• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.43 no.1
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• pp.12-27
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• 2007

This fundamental studies on for the productivity improvement and laborsaving of purse seine fishery. Given the difficulty posed from the distortion of net shape caused by the external forces, such as tide, at the time of shooting and pursing, we set the 4 steps of 0, 2, 4 and 6cm/sec in flow velocity in the flume tank for the experiment in order to examine those characteristics. We used two model seines designed on the scale of 1 to 180 based on the power block seine, which is the mackerel purse seine generally used in the near sea of Jeju Island and triplex seine, which is the mackerel purse seine of one boat system fishing expected in the future, for the experiment, and interpreted the characteristics of several motion in water, such as the shape of seine, the change in tension and area during pursing and its the analysis results are as follows. Though the experiment could be conducted up to 6cm/sec of flow velocity that was defined, the experiment could not go on because of the severe distortion in the seine at the flow velocity in excess of 6cm/sec. As for the depth of leadline and reduction rate of side area of seine when the pursing is connected, P seine turned out to be slightly higher than T seine, and the hauling speed and reduction rate of upper area of seine were found similar to each other. The correlation between the hauling time (Ht) and depth of lead line (Dhp, Dht) of P seine and T seine can be expressed by the equation, that is, Dhp=(0.99Pt-7.63)Pt+69.01, Dht=(1.03Pt-7.73)Pt+66.74. The correlation between the hauling time and hauling velocity (Hpp, Hpt) can be expressed by the equation, that is, $Hpp=-0.06Ht^2+0.88Ht+0.78,\;Hpt=-0.05Ht^2+0.81Ht+0.98$ here, Pt is pursing time. And the correlation between the pursing time and the reduction rate of side area (sArp, sArt) can be expressed by the equation, that is, $sArp=-0.48Pt^2+14.79Pt-16.74,\;sArt=-0.45Pt^2+14.56Pt-16.48$. The reduction rate of upper area of seine (tArp, tArt) can be expressed by the equation, that is, $tArp=0.34Pt^2-0.66Pt-0.74,\;tArt=0.34Pt^2-0.27Pt-1.80$. In addition, the correlation between the pursing time and tension of purse line (Tep, Tet) can be expressed by the equation, that is, $Tep=2.79Pt^2+2.26Pt-0.60,\;Tet=2.14Pt^2+8.08Pt-27.50$.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.3
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• pp.16-22
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• 2019

Off-line programming and robot calibration through simulation are essential when setting up a robot in a robot automation production line. In this study, we developed a new robot calibration method to match the CAD data of the production line with the measurement data on the site using 3D scanner. The proposed method calibrates the robot using 3D point cloud data through Iterative Closest Point algorithm. Registration is performed in three steps. First, vertices connected by three planes are extracted from CAD data as feature points for registration. Three planes are reconstructed from the scan point data located around the extracted feature points to generate corresponding feature points. Finally, the transformation matrix is calculated by minimizing the distance between the feature points extracted through the ICP algorithm. As a result of applying the software to the automobile welding robot installation, the proposed method can calibrate the required accuracy to within 1.5mm and effectively shorten the set-up time, which took 5 hours per robot unit, to within 40 minutes. By using the developed system, it is possible to shorten the OLP working time of the car body assembly line, shorten the precision teaching time of the robot, improve the quality of the produced product and minimize the defect rate.

• Journal of Radiation Industry
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• v.12 no.4
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• pp.325-332
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• 2018

