• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.21 no.2
• /
• pp.401-408
• /
• 2017

Recently, the environment at littoral sea has been contaminated and damaged by submarine deposits, e.g. the fishing nets. To solve this problem, the government pushes the policies such as management plan of the fishing nets in whole life cycle of them. The representative causes are dumping and drifting away of the fishing nets, and shed new light on technological methods for tracking and management of the fishing nets. To prevent this drawbacks, this paper covers a development of tracking and management system for the fishing nets. To do this, we analyzed the existing products, and figured out performance improvement points. Also we proposed additional enhancement techniques which connects with a smartphone application and displays the positions and state information of the fishing nets, and so on. To adopt the proposed methods, we design and implement a tracking and management system based on ENC with the smartphone application, and verified the usefulness of the system.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.18 no.2
• /
• pp.472-477
• /
• 2017

Oil spills cause a lot of damage to the environment. Oil destroys the water environment and ecosystem in a very short period of time once they are contaminated by it, it takes a lot of time to recover from the contamination and the cleaning process is very difficult. Therefore, oil detectors are greatly needed as they can monitor any oil spills over the sea, rivers, and lakes. There are two kinds of technology available for detecting oil, viz. the contact and non-contact types. The former is based on the use of the conductivity, capacitance and microwaves, while the latter employs infrared, UV, laser, optic and radar technologies. As there are also various hurdles in the measuring of oil on water, such as the presence of waves, refraction of light, temperature and saltiness, it is imperative to select the right oil detector which is appropriate for the specific environment. In this study, a contact type oil detector is developed, which can be used in oil related industries, such as refineries, petrochemical companies, and power generation stations. The detector is made up of the sensor module, which floats on the water, and the controller which processes the signal coming from the sensor module and displays it. It is designed in such a way that the existence of oil is detected through the sensor and the change in the permittivity is observed to determine the volume and type of spilled oil.

• Korean Journal of Food Science and Technology
• /
• v.34 no.3
• /
• pp.529-532
• /
• 2002

The angiotensin converting enzyme (ACE) inhibitory activity in peptic hydrolysate of raw anchovy cooking discards was 51.3% at 1 mg of protein per $100\;{\mu}L$ sample solution. While, after the treatment of pepsin for 4 h, was 65.8%. The crude peptides fractionated through Bio-gel P-2 column chromatography consisted of five fractions $({P-1}{\sim}{P-5})$ and had maximum inhibitory activity in the fraction P-2 ($IC_{50}$=0.319 mg protein/mL). The fraction P-2 was rich in aspartic acid, glutamic acid, and glycine.

• The Journal of the Convergence on Culture Technology
• /
• v.5 no.4
• /
• pp.373-378
• /
• 2019

In the marine area, the salt concentration in the soil increases, and the inland heavy metal pollution increases the damage of plants. In the inland industrial development area, researches on the genetic resources of plants together with the heavy metal accumulation of Co, Ni, Zn, and so on are required. Both of these problems have caused scientists to work hard to find plants that are likely to cause stress in plant roots. In this study, seeds of Arabis stelleri var. japonica collected near the shore were used for germination. The growth and development and tolerance of both Arabis and Arabidopsis seeds were investigated under laboratory culture conditions. As a result, Arabis showed resistance about 3 times in 250 mM nickle and cobalt, and more than 4 times in 1 mM zinc when compared to Arabidopsis. The tolerance of Arabis to Na salts increased by 20% or more at 50 mM concentration and Arabis was resistant to heavy metals and salt concentration. The accumulation of Na ions in the body was measured as a preparation for studying the intracellular mechanism. As a result, it showed a further decrease in resistance to ground water roots. It is considered that the activity of the exporting gene is important rather than the mechanism of accumulation.

• Journal of the Korea institute for structural maintenance and inspection
• /
• v.24 no.6
• /
• pp.180-188
• /
• 2020

To replace Japanese coal ash used in the domestic cement production and to recycle large quantities of domestic pond ash, it is essential to develop the technologies for quality control of cement by using the domestic pond ash. Thus, in this study, the feasibility of using the pond ash as a raw material for cement was investigated through chemical composition and microstructure analysis. As a result, most of the domestic pond ash contained slightly more Fe2O3, chloride, and unburned carbon contents than Japanese coal ash. In particular, the contents of chloride were considerably low in the pond ash that was transferred to fresh water or collected from surface of landfill area. However, since circulating fluidized bed boiler coal ash had relatively high SO3 contents causing durability problems of cement, it was not suitable for use as a raw material for cement. Thus, to replace Japanese coal ash with the domestic pond ash, it is necessary to introduce the adjustment of mixture proportion of cement raw materials and the process of removing chloride in the pond ash.

