with the model's performance were identified. For CNN architecture, VGG-16 and 19 were utilized. As a result, VGG-16 achieved 90.41% and VGG-19 achieved 92.62% accuracy. When tested on new tree images that do not exist in the original dataset but belong to the same genus or family, it was confirmed that more than 80% of cases were successfully identified as the same genus or family. Meanwhile, it was found that the model tended to misclassify when there were distracting features in the image, including leaves, mosses, and knots. In these cases, we propose that random cropping and classification by majority votes are valid for improving possible errors in training and inferences.

Alternative Fixation Technique for Bony Bankart Lesion with Using Suture Anchor (봉합나사와 골터널을 이용한 골성 반카르트 병변의 고정)

  • Kim, Byung-Kook;Lee, Ho-Jae;Kim, Go-Tak;Dan, Jinmyoung
    • Journal of the Korean Orthopaedic Association
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    • v.54 no.6
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    • pp.574-578
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    • 2019
  • For the treatment of a bony Bankart lesion accompanied by an acute traumatic shoulder dislocation, anatomical reduction and stable fixation of the bone fragment and glenohumeral ligament are essential to avoid chronic instability or degenerative changes. If the Bankart lesion has large bony pieces or comminuted fragments, it can be difficult to perform precise and secure fixation of the big intraarticular fragment to the fracture site because of the limited visualization of the arthroscopic procedure. In addition, in the case of the open procedure, it requires an extensive surgical dissection to access the fractured fragment, which may cause surgical approach-related morbidity, such as neurovascular complications, delayed subscapularis healing, and increased risk of stiffness. This paper describes an alternative open suture anchor technique for a large bony Bankart lesion, which was secured anatomically with squared knots after a shuttle relay through bony tunnels and adjacent soft tissue and labrum. This technique can achieve anatomical and firm fixation under direct vision, and reduce the number of surgery related morbidities.

Development of the Large-Capacity Mooring Fittings according to MEG4(Mooring Equipment Guideline 4) (MEG4(Mooring Equipment Guideline 4) 적용에 따른 대용량 무어링 피팅 개발)

  • Myung-Su Yi;Kwang-Cheol Seo;Joo-Shin Park
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.29 no.7
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    • pp.950-957
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    • 2023
  • For safe mooring and towing between the ship and port, the equipment must be designed in accordance with the relevant international regulations. However, some small shipyards and engineering companies often do not fully comprehend the core contents. Therefore, the international regulations regarding towing and mooring equipment are reviewed and the bollard and chock are newly developed based on the Mooring Equipment Guideline 4 (MEG4) standards. A bollard is a mooring equipment used to fix a mooring rope to the hull. It has two columns and is mostly used in a figure eight pattern knots under the mooring condition. The chock, which is used to change the mooring rope direction coming into the ship from outside, is manufactured using a casting with curvature. The two mooring equipment are widely used in the stern, bow, and mid-side. Owing to the increase in the size of container vessels and LNG ships, the mooring rope load has increased and the safe working load of the mooring equipment must be revised. This study summarizes and examines the results of the allowable stress method obtained using finite element analysis modelling. To consider the mesh size effect, a reasonable criteria was suggested by referring the existing class guidance. Additionally, the safe working load was verified through nonlinear collapse analysis, and the elastic region against load increments was confirmed. Furthermore, the proposed evaluation method can be used to develop similar equipment in the near future.

Shoes from Pinet to the Present

  • June, Swann
    • Proceedings of the Korea Society of Costume Conference
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    • 2001.08a
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    • pp.11-13
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    • 2001
  • For those unfamiliar with the shoe world, Pinet (1817-1897) was a contemporary of Worth, the great Parisian couturier. So I look at the glamour shoes and the world of haute couture, and indeed the development of the named designer. That is a concept we are all familiar with now. So it is not easy to comprehend the lack of names for the exquisite work before 1850. Straightway I have to say that the number of noted shoe designers is far fewer than famous dress designers, but I will introduce you to some of them, against the background of contemporary shoe fashions. Franc;ois Pinet was born in the provinces (probably Touraine) in 1817, two years after the end of the Napoleonic Wars. His father, an ex-soldier, settled to shoemaking, a comparatively clean and quiet trade. It had a tradition of literacy, interest in politics, and was known as the gentle craft, which attracted intelligent people. We should presume father would be helped by the family. It was usual for a child to begin by the age of 5-6, tying knots, sweeping up, running errands and gradually learning the job. His mother died 1827, and father 1830 when he was 13, and at the time when exports of French shoes were flooding world markets. He went to live with a master shoemaker, was not well treated, and three years later set out on the tour-de- France. He worked with masters in Tours and Nantes, where he was received as Compagnon Cordonnier Bottier du Devoir as Tourangeau-Ia rose dAmour (a name to prove most appropriate). He went on to Bordeaux, where at 19 he became president of the local branch. In 1841 he went to Paris, and in 1848, revolution year, as delegate for his corporation, he managed to persuade them not to go on strike. By now the shoemakers either ran or worked for huge warehouses, and boots had replaced shoes as the main fashion. In 1855 Pinet at the age of 38 set up his own factory, as the first machines (for sewing just the uppers) were appearing. In 1863 he moved to new ateliers and shop at Rue ParadisPoissoniere 44, employing 120 people on the premises and 700 outworkers. The English Womans Domestic Magazine in 1867 records changes in the boots: the soles are now wider, so that it is no longer necessary to walk on the uppers. There is interest in eastern Europe, the Polonaise boots with rosette of cord and tassels and Bottines Hongroises withtwo rows of buttons, much ornamented. It comments on short dresses, and recommends that the chaussure should correspond to the rest of the toilet. This could already be seen in Pinets boots: tassels and superb flower embroidery on the higher bootleg, which he showed in the Paris Exposition that year. I think his more slender and elegant Pinet heel was also patented then or 1868. I found little evidence for colour-matching: an English fashion plate of 1860 shows emerald green boots with a violetcoloured dress.

