• KSCE Journal of Civil and Environmental Engineering Research
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• v.29 no.3B
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• pp.231-237
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• 2009

This study presents a numerical model to simulate density currents developing two dimensionally. The ${\kappa}-{\varepsilon}$ model is used for the turbulence closure. Elliptic flow equations are solved by the finite volume method. In order to investigate the applicability of the numerical model, discontinuous density currents are simulated numerically. The vortices due to the instability at the interface are simulated, showing a good agreement with the experimental visualizations in the literature. It is also investigated that the transition from slumping phase to inertial phase occurs when a bore generated at the end wall overtakes the front. However, the propagation of the density current is retarded compared with the experimental results. Two-dimensional modeling seems to have an effect on underestimating the front velocity of the density current.

• Journal of the Economic Geographical Society of Korea
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• v.14 no.3
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• pp.407-418
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• 2011

The southern region including Guangzhou(黃州), the capital of Guangdong Province, was called "South of the Mountain Range" (嶺南) because it is located south of the Five Mountain Ranges (五嶺) which made mobility difficult prior to unification of China by Qin dynasty (秦) in 221 BCE. The Guangdong region of the South of the Mountain Range (嶺南) was an administratively independent unit and, as such, called the Nanyue kingdom (南越國). This is the origin of the Chinese character "yue", and terms such as yueyu (Cantonese), yuecai (Cantonese cuisine), yueju (Cantonese opera) are still in use today. Guangzhou, called Panyu (番禹) during the Nanyue kingdom period, was settled early in the northern part of the Pearl River (珠江, Zhu Jiang) delta. It became the first port to open its doors to the great powers of the West during the Qing period. Although it has now fallen behind Shanghai which developed later, Guangzhou is still the third largest city after Beijing and Shanghai, and thus, it is an influential open coastal city. Today, not only is Guangzhou the world center of the light textile industry, it also spurs development in various manufacturing industries. Along with nearby Hong Kong, Macao, and Shenzhen, it plays the role of cradle of the Pearl River delta economic zone. Firmly established early on as the greatest central city in southern China, Guangzhou is simultaneously a hub in various aspects such as regional politics, economics, and culture; it was also the center of revolution and resistance which attempted to challenge the northern political powers. Guangzhou is known for the history of the rise and fall of its port, but with developmental efforts, it still maintains its influence. Guangzhou's dynamic development of today brings with it issues such as the environment and moral system which must be dealt with.

• Journal of the Korean Institute of Navigation
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• v.16 no.3
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• pp.43-53
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• 1992

1992년 전반기에 우리나라에 근해해운기업 3개사가 도산하였으며, 많은 그해해운기업이 심한 경영상의 어려움을 겪고 있다. 그러한 도산이유를 대별하면 기업 내적요인과 기업 외적요인으로 나눌 수 있을 것이다. 이 논문에서는 기업외적 요인의 하나로서 근해지역에 있어서의 선박의 과잉공급과 운임의 덤핑을 상정하고서 최근 소련의 연방해체 이후 극동지역에서 생성되기 시작한 러시아의 해운사기업의 생성배경 및 경영형태를 분석하고, 그러한 러시아의 해운사기업이 보유하고 있는 선박이 우리나라의 근해해운시장에 미치는 영향을 살펴본 뒤 이에 대처하기 위한 우리나라 해운정책의 기본방향을 제시한다. 이 논문의 목적을 달성하기 위하여 사용된 연구방법은 문헌조사, 현장조사, 그리고 면접법이다. 본 연구는 러시아 해운사기업의 생성근원이 되는 국영해운기업, 실제로 극동지역에서 경영되고 있는 러시아의 해운 기업 및 러시아 연방정부의 교통부산하 해운국을 방문하여 각 조직의 최고 책임자 및 주요 인사를 대상으로 면접과 현장조사를 실시하였으며, 일본 및 러시아의 해운연구기관의 주요인사와 우리 나라의 해운기업의 최고경영자들도 본 연구의 면접대상에 포함되었다. 이 연구에서 도출된 주요 결과로서는 첫째, 러시아의 해운사기업은 소련연방산하에 이었던 국영해운기업에서 제공된 매운 낮은 용선료의 선박과 우리나라의 근해선사 또는 대리점과의 노우 하우(know-how) 의 결합에 의해 생성되었으며 둘째, 그러한 매커니즘에 의해서 우리나라 근해지역에 영업활동중인 러시아 선박은 재화중량톤수 약 4천 내지 5천톤에 해당하는 하천.해상형태(river sea type)의 살물선으로서 총 40여척에 달하고 있으며, 셋째, 그러한선박의 용선료는 1992년 3월에 현재 우리나라 근해해운시장에서 형성된 용선료 수준의 50% - 60%에 해당하며, 넷째, 우리나라의 근해화물을 원활하게 확보.수송하기 위하여 일부의 선박은 편의치적국의 선적을 이용하여 운항되기도 한다. 이 연구의 결과를 바탕으로 한 정책적 제언은 경영기술, 자본력, 선박의 질적수준 및 경쟁의 측면에서 일본보다도 취약한 상태에 있는 우리나라의 근해해운을 성장.발전시키기 위해서는 정부는 먼저 연안해운에 적용시키고 잇는 면허제도를 점진적으로 개방화시켜 우리나라의 연안해운의 자본력을 증강시키고 경쟁원리에 의한 경쟁력을 제고시켜야 하며, 제 2선적제도의 발달과 해운경영의 국제성에 맞추어 근해해역에서 활동하는 우리나라의 선박에대해서 부분적으로 선박의 국적을 점차 개방시켜 나가는 정책을 검토해야 할 단계라는 것이다. 이러한 점에 있어서 지난 30여년간 외항해운부문에 중점을 두어온 우리나라의 해운정책은 이제 근해해운정책의 개발에도 관심을 기울여야 하는 전환점에 있다고 할 수있다.