• Journal of the Korean earth science society
• /
• v.43 no.1
• /
• pp.140-150
• /
• 2022

This paper focuses on introducing the concept of the multi-scale study on the Ulleungdo-Dokdo Volcanic Group in the East Sea and recent new findings from it. Multi-channel seismic reflection data reveals that the major volcanic activities of the Ulleungdo-Dokdo Volcanic Group took place between 5 and 2.5 Ma, which were propagated from Isabu Tablemount on the eastern end to the Ulleung Island on the western end. The terrestrial Ulleung Island was built via 5 stages, which eventually formed a 3 km-wide caldera, named Nari Caldera, and a volcanic dome, named Albong, within the caldera. The Albong and the unit N-1, the earliest phreatomagmatic explosive phase of the Albong volcano, were generated from a new magma injected into the existing phonolitic body. The generally trachyandesitic bulk rock composition of the pumice in unit N-1 and Albong is attributed to the contamination of the new magma by mafic cumulates at the base of the existing phonolitic chamber. The lines of evidence of a new magma injection point toward that Ulleung Island is an active volcano with a live subvolcanic magma plumbing system.

• Asia-pacific Journal of Multimedia Services Convergent with Art, Humanities, and Sociology
• /
• v.6 no.3
• /
• pp.383-391
• /
• 2016

Ballast water provides stability and manoeuvrability to a ship. Foreign harmful aquatic organisms, which were transferred by ballast water, cause disturbing ecosystem. In order to minimize transference of foreign harmful aquatic organisms, IMO(International Maritime Organization) adopted the International Convention for the Control and Management of Ship's Ballast Water and Sediments in 2004. If the convention take effect, a port authority might need to check that ballast water is properly disposed of. In this paper, we propose a method of counting harmful aquatic organisms in ballast water thorough image processing. We extracted three samples from the ballast water that had been collected at Busan port in Korea. Then we made three grey-scale images from each sample as experimental data. We made a comparison between the proposed method and CellProfiler which is a well known cell-counting program based on image processing. Setting of CellProfiler is empirically chosen from the result of cell count by an expert. After finding a proper threshold for each image at which the result is similar to that of CellProfiler, we used the average value as the final threshold. Our experimental results showed that the proposed method is simple but about ten times faster than CellProfiler without loss of the output quality.

• Proceedings of the Korea Water Resources Association Conference
• /
• 2020.06a
• /
• pp.18-18
• /
• 2020