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The Distribution Characteristics of Floating Debris on the Cruising Routes from Cheju Island to Qindao Harbor in the Yellow Sea (한국 제주도와 중국 청도의 항로상에 부유하는 해양폐기물의 분포에 관한 연구)

  • Kim, Min-Suk;Kim, Jong-Hwa;Kim, Sam-Kon
    • Journal of Fisheries and Marine Sciences Education
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    • v.11 no.2
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    • pp.203-215
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    • 1999
  • Floating debris was recorded from a training ship, Kaya, of Pukyong National University with about 12 knots speed at July 19~21, 1999 and July 24~26. The sampled area is the Yellow Sea (YS) connected from Cheju Is. of Korea to Qindao harbor of China, divided into 88 unit segments on survey routes. Debris fabrication materials were categorized with 6 items using the following; man-made or natural wood items, paper and cardboard, nylon netting and rope, styrofoams, vinyl and plastics, floating metal and glass containers. All identified items within a $120{\pm}20m$ wide band were recorded but ignored if beyond this boundary. The results of distribution of floating debris in the area are as follows: 1. The greatest quantities of marine debris discovered during the survey were $184pieces\;per\;km^2$ near Qindao harbor. The next polluted areas, Sohuksan islands, positioned in the eastern part of YS were scattered in about $40pieces/km^2$ or so. 2. Among items, woods, paper and cardboard, vinyl and plastics were found out near Qindao Coast of China. On the other hand, there were many styrofoams, nylon netting and rope near the area of Sohuksan islands in the eastern part of YS. 3. The distribution densities of western part of YS near Qindao are varied with largely range in items and quantities but those of the eastern part, near Sohuksan islands were nearly constant. 4. Styrofoams were composed of 63% among all debris in YS, next paper and cardboard 15%, and wood item, vinyl and plastics each 10%. Therefore, marine debris of YS is revealed that distribution characteristics and composition are very different in each area. These phenomena are concluded that they largely depend on the life styles in land and the utilities of the sea. And of items, styrofoams is dominated by the distribution pattern of YS. Furthermore, surveys are continuously being investigated, and from this it is hoped that a much wider coverage can be achieved, perhaps all sites of the YS and contributed to the finding sources, the stationary area and removal method of debris joined the flow patterns.

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Evaluation of Structural Performance of 3D Printed Composite Rudder according to Internal Topology Shape (내부 위상 형상에 따른 3D 프린트 복합재 방향타의 구조 성능 평가)

  • Young-Jae Cho;Hyoung-Seock Seo;Hui-Seung Park
    • Composites Research
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    • v.36 no.6
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    • pp.454-460
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    • 2023
  • Recently, regulations on greenhouse gas emissions have been strengthened, and the International Maritime Organization (IMO) has been strengthening greenhouse gas regulations with a goal of net 'zero' emissions by 2050. In addition, in the shipbuilding/offshore sector, it is important to reduce operating costs, such as improving propulsion efficiency and lightening structures. In this regard, research is currently being conducted on topology optimization using 3D printed composite materials to satisfy structural lightness and high rigidity. In this study, three topology shapes (hexagonal, square, and triangular) were applied to the interior of a rudder, a ship structure, using 3D printed composite materials. Structural analysis was performed to determine the appropriate shape for the rudder. CFD analysis was performed at 10° intervals from 0° to 30° for each rudder angle under the condition of 8 knots, and the load conditions were set based on the CFD analysis results. As a result of the structural analysis considering the internal topology shape of the rudder, it was confirmed that the triangular, square, and hexagonal topology shapes have excellent performance. The rudder with a square topology shape weighs 78.5% of the rudder with a triangular shape, and the square topology shape is considered to superior in terms of weight reduction.