Carotid angiography covering the aortic arch includes contrast-enhanced magnetic resonance angiography (CEA), which is applied to a large region and usually employs contrast media. However, the use of contrast media can be dangerous in infants, pregnant women, and patients with chronic renal failure (CRF). Follow-up patients informed of a lesion may also want to avoid constant exposure to contrast media. We aimed to apply time-of-flight (TOF) angiography to a large region and compare its usefulness with that of CEA. Ten patients (mean age, 58 years; range, 45~75 years) who visited our hospital for magnetic resonance angiography (MRA) participated in this study. A 3.0 Tesla Achieva magnetic resonance imaging (MRI) system (Philips, Netherland) and the SENSE NeuroVascular 16-channel coil were employed for both methods. Both methods were applied simultaneously to the same patient. Three TOF stacks were connected to cover the aortic arch through the circle of Willis, and CEA was applied in the same manner. For the quantitative assessment, the acquired images were used to set the regions of interest (ROIs) in the common carotid artery (CCA) bifurcation, internal carotid artery, external carotid artery, middle cerebral artery, and vertebral artery, and to obtain the signal-to-noise ratio (SNR) and the contrast-to-noise ratio (CNR) for the soft tissues. Three radiologists and one radiological resident performed the qualitative assessment on a 5-point scale - 1 point, "very bad"; 2 points, "bad"; 3 points, "average"; 4 points, "good"; and 5 points, "very good" - with regard to 4 items: (1) sharpness, (2) distortion, (3) vein contamination, and (4) expression of peripheral vessels. For the quantitative assessment, we estimated the mean SNR and CNR in each of the 5 ROIs. In general, the mean SNR was higher in TOF angiography (166.1, 205.2, 154.39, 172.23, and 161.95) than in CEA(92.05, 95.43, 84.76, 73.69, and 88.3). Both methods had a similar mean CNR: 67.62, 106.71, 55.9, 73.74, and 63.46 for TOF angiography, and 67.82, 71.19, 60.52, 49.45, and 64.07 for CEA. In all ROIs, the mean SNR was statistically significant (p<0.05), whereas the mean CNR was insignificant (p>0.05). The mean values of TOF angiography and CEA for each item in the qualitative assessment were 4.2 and 4.28, respectively for item 1; 2.93 and 4.55, respectively, for item 2; 4.6 and 3.13, respectively, for item 3; and 2.88 and 4.65, respectively, for item 4. Therefore, TOF angiography had a higher mean for item 3, and CEA had a higher mean for items 2 and 4; there was no significant difference between the two methods for item 1. The results for item 1 were statistically insignificant (p>0.05), whereas the results for items 2~4 were statistically significant (p<0.05). Both methods have advantages and disadvantages and they complement each other. However, CEA is usually applied to a large region covering the aortic arch. Time-of-flight angiography may be useful for people such as infants, pregnant women, CRF patients, and followup patients for whom the use of contrast media can be dangerous or unnecessary, depending on the circumstance.

• Fire Science and Engineering
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• v.32 no.6
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• pp.34-39
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• 2018

In this paper, the architecture of a safe stove with an automatic fire suppression function using a sound wave fire extinguisher has been proposed and developed for the first time. A microcontroller connected to a fire sensor detects and suppresses a fire by driving a fire extinguisher. The sound wave fire extinguisher is composed of a speaker and collimator, and is driven by a driver module including an audio amplifier. The attenuation of the sound wave is reduced by preventing the sound diffusion with an enclosure surrounding a stove. The frequency of the sound wave is set to 50 Hz, and the sound pressure of 93 dBA is measured at the distance of 0.5 m. It takes maximum 8 and 15 seconds to suppress the flame from 7-cc and 14-cc flammable liquid, respectively, which corresponds to 24% and 42% of the natural extinguishing time. Since the proposed safe stove is non-toxic and leaves no residues over the conventional ones, it would combine with various home appliances to suppress early-stage fires and prevent fire expansion.

• Korean Journal of Heritage: History & Science
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• v.52 no.2
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• pp.106-121
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• 2019

Sustainable development in society has become the center of focus in many fields such as industry, environment, health, culture, etc. Considering that the concept of heritage involves understanding it as a 'resource' to improve the quality of people's lives, sustainability is an important goal that heritage policy has to achieve. Adopting the definition of sustainability in the 1987 Brundtland Report, this paper defines the concept of sustainability with respect to heritage, as well as their respective roles. Following that, three action principles are presented: value-based conservation, rational decision-making, and community involvement. Two cases demonstrating how the three principles should be practiced in managing change are then illustrated. Considering that heritage can play its role as a resource once its significance is protected, this paper argues that value-based rational decision-making is of paramount importance and the first principle. Conservation aims to manage change by practicing a cyclic process of value identification, value sustaining, and value dissemination. Therefore, this paper argues that all processes should be connected in the context of heritage values. A rational decision-making process practicing value-based conservation is then suggested. This paper argues that rational decision-making can only be practiced once values are identified by objective criteria and managed by rational judgment upon impact assessment. Community involvement, the third principle, is necessary to realize value-based conservation and rational decision-making. Recognizing that a community is a beneficiary of heritage and a creator of a beneficial process at the same time, it discusses the role of community and the importance of this role in policies for the sustainability of heritage. This paper concludes with a set of recommendations to improve policies after examining the two decision-making cases.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.25 no.10
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• pp.1409-1415
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• 2021

The Gysel divider has the advantage of easily setting the resistor in the circuit. If the line impedance in the Gysel divider is set differently, the input signal can be distributed to the two output ports at various distribution ratios. This paper proposes the Gysel divider that can change the power distribution to 1:3 or 3:1 by changing the line impedance. The impedance change of the line can be implemented by placing a floating copper plate on the bottom of the microstrip-line. When the floating copper plate and the ground plane are connected, the line operates as the microstrip-line, and when the floating copper plate and the ground plane are disconnected, the line operates as the coplanar-line. The proposed Gysel divider was fabricated at the center frequency of 1.5GHz. The fabricated 3:1 Gysel divider has a stable value S₁₁ of below -17dB, S₂₁/S₃₁ of 4.8±0.2dB, S₂₁(to high output port) of -1.39±0.12dB and S₃₁(to low output port) of -6.15±0.08dB over 1.3~1.7GHz.

