• The Journal of Korea Robotics Society
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• v.17 no.4
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• pp.438-446
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• 2022

In this paper, we propose an intelligent three-legged landing system that can maintain stability and level even on rough terrain than conventional four-legged landing systems. Conventional landing gear has the limitation that it requires flat terrain for landing. The 3-leg landing system proposed in this paper extends the usable range of the legs and reduces the weight, allowing the quadcopter to operate in various environments. To do this, kinematics determine the joint angles and coordinates of the legs of the two-link structure. Based on the angle value of the quadcopter detected via the IMU sensor, the leg control method that corrects the posture is determined. A force sensor attached to the end of the leg is used to detect contact with the ground. At the moment of contact with the ground, landing control starts according to the value of the IMU sensor. The proposed system verifies its reliability in various environments through an indoor landing test stand. Finally, in an outdoor environment, the quadcopter lands on a 20 degree incline and 20 cm rough terrain after flight. This demonstrates the stability and effectiveness of the 3-leg landing system even on rough terrain compared to the 4-leg landing system.

• The Korean Journal of Mycology
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• v.45 no.3
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• pp.246-250
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• 2017

Sclerotium rot was observed on mungbean (Phaseolus radiatus L.) plants cultivated in the exhibition field of Gyeongsangnam-do Agricultural Research and Extension Services in September 2015. The progression of rot was initially observed as water-soaked lesions on several parts of the affected plant. Severely infected plants were blighted and eventually died. White mycelial mats spread over the lesions and numerous sclerotia formed on stems near the soil line. The sclerotia were globoid in shape, 1~3 mm in size, and white to brown in color. The optimum temperature for mycelial growth and sclerotia formation on potato dextrose agar (PDA) was $30^{\circ}C$ and the hyphal width was $4{\sim}8{\mu}m$. Typical clamp connections were observed on the hyphae of fungus grown on PDA. For molecular identification, the complete internal transcribed spacer (ITS) ribosomal DNA (rDNA) of the causal fungus was sequenced and analyzed. Based on the mycological characteristics, ITS rDNA sequence analysis, and pathogenicity to host plants, the fungus was identified as Sclerotium rolfsii. This is the first report of Sclerotium rot on mungbean caused by S. rolfsii in Korea.

• Journal of the Korean Geographical Society
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• v.40 no.4 s.109
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• pp.416-427
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• 2005

This paper aims to investigate morphological changes of deltaic barrier islands in the Nakdong Estuary and especially their spatial variations after barrage construction. We analyzed shorelines, geometrical centroids, and areas to reveal the changes of barrier islands. Here, we suggest three interesting points from this study. First, each individual barrier island in the Nakdong estuary goes through a different stage of the geomorphic cycle. The frontal barrier islands such as Sinja-do and Doyo-deung grow because they are located in front of the gates of the barrage. Sediments in water out of the gates are moved to offshore and then reworked by coastal processes such as waves and tides. Second, on the contrary, Baekhap-deung located behind Doyo-deung now diminishes indicating that sediments mainly move to the frontal growing island. Third, there is no morphological change in several barrier islands far away from the main flow of the Nakdong river such as Jinwoo-do, Daema-deung, and Jangja-do. In conclusion, barrier islands in the Nakdong estuary show distinct spatial variations. As a barrier island is closer to the main channel or is in the frontal location, there happens a very dynamic change in the morphology of the island.

• Korean Journal of Computational Design and Engineering
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• v.19 no.2
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• pp.138-147
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• 2014

In manufacturing companies, different types of production have been developed based on diverse production strategies and differentiated technologies. The production systems have become smart, factories are filled with unmanned manufacturing lines, and sustainable manufacturing technologies are under development. Nowadays, the digital manufacturing technology is being adopted and used in manufacturing industries. When this technology is applied, a lot of efforts, time and cost are required and training professionals in-house is limited. In this paper, we introduce e-FEED system (electronic based Front End Engineering and Design) that is the integrated design and analysis system for optimized manufacturing line development on virtual environment. This system provides the functions that can be designed easily using library and template based on standardized modules and analyzed automatically the logistic and capacity simulation by one-click and verified the result using visual reports. Also, we can review the factory layout using automatically created 3D virtual factory and increase the knowledge reuse by e-FEED system.

• Journal of the Semiconductor & Display Technology
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• v.15 no.4
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• pp.27-32
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• 2016

In recent years, various researches have been conducted to improve process yields in accordance with miniaturization of semiconductor. APC(Advanced Process Control) is considered one of the methods to increase in process yields. APC is a process control technology that maintains optimal process conditions and improves the reliability of results by controlling and formulating the relationship among the various process parameters and results. We built up an optical diagnostic system with a three-channel spectrometer. The system detects signals those represent the changes of specific emission peaks intensity versus each reference and converts it into MFC control signals to get back the changes to the reference state. Controlling the MFC continues until the specific peak intensity changes into the normal state. Through this device, we tested a APC automatically responding to process changes during the plasma process. We could control gas flow while sputtering process on going and improve uniformity of plasma intensity with this system. Finally, we have got results those enhance the plasma intensity non-uniformity to 7.7% from 15.5%. Also, found unexpected oxygen flow what is estimated to be come out from IGZO target.

