• Korean Journal of Remote Sensing
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• v.39 no.1
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• pp.23-45
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• 2023

Tuvalu is a small reef islands country in the Pacific Ocean. Its coastal regions are very much dynamic due to the profound effects of tropical cyclones and sea level rise (SLR). However, research works on coastline dynamics of Tuvalu mainly cover its capital, Funafuti. Therefore, this review summarizes the extent of long-term coastal changes in different islets of Funafuti and on overall Tuvalu. In Funafuti, highly accreting areas are Te Afualiku, Fuafatu, Motugie, and Amatuku, and highly eroding areas are Fuagea and Tefala with the fully disappeared islet of Vasafua after 2005. However, in spite of different causes and supposition of scientists on disappearing these lands the accretion is more dominant than erosion which resulted in 7.3% net increase of land areas of Tuvalu over 117 years till 2015. Severe tropical cyclones mainly caused accretion of land areas by forming coral rubble rampart formation and further reworks and erosion to small sandy islands whereas frequent low-energy cyclones mainly caused erosion. Though, till now severe erosion of coastal areas are not evident by global SLR, islets of Funafuti experienced remarkable shoreline increase as formation of 30-40 m wide rubble rampart formation along 19 km in 1971 by tropical cyclone Bebe and net increase of area of 3.45 ha by tropical cyclone Pam in 2015. In spite of such overall accretion of coastal areas several scientists suspect drowning of its areas in future because of high SLR (~5.1±0.7 mm/year) at Funafuti which supposedly will not work as a breakwater anymore. Thus, protection measures should be taken to prevent coastline erosion as well as land reclamation activities should be done following the global examples.

• Proceedings of KOSOMES biannual meeting
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• 2005.05a
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• pp.53-61
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• 2005

Dokdo, a group of 33 small and rocky Islets, in the East Sea have been administered by Korea for years since 1953 and are currently occupied by Korean Police Unit. Located about 217Km off the eastern border of Korea and 87Km east of UIleung Island in North Gyeongsang Province. Situated in the East Sea of Korea, Dokdo itself has valuable strategic implications for Korea as well as another countries such as Russia, Japan, U.SA etc. The first historical testimonies to Dokdo were in Korean documents referring to it as a part of an independent island district known as Ulleung Island(Usanguk), which was incorporated into Silla Kingdom in 512 A.D. in '1454 Sejong Authentic History'. Historically, since at least 1881, the island has been called Dokdo by Koreans, meaning 'Rock Island' or 'Lonely Island'. Also Korea, which regained a full sovereignty and have exercised it for decades continuously, keeps a small police detachment on the Island. That is, Dokdo is under effective control of Korea until today. Therefore Dokdo, which is a problem that is related to our territory and sovereignty, is clearly a cluster of Islands of Korea.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2000.11a
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• pp.301-306
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• 2000

Small passenger and car carrier ships are mainly used as a connection way between land and small islands. And these ships should be designed to enlarge the capacity of passenger and car loading within limited space and draft. So the resonances of various vibrations exist in normal operation range of engine and propulsion shafting. In this paper, hull's superstructure vibration which was especially induced by the 1st order excitation of whirling vibration on the 2-engines and 2-propulsion shafting systems is introduced. Also these are verified via the theoretical analysis using transfer matrix method and FEA software ANSYS and its vibration measurement.

• Journal of Korean Society of Transportation
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• v.27 no.2
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• pp.107-115
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• 2009

Traffic islands were introduced for drivers and pedestrians to use the road in a safe and orderly way and were also a specified zone between traffic lanes to divide conflicting traffic flows and to provide pedestrian refuge. However, existing research and relevant standards described its purpose and effects only but not a safety standard to decide whether the traffic island warranted. This study was to introduce a parameter which had a high relationship with accidents by analyzing road and traffic conditions and traffic accident data at urban intersections. Based on the relationship between the parameter and the traffic accidents at the intersection, a pedestrian accident probability model was made by using a logit model. In addition, the study reviewed a pedestrian accident probability corresponding to traffic volume and size of the intersection during design of the intersection and then suggested the effectiveness of the traffic island in terms of traffic safety. In conclusion, when a large-scale intersection has significant traffic volumes, a high probability of traffic island-induced pedestrian accidents appears, while in the case of small volumes, the probability is low. Targeted design and operations of a traffic islands is necessary, because its introduction itself does not enhance pedestrian safety in all cases at all intersections. This study can be a useful reference for further development to set up a scheme of the traffic islands in terms of traffic safety.

• Journal of the Korean School Mathematics Society
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• v.3 no.1
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• pp.177-188
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• 2000

Mathematics is extreme the differences of the scholarly attainments in comparison with other subjects at a middle school. Specially, the students at islands and places leave much to be desired the scholarly attainments standards of mathematics. Therefore, every school takes movement class according to level these days. And the small schools put in effect the cooperation of group work through the small groups. These classes are effective at the scholarly attainments extension to some degree, but each student is extreme the differences of scholarly attainments. On this, the small school was the subject of study at the present research and put in effect the cooperation of group work through the small groups. The students were divided in three groups; the top class, average, the low class, And they were offered the fitting textbooks matching the cooperation of group work and the opportunities of discovery learning fitting an individual ability and standard. Consequently, some educational materials were made, for example, question papers, commonness learning materials, choice learning materials. These materials were put in effect to the students to be able to succeed discovery learning. With this, the students were investigated an interest of mathematics and the influence giving at the studies attainment. And the students were put in effect the cooperation of group work through the small groups to improve uniformity and sturdiness of the mathematical education. The conclusion at the present research is as follows. 1) When the students put in effect the cooperation of group work through the small groups, the scholarly attainments of mathematics totally didn't display useful changes as improvement. However, the students of average and the low class gradually seemed to improve the scholarly attainments of mathematics as the help of the top class positively. 2) An individual and cooperation learning in the method of the cooperation of group work through the small groups displayed many changes at the learning attitude of the students by means of discovery learning thanks to the learning heads. 3) When the investigator put in effect the cooperation of group work through rather the small groups than the large groups, the numbers of the students experiencing interest about mathematics increased in 26% and this learning method should continue to progress.