• The Korean Journal of Archival Studies
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• no.67
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• pp.5-55
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• 2021

The purpose of this study is to promote future research and practical application in the field of records systems by informing the revision of the ISO 16175 standard set and analyzing its main contents, which was widely used as a record management functional requirements. Based on the experience of participating in the developing process of this International Standard since 2015, this study analyzed the context and process of revision, and the main contents of the standard, and sought to draw limited implications and proposed follow-up researches connected to the practice of the Korean records systems. The previous ISO 16175 sets had been produced as ISO 16175-1, 2, 3 in 2010-2011, and which were restructured and revised into new ISO 16175-1, 2 in 2020 in line with the revision of ISO 15489 and changes in the digital environment. Main title of the International Standard is processes and functional requirements for software for managing records, and Part I provides high-level functional requirements and associated guidance for applications that manage digital records, Part II provides guidance for selecting, designing, implementing and maintaining software for managing records. This standard assumes that the records system does not necessarily have to be a single system or software solely for records management and that it should be able to perform record management function in any forms.

• Journal of the Korean Institute of Traditional Landscape Architecture
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• v.29 no.4
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• pp.98-110
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• 2011

Seochon('West Village') is located in the west side of Gyeongbokgung(Gyeongbok Royal Palace) inside the old city wall of Seoul. Seochon has beautiful scenic view surrounding Mt. Inwang and has been known as the representative historical and cultural landscape region in Korea that historical and cultural resources are rich. But when the figure of Seochon which has repeated the changes with the ones of the times is considered, values of beauty of natural landscape that Seochon had and its own placeness have not been gradually recognized as it has been swept away in logic of the development on the strength of economics. This study tries to examine the original form of landscape on Seochon which can be the standard of landscape change, the causes and process of its change and possibility to conserve and restore it to recognize potential value about historical culture of Seochon landscape and conserve and protect it. For this, this study compared and analyzed literature including poems and Yusangi, paintings and names of the scenery of the seasons as the landscape texts with the current status. The study result has found that Pilwundae should rehabilitate cultural assets to secure the prospect right and protect neighboring bedrock, Suseong-dong should expand the restoration areas focusing on the projects to make parks which are now being restored, Cheonghwigak and Cheongpunggye areas should restore waterways including historicity which is connected to figures and Seshimdae and Baekun-dong green zone should set the protective area for conservation.

• The Journal of Korean Philosophical History
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• no.32
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• pp.161-183
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• 2011

Lee Ik(李瀷) had put emphasis on the achievements by self-regulated academic learning through doubts, and at the same time that it was all-embracing. His academic attitude had set an example among the members of Seongho school(星湖學派), and his disciples had strived to emulate his style. The greatness of Seongho(星湖)'s study had been revealed by development of Seongho school(星湖學派) right after his death. He had argued that the six strokes of I-Ching should be read having it divided into inward and outward divine signs. He had stated his view clearly that the divine signs ranging from one stroke to six strokes were not connected, same as Shao yong(邵雍)'s method, but, the three strokes of inward divine sign as well as the three strokes of outward divine signs were independent from each other. Seongho(星湖) also had raised many questions about Shifa(筮法), and Bianyao(變爻) and Zhuzi(朱子)'s Shifa(筮法), or Yixueqimeng("易學啓蒙") "Kaobianzhan("考變占")". In view of the Shifa(筮法), Seongho(星湖) had helped Dasan(茶山) to present 'Shiguafa(蓍卦法)' by proposing different divination rule from Zhuzi(朱子)'s Method of Divination by Shiyi("筮儀"). Seongho(星湖) had not professed something significantly different from Zhuzi(朱子) in his I-xue. His study on I-xue had been accomplished under his goal of achievements by self-regulated academic learning through doubts. "Shiguakao("蓍卦攷")" is also same. I-xue of Seongho(星湖) had made a great contribution to form Dasan(茶山)'s I-xue in the later years.

• The Journal of Korean Philosophical History
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• no.41
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• pp.71-92
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• 2014

A series of the tragic 16th-century Sahwas sent Toegye into the depths of despair. In the face of the ensuing social disruption in which any criterion or direction is utterly lost, he could not but to reexamine the problem of human nature and good and evil. For Toegye, criterion or direction is connected with Principle, and human nature and the problem of good and evil are related with Mind. In other words, these problems are none other than the question: "As the subject of history and society, how a human being can set principle in a real world and realize it? How one can successfully control his wants and feelings with his rationality?" Toegye proposes that while laws and regulations should be reformed when they are outdated, good laws and regulations are not necessarily to be discarded. He also warns that ideal governance is not likely to be realized if only too conservatives take the lead while radicals, depended upon exclusively, would create too many problems.