금강하구와 같이 막힌 대형 하구는 근본적으로 복잡한 물리화학적 프로세스와 다양한 이해당사자간의 갈등 때문에 단편적인 접근으로는 관리의 한계가 있을 수밖에 없는 환경이다. 더욱이 하굿둑의 갑문을 열어 하구순환을 복원하는 해수유통 사업은 그 자체가 가지는 환경적 효용성의 확인과 기존 용수이용 체계의 전면적 변화와 관련된 상당한 비용이 요구된다는 면에서 특별한 논란이 되어왔다. 본 연구는 해수유통으로 인한 금강 하구해역의 수리, 수질, 퇴적 및 생태 등 다양한 환경적 변화를 집중적인 현장 조사 및 통합 모델링을 통해 정량적으로 예측하고 이를 지역 이해당사자 논의 체계인 금강하구해역정책협의회에 제공함으로써 해수유통과 연관된 이해당사자 간 갈등을 완화하고 과학적 자료에 근거한 정책결정을 지원하기 위해 수행되었다(과학-정책의 통합). 조사연구는 하굿둑 갑문 개방에 따른 다양한 시나리오별로 해수유통으로 인한 영향을 하구해역(하굿둑의 바다 쪽 해역)과 하구호(하굿둑의 하천 쪽 담수역)에 미치는 영향을 검토하였다(하천-하구호-연안해역의 공간적 통합). 시나리오는 하구해역정책협의회의 요구사항을 반영하여 개발되었고, 시나리오별 영향파악은 수리(조석 및 파랑 포함), 퇴적물 이동 및 수질은 Delft3D모델을, 유역으로부터의 유량 및 오염물질 부하량은 분포형 비점모델인 STREAM을, 김양식과 이매패류 생산량을 추정하는 생태모델은 통계기반의 포인트 모델을 통해 이루어졌다(수리-퇴적-수질-생태계 모델의 통합). 시나리오 분석결과, 상시 해수유통을 제외한 대부분의 하굿둑 부분 개방 시나리오에서는 하구해역에 미치는 영향이 제한적으로 나타나는 것으로 예측되었다. 이는 하굿둑 부분 개방에 따른 담수방류량 및 이에 대응하는 해수의 유동패턴이 현재와 크게 달라지지 않음을 반영한다. 반면 하구호에 대한 영향은 하구해역에 비해 하굿둑 갑문 운영시나리오에 따라 상대적으로 민감하게 변화되는 것으로 예측되었다. 갑문의 부분 개방을 통해 하구호의 수위를 현재 대비 5cm~50cm 변화시켰을 때 1psu 염분의 저층에서의 침투거리는 하굿둑 상류 6km~18km 정도로 예측되었고 갑문 개방에 의해 염분 침투 거리의 조절이 가능할 것으로 나타났다. 단, 사용된 통합모델은 수년간의 검보정 과정을 반복적으로 수행하여 예측의 정확도를 지속적으로 개선하였지만, 모델운영 자체의 불확실성을 고려할 때 실제 해수유통을 위해서는 시범개방을 통해 모델 예측의 결과를 확인할 필요가 있다.

• Analytical Science and Technology
• /
• v.21 no.4
• /
• pp.304-315
• /
• 2008

The total suspended particles (TSP) collected at the 1100 site of Mt. Halla have shown higher compositions for the anthropogenic components followed by marine and soil originated ones. The concentrations of the soil originated nss-$Ca^{2+}$, Al, Fe, Ca components have been increased in spring, and the anthropogenic $NH{_4}^+$, $K^+$, nss-$SO{_4}^{2-}$ components showed high concentrations in June. Meanwhile, the concentration of $NO{_3}^-$ as same as nss-$Ca^{2+}$ was higher in spring. It's likely due to the influence of its long-range transport from China. Compared to the non-Asian Dust periods, the concentrations of nss-$Ca^{2+}$, Al, Ca, and Fe have been increased 7.2~9.5 times in Asian Dust storm periods, and those of nss-$SO{_4}^{2-}$ and $NO{_3}^-$ were 1.3 and 3.8 times, respectively. From the factor analysis, the TSP compositions were influenced mainly by anthropogenic emission sources, followed by oceanic and soil sources. The backward trajectory analysis has shown that the concentrations of the anthropogenic and soil components were increased when the air parcels had been moved into Jeju island via China in a northwesterly wind.

• Journal of the Korean earth science society
• /
• v.44 no.1
• /
• pp.79-89
• /
• 2023

The purpose of this study was to investigate the effects of engineering design-based ocean cleanup classes on STEAM attitudes and creative engineering problem-solving dispositions. Furthermore, during this process, we tried to determine interesting points that students encountered in engineering design-based classes. For this study, a science class with six lessons based on engineering design was developed and reviewed by a professor who majored in engineering design, along with five engineering design experts with a master's degree or higher. The subject of the class was selected as the design and implementation of scientific and engineering measures to reduce marine pollution based on the method implemented in an actual Ocean Clean-up Project. The engineering design process utilized the engineering design model presented by NGSS (2013), and was configured to experience redesign through the optimization process. To verify effectiveness, the STEAM attitude questionnaire developed by Park et al. (2019) and the creative engineering problemsolving propensity test tool developed by Kang and Nam (2016) were used. A pre and post t-test was used for statistical analysis for the effectiveness test. In addition, the contents of interesting points experienced by the learners were transcribed after receiving descriptive responses, and were analyzed and visualized through degree centrality analysis. Results confirmed that engineering design in science classes had a positive effect on both STEAM attitude and creative engineering problem-solving disposition (p< .05). In addition, as a result of unstructured data analysis, science and engineering knowledge, engineering experience, and cooperation and collaboration appeared as factors in which learners were interested in learning, confirming that engineering experience was the main factor.