• Journal of the Institute of Electronics Engineers of Korea SP
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• v.41 no.5
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• pp.53-62
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• 2004

In this study, an improved post-processing technique for correcting MRI artifact due to the unknown respiratory motion in the imaging plane is presented. Respiratory motion is modeled by a two-Dimensional linear expending-shrinking movement. Assuming that the body tissues are incompressible fluid like materials, the proton density per unit volume of the imaging object is kept constant. According to the introduced model, respiratory motion imposes phase error, non-uniform sampling and amplitude modulation distortions on the acquired MRI data. When the motion parameters are known or can be estimatead a reconstruction algorithm based on biliner superposition method was used to correct the MRI artifact. In the case of motion parameters are unknown, first, the spectrum shift method is applied to find the respiratory fluctuation function, x directional expansion coefficient and x directional expansion center. Next, y directional expansion coefficient and y directional expansion center are estimated by using the minimum energy method. Finally, the validity of this proposed method is shown to be effective by using the simulated motion images.

• Journal of Korean Society of Archives and Records Management
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• v.20 no.3
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• pp.23-37
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• 2020

This paper aims to elaborate on the reality of Gagakgo (架閣庫) by looking into its staff and abolition, given how Gagakgo was originally where diverse archives in Joseon were preserved. This study on Gagakgo, therefore, could be used as a basic reference to grasp the reality of the Joseon's Records Centers and Archives. This institution was changed as a labor organization following changes in the political environment. As a result, the status and operational aspects of the institution also changed. Gagakgo was abolished once during King Sejo (世祖)'s reign and then restored during the period between King Hyojong (孝宗)'s and YoungJo (英祖)'s reign. This restored institution also performed the same role as before. This paper serves as reference to better understand the system of Gagakgo and the archival preservation system in Joseon.

• Journal of Energy Engineering
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• v.8 no.4
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• pp.567-575
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• 1999

This study found potential ability to generate electric power using difference in water temperature between sea surface water and deep water in the East Sea which includes the East Sea Proper Water with the temperature less than 1$^{\circ}C$ throughout a year without seasonal variation. To quantify the difference in water temperature between sea surface water and deep water in the East Sea. We computed the annual mean ($^{\circ}C$), the annual amplitude ($^{\circ}C$), the annual phase (degree) and the duration time which showed more than 15$^{\circ}C$ temperature difference from the water temperature data using Harmonic analysis during 1961~1997. The best place for generating electric power in the East Sea seems to be the eastward ocean areas (36$^{\circ}$ 05'N, 129$^{\circ}$ 48'E~36$^{\circ}$ 05'N, 130$^{\circ}$ 00E'E) from Pohang city. The annual mean of the difference in water temperature between sea surface water and 500 m depth was 24$^{\circ}$C at the place to generate electric power in August according to the data of 1961~1997. the maximum duration periods with more than 15$^{\circ}C$ temperature difference were 215 days (5/5-12/10) a year in the place mentioned electricity with a stable plan. In the East Sea coastal areas of the Korean peninsula, the average minimum depth to reach the East Sea Proper Water from surface water is 300 m and fluctuates between 250 m and 350 m throughout a year. Further studies could be needed for the utilization of cold water, such as the East Sea Proper Water for energy conversion.

• Journal of the Daesoon Academy of Sciences
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• v.36
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• pp.227-266
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• 2020