• Journal of Hydrogen and New Energy
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• v.30 no.6
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• pp.608-613
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• 2019

The purpose of the present study is to analyze and evaluate the performance of a small Darrieus wind turbine installed at the Urumsil region of Deokjeok-do Island in the west of South Korea 50 km away from Incheon. This place has no government electricity so alternate resources of energy needed to be installed there. For this purpose a small Darrieus wind turbine with the capacity of 1.5 kW was developed and installed at the site. The experimental power output of the wind turbine is less than the designed power at the same values of wind speed. This power loss is mainly due to the highly unsteady nature wind of sudden changes in magnitude of wind speed and wind angle. The results of current study can be used to make a future power generation plan for Deokjeok-do and other nearby small islands.

• Geophysics and Geophysical Exploration
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• v.27 no.1
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• pp.37-50
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• 2024

The magnetotelluric (MT) survey can be affected by external environmental factors. In particular, when acquiring MT data in islands, it is essential to consider the combined effect of topography and sea to understand the results and make accurate interpretations. To analyze the MT response (apparent resistivity, phase) with consideration of the effect of topography and sea, a small cone-shaped island model surrounded by deep sea was created. Two-dimensional (2-D) and three-dimensional (3-D) forward modeling were performed on the terrain model considering topography and the island model considering both topography and sea. The 2-D MT response did not reflect the topographic and sea effect of the direction orthogonal to the 2-D profile. The 3-D MT response included topographic and sea effects in all directions. The XY and YX components of the apparent resistivity were separated on undulating topography, such as a hill. A conductor at 1 km below sea level could be distinguished from topographic and sea effects in the MT response, and low resistivity anomaly was attenuated at greater depths. This study will facilitate understanding of field data measured on small islands.

• Environmental Engineering Research
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• v.20 no.1
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• pp.59-63
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• 2015

About 4,500 mass burial sites of carcasses from the 2010/2011 outbreak of Foot-and-Mouth (FMD) disease in Korea show very slow stabilization speed, although more than 3 years have passed. Therefore, a plan is being considered to boost the speed of stabilization or removal. This is a study on the social value of the removal plan for 4,500 mass burial sites from the 2010/2011 outbreak of FMD in Korea. This valuation is based on the survey of 1,000 people living all over Korea. Korean people have a willingness to pay 101.2 billion Korean Won (about US $100 million). This value is a large amount, but it is small compared to the cost of a FMD outbreak. The cost for the Korean government from 5 outbreaks since 2000 ranged from 28.8 billion Won to 3.2 trillion Won. These were the costs only paid by the Korean government. One estimate reported that there would be a total damage of 1.4 trillion Won, if FMD outbreak occurs in Jeju Islands, a small part of Korea. If burial sites have very slow stabilization speed and some hazardous contents, the social damage will exceed the removal cost.

• The Bulletin of The Korean Astronomical Society
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• v.42 no.2
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• pp.67.3-68
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• 2017

Bright rays are often observed after coronal mass ejections (CMEs) erupt. These rays are dynamical structures along which plasmas move outward. We investigated the outflows along the post-CME rays observed by the COR2 on board STEREO Behind on 2013 September 21 and 22. We tracked two CMEs, two ray tips, and seven blobs using the NAVE optical flow technique. As a result, we found that the departure times of blobs and ray tips from the optimally chosen starting height of 0.5 $R{\odot}$ coincided with the occurrence times of the corresponding recurrent small flares within 10 minutes. These small flares took place many hours after the major flares. This result supports a magnetic reconnection origin of the outward flows along the post-CME ray and the importance of magnetic islands for understanding the process of magnetic reconnection. The total energy of magnetic reconnection maintaining the outflows for 40 hr is estimated at 1.4' 1030 erg. Further investigations of plasma outflows along post-CME rays will shed much light on the physical properties of magnetic reconnection occurring in the solar corona.

• Journal of Korea Port Economic Association
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• v.33 no.3
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• pp.139-154
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• 2017

As competition in domestic and overseas ports intensify, new and small domestic ports are realizing certain limitations to independently secure competitiveness. This study collected data over 60 months with five modifications for container and general cargo volume around Gyeongin Port. Short-period (12 months) cargo volume was forecasted, which revealed the need for a middle-to-long-term development plan. First, the hinterland logistics complex of Gyeongin Port is expected to contribute to the coastal maritime facility through the quasi-public system for fishery product transportation and passenger services. It proposes to achieve this by opening channels to and from China for precision machinery, home network systems, LEDs, and machine industry items. second, specializing the ultra-light cargo transport route, and connecting the coastal island areas of the 5 West Sea Islands to Ara Waterway (Integrated Fishery Product Center of the 5 West Sea Islands). Third, on the basis of organic cooperation of government? local government ? port, the incentive and pre-circular support system would be required, and lastly, it shall carry out the adjustment of functions in nearby ports and specialization strategy simultaneously through the integrated operation of the ports in the capital areas.