• Journal of the Korean Society of Marine Environment & Safety
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• v.25 no.2
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• pp.189-200
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• 2019

Korean seafarers have played a key role throughout the country's history and economic development. They have been a major source of foreign remittance into the nation as well as a pivotal sector in emergency logistics during war times. However, the current number of Korean seafarers in decreasing due to low job attractiveness and retention rate onboard. This is a major problem for the national and international shipping industry as youth seem not to be interested in working onboard for long periods of time. The purpose of this study is to 1) determine what the public opinion about seafarers in Korea is and 2) find out what factors mostly stand out in the public opinion about seafarers profession. The paper suggests that three main types of opinion groups emerged. The first type is labeled as 'high risk, high workload and high stress' as respondents recognized a high possibility of accident onboard and, at the same time, acknowledged that seafarers can be fatigued and stressed. The second type was named as 'Dangerous, Dirty, Difficult', as seafarers' image was mainly associated to fishing vessels and not to merchant and passenger ships. The third type recognized that the social position of the seafarers was low due to 'low social recognition'. The study suggests that all three types have a negative image of seafarers' job. Based on the results of this study, it is necessary to establish various policies and marketing tools to improve the negative job image linked to seafarers by the public opinion. If the public image of seafarers can be improved and attractiveness rose, it is expected a higher number of seafarers will pursue and keep a career at sea.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.57 no.3
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• pp.236-245
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• 2021

In this study, a drifting test using a experimental vessel (2,966 tons) in the northern waters of Jeju was carried out for the first time in order to obtain the fundamental data for drift. During the test, it was shown that the average leeway speed and direction by GPS position were 0.362 m/s and 155.54° respectively and the leeway rate for wind speed was 8.80%. The analysis of linear regression modes about leeway speed and direction of the experimental vessel indicated that wind or current (i.e. explanatory variable) had a greater influence upon response variable (e.g. leeway speed or direction) with the speed of the wind and current rather than their directions. On the other hand, the result of multiple regression model analysis was able to predict that the direction was negative, and it was demonstrated that predicted values of leeway speed and direction using an experimental vessel is to be more influential by current than wind while the leeway speed through variance and covariance was positive. In terms of the leeway direction of the experimental vessel, the same result of the leeway speed appeared except for a possibility of the existence of multi-collinearity. Then, it can be interpreted that the explanatory variables were less descriptive in the predicted values of the leeway direction. As a result, the prediction of leeway speed and direction can be demonstrated as following equations. Ŷ₁= 0.4031-0.0032X₁+0.0631X₂-0.0010X₃+0.4110X₄ Ŷ₂= 0.4031-0.6662X₁+27.1955X₂-0.6787X₃-420.4833X₄ However, many drift tests using actual vessels and various drifting objects will provide reasonable estimations, so that they can help search and rescue fishing gears as well.

• Korean Journal of Remote Sensing
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• v.39 no.1
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• pp.77-86
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• 2023

Ship detection is widely used in areas such as maritime security, maritime traffic, fisheries management, illegal fishing, and border control, and ship detection is important for rapid response and damage minimization as ship accident rates increase due to recent increases in international maritime traffic. Currently, according to a number of global and national regulations, ships must be equipped with automatic identification system (AIS), which provide information such as the location and speed of the ship periodically at regular intervals. However, most small vessels (less than 300 tons) are not obligated to install the transponder and may not be transmitted intentionally or accidentally. There is even a case of misuse of the ship'slocation information. Therefore, in this study, ship detection was performed using high-resolution optical satellite images that can periodically remotely detect a wide range and detectsmallships. However, optical images can cause false-alarm due to noise on the surface of the sea, such as waves, or factors indicating ship-like brightness, such as clouds and wakes. So, it is important to remove these factors to improve the accuracy of ship detection. In this study, false alarm wasreduced, and the accuracy ofship detection wasimproved by removing wake.As a ship detection method, ship detection was performed using machine learning-based random forest (RF), and convolutional neural network (CNN) techniquesthat have been widely used in object detection fieldsrecently, and ship detection results by the model were compared and analyzed. In addition, in this study, the results of RF and CNN were combined to improve the phenomenon of ship disconnection and the phenomenon of small detection. The ship detection results of thisstudy are significant in that they improved the limitations of each model while maintaining accuracy. In addition, if satellite images with improved spatial resolution are utilized in the future, it is expected that ship and wake simultaneous detection with higher accuracy will be performed.

• Korean Journal of Environment and Ecology
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• v.36 no.6
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• pp.575-581
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• 2022

Brown rats (Rattus norvegicusBerkenhout, 1769) were eradicated from Sasudo Island (33°55'13.04" N, 126°38'19.98" E), an uninhabited island designated as Natural Monument No. 333 and the largest breeding site for the streaked shearwater (Calonectris leucomelasTemminck, 1835) in South Korea. Twelve eradication studies were conducted from November 2015 to February 2021. The survey was conducted using a line census method that entailed slow wandering throughout the island and identifying starting and returning points. Capture traps were installed around traces of Rattus norvegicus,such as excrement and identified holes. As a result, 2 to 6 individuals were captured at each instance, except for the last time, when no individuals were captured. It is hypothesized that brown rats arrived at Sasudo Island via vessels arriving at the island for leisure and fishing. After the damage to streaked shearwater caused by brown rats was confirmed in 2006, entry to Sasudo Island was strictly prohibited through security measures, and marine clean-up programs that began in 2013 and continuous capturing since 2015 have been successful in eradicating brown rats. To maintain and manage the condition in Sasudo Island, preservation and management measures, such as strict visitor control, are necessary to prevent the inflow of new brown rats in the future.