The purpose of this paper is to review the representative Buddhist policies enforced during the reign of Gwanghaegun (光海君), the 15th king of the Joseon Dynasty, and the aspects of the Buddhist community affected by them. Through this, the influence and dynamism of Buddhism during the reign of Gwanghaegun will be revealed. Some of the findings will run contrary to what is popularly known about Joseon Buddhism and the policy of Sungyueokbul (崇儒抑佛), 'Revering Confucianism and Supressing Buddhism.' During the Joseon Dynasty, Neo-Confucianism was taken as an ideological background, and consequently, Buddhism was ostracized by the ruling class who advocated the exclusion of heretical views. This also characterized King Gwanghaegun's reign during the Mid-Joseon Dynasty. In reality though, the ruling class held mixed opinions about Buddhism, and this influenced the Buddhist community in the Gwanghaegun Period. The military might of Japan demonstrated during the Japanese Invasion of Korea in 1592, led the ruling class to recognize Buddhism, and as a result, the status of Buddhism rose to a certain extent. Based on its elevated status and the aftermath of the Japanese Invasion of Korea, the Buddhist community engaged in social welfare activities inspired by the notion of requiting favors, and the Buddhist community gained recognition for providing relief services. As a result, the number of monks increased, and the economic situation improved as land ownership was granted to temples and monks. This is the means by which the Japanese Invasion of Korea influenced the Buddhist policies of the Gwanghaegun Period and changed the religious topography of Buddhism. During the reign of King Gwanghaegun, the ruling class regarded Buddhism as heretical, but offered posthumous titles to monks who engaged in meritorious services during the Japanese invasions of 1592~1598. Favorable and/or preferential treatment was also granted to some Buddhist monks. In addition, monks began to perform labor projects that demanded organizational and physical strength, such as those which related to national defense and architecture. However, throughout the Gwanghaegun Period, the monks were paid a certain amount of compensation for their labor, and the monks' responsibility for labor increased. This can be understood as a partial reconciliation with Buddhism or an acceptance of Buddhism rather than the suppression of Buddhism often presented by historians. As for policies which affected Buddhism, the Buddhist community showed signs of cooperation with the ruling class, the creation and reconstruction of temples, and the production of Buddhist art. Through close ties with the ruling class, Buddhism during the Gwanghaegun Period saw the Buddhist community actively responded policies that impacted Buddhism, and this allowed their religious orders to be maintained. In this way, it was also confirmed that the monk, Buhyu Seonsu (浮休 善修) and his disciple Byeogam Gakseong (碧巖 覺性), took up leadership roles in their Buddhist community. The Buddhist-aimed policies of Gwanghaegun were implemented against the backdrop of the Buddhist community, wherein the ruling class held mixed opinions regarding Buddhism. As such, both improvements and set backs for Buddhism could be observed during that time period. The ruling class actively utilized the organizational power of Buddhism for national defense and civil engineering after the Japanese invasions of 1592~1598. Out of gratitude, they implemented appropriate compensation for the Buddhists involved. The Buddhist community also responded to policies that affected them through exchanges with the ruling class. They succeeded in securing funds and support to repair and produce Buddhist temples and artworks. A thoughtful inspection of the policies towards and responses to Buddhism during the Gwanghaegun Period, shows that Buddhism actually enjoyed considerable organizational power and influence. This flies in the face of the general description of Joseon Buddhism as "Sungyueokbul (revering Confucianism and supressing Buddhism)."

• The Journal of Korean Society for Radiation Therapy
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• v.22 no.1
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• pp.25-32
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• 2010

Purpose: In radiotherapy that takes into account respiration using a RPM (Real time Position Management, Varian, USA) system, which can treat in consideration of the movement of tumor, infrared reflective markers supplied by manufacturers cannot obtain respiratory signal if the couch rotates at a certain angle or larger. In order to solve this problem, the author developed the 3D infrared reflective marker named 'Kw-marker' that can obtain respiratory signal at any angle, and evaluate its usefulness. Materials and Methods: In order to measure the stability of respiratory signal, we put the infrared reflective marker on the 3D moving phantom that can reproduce respiratory movement and acquired respiratory signal for 3 minutes under each of 3 conditions (A: $couch\;0^{\circ}$, a manufacturer's infrared reflective marker B: $couch\;0^{\circ}$, Kw-marker C: $couch\;90^{\circ}$, Kw-marker). By analyzing the respiratory signal using a breath analysis program (Labview Ver. 7.0), we obtained the peak value, valley value, standard deviation, variation value, and amplitude value. In order to examine the rotation error and moving range of the target, we placed a B.B phantom on the 3D moving phantom, and obtained images at a couch angle of $0^{\circ}$ and $90^{\circ}$ using OBI, and then acquired the X, Y and Z values (mm) of the ball bearing at the center of the B.B phantom. Results: According to the results of analyzing the respiratory signal, the standard deviation at the peak value was A: 0.002, B: 0.002 and C: 0.003, and the stability of respiration for amplitude was A: 0.15%, B: 0.14% and C:0.13%, showing that we could get respiratory signal stably by using the Kw-marker. When the couch rotated $couch\;90^{\circ}$, the mean rotation error of the ball bearing, namely, the target was X: -1.25 mm, Y: -0.45 mm and Z: +0.1 mm, which were within 1.3 mm on the average in all directions, and the difference in the moving range of the target was within 0.3 mm. Conclusion: When we obtained respiratory signal using the Kw-marker in non-coplanar treatment where the couch rotated, we could acquire respiratory signal stably and the Kw-marker was effective enough to substitute for the manufacturer's infrared reflective marker. When the rotation error and moving range of the target were measured, there was little difference, indicating that the displacement of the reflector movement in couch rotation is the cause of change in the scale and amplitude of respiratory signal. If the converted value of amplitude height according to couch angle is studied further and applied, it may be possible to perform non-coplanar phase-based gating treatment.