• Journal of Environmental Policy
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• v.8 no.1
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• pp.97-127
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• 2009

In Germany, North Sea and East Sea possess significant meaning in many aspects. North coast has an important economical significance to North Sea Gulf States. There are a number of harbors and manufacturing facilities in this area. Agriculture is also developed. East sea, where sea water and river water mingle. has a problem that it can not control harmful substances as fast as the North Sea due to its geographical location of being connected with the North Sea as a narrow water. To protect from big and small ship accidents and pollution sources, East Sea and North Sea have enacted HELKOM Convention and OSPAR Convention, respectively. Moreover, Denmark and Germany have made cooperation on tugboats in the occurrence of shipment accidents through the LethGer-Plan and DenGer-Plan. In 1998, after the Pallas accident that occurred near Bremen, the need to improve cooperation among each states on usable resources for ocean security has been increased in Germany. Consequently, the federal government and gulf state governments associated and organized the so called, "Havarie-Kommanando Ship Accident Measure Unit". Haravarie-Kommanando is a federal-state associated organization that deals with affairs that controls national operation and mobilization of ship accident related organizations unitively when serious ship accidents occur. Moreover, federal and state participant organizations, each shipping agencies and Wiking-Helicopers-Services, a helicopter agency, are cooperating well. Also, mutual assistance with the most prominent passenger agency called Scandlines, ARGE Kuestenschutz(Germany-Denmark shipping agency) is making progress as well.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.24 no.5
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• pp.433-441
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• 2006

With a development of electrical technology in recent, it is possible to measure distance without direct contact to object using laser which launched at instrument and reflect from object. Furthermore, the advent of non prism total station brought the increment of application in many fields including not only road, airport, and harbors but also measurement and monitoring of structural displacement in construction fields. In this study, therefore, to evaluate accuracy of non prism total station, accuracy was analyzed by measuring certain distance which classified by both certain materials and angle of reflection. By this method, the derived values were applied to topographical survey for the efficient applicability. According to a study, result value of non prism total station was satisfBctory regardless of material when the angle of reflection was 90 degrees. RMSE increased when the angle of reflection are gradually increased to acute angle. In result of regression analysis using certain distance which classified by both materials and angles of reflection, there is relationship between distance and angle of reflection, but material has no relevance to the result value. When carrying out general topographical survey, proper application of non prism total station will go far conducting safe and prompt survey at the dangerous site such a road which have lots of traffic flow and rock joint which have high angles of inclination.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.4 no.3_4
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• pp.92-98
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• 1971

With Saxidomus Purpuratus which were sampled near Yungdo, in the harbor of Pusan during the period from September 1967 to October 1968, the author investigated the maturity against seasonal change of water temperature; and shell length, height and width against live weight, respectively, and the reciprocal correlations of shell length, height and width, as well. The maturity, concerned deeply with tile developing procedure of gonad, is dependent on the change in water temperature. The value of maturity becomes higher from March to May, but in August with high temperature the value decreases temporarily. During the main spawning season from the late August to the middle of October, the value shows the peak throughout a year. After the period, it has decreased until January when the water temperature is below $10^{\circ}C$ The equations of shell length against live weight for male($W=0.4749L^{2.62307}$)and for female ($W=0.3438L^{2.77993}$) shell height against live weight ($W=0.3221L^{3.06661}$), and shell width against live weight ($W=3.5868L^{2.46646}$), show non-straight lines respectively. On the other hand, th: equations of shell length against shell height Y=0.818x+0.292 (r=0.958), shell length against shell width Y=0.520x+0.200 (r=0.799) and shell height against shell width Y=0.499x+0.516 (r=0.773) show straight lines, respectively.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.33 no.6
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• pp.383-390
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• 2021

The experiments in coastal engineering are very complex and a lot of components should be concerned. The experience has an important role in the successful execution. Hydraulic model experiments have been improved with the development of the wave generator and the advanced measuring apparatus. The hydraulic experiments have the advantage, that is, the stability of coastal structures and the hydraulic characteristics could be observed more intuitively rather than the numerical modelings. However, different experimental results can be drawn depending on the model scale, facilities, apparatus, and experimenters. In this study, two-dimensional hydraulic experiments were performed to suggest the guide of the test wave(random wave) generation, which is the most basic and important factor for the model test. The techniques for generating the random waves with frequency energy spectrum and the range for the incident wave height [(H_S)_M/(H_S)_T = 1~1.05] were suggested. The proposed guide for the test wave generation will contribute to enhancing the reliability of the experimental results in coastal engineering.

• Journal of the Korean Society of Marine Environment & Safety
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• v.28 no.5
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• pp.764-772
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• 2022

The shipping and port industries have traditionally been male-centered, and although the scope of entry for female mariners is increasing, the proportion of female workers is still low. However, research on career barriers and career decision levels in this industry has not yet been conducted. This study can explain the dif iculties in career development experienced by women in this industry and comprehensively explain the socio-cultural context or environmental factors to which the individual belongs in order to improve it. The purpose of this study was to derive career barrier factors and investigate how they affect career decision levels among female students enrolled in M University's Maritime College. The career barriers perceived by female students at Maritime College were derived from gender discrimination (GD), career undecided and lack of preparation (IOU), work-family conflict (WFC), lack of individual characteristics (LPQ), and lower-than-expected job prospects (LOE). As a result of analyzing how the derived career barrier factors af ect the career decision level, it was found that IOU had a significant negative effect on the career decision level. GD, WFC, LPQ, and LOE did not have a significant effect on career decision level. The study conclusions can be used as important data for career guidance and counseling for female maritime college women who want to overcome career barriers and improve their career decision-making levels.