• Journal of the Korean Society of Marine Environment & Safety
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• v.29 no.7
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• pp.812-818
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• 2023

During the years 2016 to 2020, the Ministry of Oceans and Fisheries embarked on a strategic initiative to develop a comprehensive Korean e-navigation system, which encompassed the establishment of an 'Long Term Evolution for Maritime (LTE-M).' The primary objectives were to proactively align with international navigation standards and enhance maritime safety for small vessels, particularly fishing boats. However, limitations were identified in the utilization of this network, primarily its constrained application for specific purposes. In response to these limitations, this study delves into user-centric investigations through surveys and interviews, with the goal of expanding the horizon of network utilization. User requirements emerged as the result of study, emphasizing the need for broader network applications, a wider range of target users, diverse network utilization methods, and regulatory streamlining. The user-driven insights gleaned from this study hold the potential to inform and shape future legislative measures, fostering more versatile and inclusive LTE-M network utilization for enhanced maritime safety.

• The Korean Journal of Air & Space Law and Policy
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• v.35 no.1
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• pp.181-202
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• 2020

The Non-Appropriation Principle was stipulated in the OST and the MA. However the MA, creating CHM in international law for the first time, attempted to further limit the prohibitions to include ownership of resources extracted from celestial bodies, its rejection by the U.S. and most of the international spacefaring community prevented it from serving as a binding international treaty. Individuals or private enterprises intending to perform space exploitation must receive approval from the nation and may not appropriate outer space or celestial bodies. In the course of this space activity, each party will be liable. Articles 6 and 7 of the OST and the Liability Convention of 1972 deal with matters concerning those problems. The CSLCA of 2015 and Luxembourg Space Resources Law of 2017 allows States to provide commercial exploration and use of space resources to their own nationals and to companies operated by other countries within their territory. These laws do not violate Article 2 of the OST. In the case of the CSLCA of 2015, the law clearly states that it cannot claim ownership, sovereignty or jurisdiction over certain celestial bodies. Even if scholars claim that the U.S. CSLCA and Luxembourg Space Resources Law violate the non-appropriation principle of the OST, they cannot prevent these two countries from extracting the space resources on "the first come, first served" basis. The legal status of outer space including the moon and other celestial bodies is res extra commercium, like the high seas, where the fishing vessels from each country catch and sell fish without occupying the sea. Major space-faring nations must push for the adoption of an international regulatory committee which will oversee applications and issue permits based on a set of robust, modern, and forward-thinking ideals that are best equipped to govern and protect outer space as individuals, businesses, and nations compete to commercialize space through mining and the extraction of space-based resources. The new Corpus Juris Spatialis on the development of space resources, whether it is a treaty or a soft law such as recommendation and declaration, in the case of the Moon and Mars, will cover a certain amount of area to develop, and the development period by the states should be specified.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.39 no.4
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• pp.347-357
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• 2003

This paper describes on the suppression of sea clutter on marine radar display using a cell-averaging CFAR(constant false alarm rate) technique, and on the analysis of radar echo signal data in relation to the estimation of ARPA functions and the detection of the shadow effect in clutter returns. The echo signal was measured using a X -band radar, that is located on the Pukyong National University, with a horizontal beamwidth of $$3.9^{\circ}$$, a vertical beamwidth of $20^{\circ}$, pulsewidth of $0.8 {\mu}s$ and a transmitted peak power of 4 ㎾ The suppression performance of sea clutter was investigated for the probability of false alarm between $l0-^0.25;and; 10^-1.0$. Also the performance of cell averaging CFAR was compared with that of ideal fixed threshold. The motion vectors and trajectory of ships was extracted and the shadow effect in clutter returns was analyzed. The results obtained are summarized as follows；1. The ARPA plotting results and motion vectors for acquired targets extracted by analyzing the echo signal data were displayed on the PC based radar system and the continuous trajectory of ships was tracked in real time. 2. To suppress the sea clutter under noisy environment, a cell averaging CFAR processor having total CFAR window of 47 samples(20+20 reference cells, 3+3 guard cells and the cell under test) was designed. On a particular data set acquired at Suyong Man, Busan, Korea, when the probability of false alarm applied to the designed cell averaging CFAR processor was 10$^{-0}$.75/ the suppression performance of radar clutter was significantly improved. The results obtained suggest that the designed cell averaging CFAR processor was very effective in uniform clutter environments. 3. It is concluded that the cell averaging CF AR may be able to give a considerable improvement in suppression performance of uniform sea clutter compared to the ideal fixed threshold. 4. The effective height of target, that was estimated by analyzing the shadow effect in clutter returns for a number of range bins behind the target as seen from the radar antenna, was approximately 1.2 m and the information for this height can be used to extract the shape parameter of tracked target..