• Korean Journal of Ecology and Environment
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• v.51 no.1
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• pp.105-123
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• 2018

Currently, satellite images act as essential and important data in water resources, environment, and ecology as well as information of geographic information system. In this paper, we will investigate basic characteristics of satellite images, especially application examples in water resources. In recent years, researches on spatial and temporal characteristics of large-scale regions utilizing the advantages of satellite imagery have been actively conducted for fundamental hydrological components such as evapotranspiration, soil moisture and natural disasters such as drought, flood, and heavy snow. Furthermore, it is possible to analyze temporal and spatial characteristics such as vegetation characteristics, plant production, net primary production, turbidity of water bodies, chlorophyll concentration, and water quality by using various image information utilizing various sensor information of satellites. Korea is planning to launch a satellite for water resources and environment in the near future, so various researches are expected to be activated on this field.

• (The)Study of the Eastern Classic
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• no.37
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• pp.377-410
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• 2009

In the East Asian Confucianism society, Hakmun was aimed to bring human beings and nature into harmony, and to explore a unity between knowledge and conducts. For example, Neo-Confucianism aspired they could explain the human existence and society through a single concept of Iki(理氣, the basic principles and the atmospheric force of nature). In this philosophy, humanics and natural sciences had not been differentiated at all. The East-West cultural interchanges at the beginning of modernity caused a crack in the traditional academic concepts. Through the Hundred Days of Reform(變法自疆運動, a movement of Strenuous Efforts through Reforming the Law), the Western Affairs Movement(洋務運動) in China, Meiji Restoration(明治維新) in Japan, or Innovation Movements(開化運動) and the Patriotic Enlightenment Movement(愛國啓蒙運動) in Korea, the traditional meanings of Hakmun was degraded while it became a target of the criticism of the enlightenment movements. Accordingly, East Asians' perception of Hakmun rapidly began to change. Although there had been the Silhak(實學, practical science) movement in Korea, which tried to differentiate its conceptualization of Hakmun from that of Neo-Confucianism during the 18th and 19th century, the fundamental shift in meaning occurred with the influx of the modern Western culture. This change converted the ultimate objective of Hakmun as well as its methods and substances. The separation of humanics and natural sciences, rise in dignity of the technological sciences, and subdivision of learning into disciplines and their specialization were accelerated during the Korean enlightenment period. The inflow of the modern western science, humanized thought, and empiricism functioned as mediators in these phase and they caused an irreversible crack in the traditional academic thoughts. Confronting the western mode of knowledge, however, the East Asian intellectuals had to explain their new learning by using traditional terms and concepts; modification was unavoidable when they tried to explain the newly imported knowledge and concepts. This presentation focuses on the traditional concepts of 'gyeogchi'(格致, extending knowledge by investigating things) and 'gungni'(窮理, investigation of principles), pervasively used in philosophy, physics and many other fields of study. These concepts will mark the key point with which to trace changes of knowledge and to understand the way how the concept of Hakmun was converted into a modern one.