• The Journal of Bigdata
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• v.3 no.2
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• pp.51-57
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• 2018

The purpose of this study is to find a valid link between color and tourism experience. We analyzed color that extracted by Aerial photo by IRI Image Scale to find color image. As an indicator of the experience of tourism, a review of the Tripadvisor was selected and analyzed through text mining. Results using text mining results and IRI image scales were generally inconsistent. To identify problems with aerial photo, the results of the analysis using the representative photographs provided by the Tripadvisor in the same way were the same as before. This indicate that details are key of tourism than the image of the overall background. This study presents new research directions by combining color analysis studies with text mining.

• Food Science and Preservation
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• v.30 no.6
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• pp.929-943
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• 2023

This study analyzed the variation in vitamin K content in conger eel (Conger myriaster) caught off Tongyeong, Gyeongsangnam-do, Korea, focusing on the influence of size (large and small) and harvest period (monthly throughout 2021). We applied enzymatic extraction and HPLC-fluorescence methods for the analysis of vitamin K₁ (phylloquinone) and K₂ (menaquinone). The vitamin K content in conger eel varied significantly with size and harvest season (p<0.05). In large-sized samples, the phylloquinone content peaked in July (0.80±0.09 ㎍/100 g), while the highest menaquinone content was in May (0.79±0.11 ㎍/100 g). Conversely, in small-sized conger eels, the highest phylloquinone was found in December (1.94±0.15 ㎍/100 g), and the peak menaquinone level was in January (0.66±0.02 ㎍/100 g). The fat content was highest in July for large samples and in January for smaller ones. There was a positive correlation between fat and total vitamin K contents in conger eel (r=0.631, 0.667). Method validation and quality control measures ensured data reliability for vitamin K₁ and K₂ analyses. This study provides reliable information on the size and seasonal variations of vitamin K in conger eels, a staple in the Korean diet. This information is valuable for inclusion in Korea's national food nutrition database and for formulating future national health and nutrition policies.

• Journal of KIISE:Computing Practices and Letters
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• v.11 no.3
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• pp.235-245
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• 2005

The rapid development of computer network technology has brought the Internet as the major infrastructure to our society. But the rapid increase in malicious computer intrusions using such technology causes urgent problems of protecting our information society. The recent trends of the intrusions reflect that the intruders do not break into victim host directly and do some malicious behaviors. Rather, they tend to use some automated intrusion tools to penetrate systems. Most of the unknown types of the intrusions are caused by using such tools, with some minor modifications. These tools are mostly similar to the Previous ones, and the results of using such tools remain the same as in common patterns. In this paper, we are describing design and implementation of attacker-traceback system, which traces the intruder based on the multi-agent architecture. The system first applied SOM to classify the unknown types of the intrusion into previous similar intrusion classes. And during the intrusion analysis stage, we formalized the patterns of the tools as a knowledge base. Based on the patterns, the agent system gets activated, and the automatic tracing of the intrusion routes begins through the previous attacked host, by finding some intrusion evidences on the attacked system.

• The Bulletin of The Korean Astronomical Society
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• v.41 no.1
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• pp.63.4-64
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• 2016

본 발표에서는 DSLR 카메라와 CCD를 이용하여 과학고등학교의 R&E교육과정에서 수행한 몇 가지 실험과 그 결과를 소개한다. DSLR 카메라와 SQM을 이용한 밤하늘 특성 분석, CCD를 이용한 고유운동 측정, DSLR을 이용한 산개성단의 측광, CCD를 이용한 산개성단의 측광과 이를 통한 산개성단의 질량분리와 역학적 진화에 대한 연구이다. 실험은 부산일과학고, 울산과학고, 부산과학고에서 수행되었으며, 모든 실험의 결과는 학생들이 직접 관측한 결과를 바탕으로 이루어졌다. 본 실험의 방법과 과정은 일선 학교에서 응용하여 활용될 수 있으며, 실험의 결과는 향후 유사한 실험 교육을 수행할 때 기초 자료로 활용되어 질 수 있다.

• Journal of Marine Life Science
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• v.5 no.2
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• pp.81-91
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• 2020

This study was conducted to find the faunal composition and distribution patterns of macrobenthos where the sand tidal flat around barrier island at Nakdong River estuary in May, 2016 and 2017. The number of species ranged from 31 to 39, and density was from 789 to 1,644 ind.m^-2 during the study period in the three tidal flats. The number of species and density were the highest in the tidal flat of Shinja-do and Jinwoo-do, respectively. The dominant species were Gammaridae unid. in amphipods of crustacea, Scoletoma heteropoda, Scoloplos armiger, Heteromastus filiformis, Prionospio japonica in polychaeta and Batillaria cumingii, Laternula marilina in mollusks from the three tidal flats. The proportion of carnivores such as crustacea and mollusks was higher in the upper part of the tidal flat, and polychaetes of deposit feeders, dominated in the middle and lower tidal flat. Overall, the intertidal macrobenthic communities in the study area showed a high proportion of carnivores. However, the sites where the mud content is high such as muddy sand sites, they showed a higher proportion of surface deposit feeders belonging to tube-builders which contribute to sediment stability. From this study, it seemed that the macrobenthic fauna of the sandy tidal flat at the Nakdong River estuary showed a similar fauna composition and zonal distribution patterns from those in other sandy tidal flats in Korea.