• The Korean Journal of Nuclear Medicine
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• v.39 no.1
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• pp.57-68
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• 2005

Purpose: The objective of this study was to assess attenuation correction algorithms with the $^{137}Cs$ point source for the brain positron omission tomography (PET) imaging process. Materials & Methods: Four different types of phantoms were used in this study for testing various types of the attenuation correction techniques. Transmission data of a $^{137}Cs$ point source were acquired after infusing the emission source into phantoms and then the emission data were subsequently acquired in 3D acquisition mode. Scatter corrections were performed with a background tail-fitting algorithm. Emission data were then reconstructed using iterative reconstruction method with a measured (MAC), elliptical (ELAC), segmented (SAC) and remapping (RAC) attenuation correction, respectively. Reconstructed images were then both qualitatively and quantitatively assessed. In addition, reconstructed images of a normal subject were assessed by nuclear medicine physicians. Subtracted images were also compared. Results: ELEC, SAC, and RAC provided a uniform phantom image with less noise for a cylindrical phantom. In contrast, a decrease in intensity at the central portion of the attenuation map was noticed at the result of the MAC. Reconstructed images of Jaszack and Hoffan phantoms presented better quality with RAC and SAC. The attenuation of a skull on images of the normal subject was clearly noticed and the attenuation correction without considering the attenuation of the skull resulted in artificial defects on images of the brain. Conclusion: the complicated and improved attenuation correction methods were needed to obtain the better accuracy of the quantitative brain PET images.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.14 no.7
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• pp.586-603
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• 2004

One of the subtle problems that make noise control difficult for engineers is “the invisibility of noise or sound.” The visual image of noise often helps to determine an appropriate means for noise control. There have been many attempts to fulfill this rather challenging objective. Theoretical or numerical means to visualize the sound field have been attempted and as a result, a great deal of progress has been accomplished, for example in the field of visualization of turbulent noise. However, most of the numerical methods are not quite ready to be applied practically to noise control issues. In the meantime, fast progress has made it possible instrumentally by using multiple microphones and fast signal processing systems, although these systems are not perfect but are useful. The state of the art system is recently available but still has many problematic issues : for example, how we can implement the visualized noise field. The constructed noise or sound picture always consists of bias and random errors, and consequently it is often difficult to determine the origin of the noise and the spatial shape of noise, as highlighted in the title. The first part of this paper introduces a brief history, which is associated with “sound visualization,” from Leonardo da Vinci's famous drawing on vortex street (Fig. 1) to modern acoustic holography and what has been accomplished by a line or surface array. The second part introduces the difficulties and the recent studies. These include de-Dopplerization and do-reverberation methods. The former is essential for visualizing a moving noise source, such as cars or trains. The latter relates to what produces noise in a room or closed space. Another mar issue associated this sound/noise visualization is whether or not Ivecan distinguish mutual dependence of noise in space : for example, we are asked to answer the question, “Can we see two birds singing or one bird with two beaks?"

• Asian Journal of Turfgrass Science
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• v.23 no.2
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• pp.219-228
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• 2009

The construction procedures and artificial turf maintenance program on golf course definitely influence on the distortion of its environment. Soil microbial communities in soil profile were affected directly by those practises on turf areas. In Jeju island, the environmental impact assessment has been required to apply the first quality class granular activated carbon(GAC), which has a high absorbent character to agricultural chemicals, on the soil profiles of golf green system to reduce the pesticide leaching to ground water. This research was carried out to analyze the changes of microbial communities and chemical properties on soil profiles where GAC had been applied at the construction stage at two golf courses in Jeju. The changes of soil microbial population and chemical properties associated with construction methods of soil profile and agrochemical management program were analyzed by monthly at the surface and sub-soil profiles during April through October, 2007. The total numbers of bacteria and fungi, soil moisture content, soil physio-chemical properties were measured on greens and fairways of the both golf courses with different GAC treatment on the green and fairway soil profiles. The results showed that GAC had positive effects on the water holding capacity, pH and EC, however, it did not improved the holding capacity of available nutrients ${NO_3}^-,{NH_4}^+$, and phosphorus by its sorption phenomenon. In microbial count test, the total numbers of bacteria and fungi showed a great variation during sampling dates. That may directly relate to the agrochemical application, however, the ratio of total bacterial number versus total fungus number showed a constant value on a sub-soil of 15~30cm depth. Thus, the construction method of GAC in soil profile, and application of fertilizer and pesticide, both impacted on the changes of microbial population. It's means that the construction method of soil profile and turf management using agro-materials might greatly affect on the turfgrass culture and the environment of golf course.

• Journal of Bio-Environment Control
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• v.30 no.4
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• pp.271-277
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• 2021

In this study, experiments of local heating on crown and supplying warm nutrient for energy saving and improving growth of 'Seolhyang' strawberry were conducted. The temperature of inside and crown in greenhouses which were control (space heating 8℃) and test (space heating 5℃+crown heating) was measured. In the control greenhouse, the average of temperature and humidity in December was 7.1℃, 87.2%, respectively. In the test greenhouse, the average of temperature and humidity in December was 5.7℃, 88.7%. The temperature of crown and inside the bed were 7.9℃, 10.8℃ in control, 9.3℃, 12.7℃ in test. During the test period, the total 16,847×10³ kcal of energy was consumed in control greenhouse including space heating. In test greenhouse including space heating, crown heating and warm water supplying, total 9,475.7×10³ kcal of energy was consumed. So, energy consumption in test was 43.8% less than in the control. The total yields of strawberry during test period were 412.7g/plant for test greenhouse and 393.3g/plant for control greenhouse respectively.

• Sleep Medicine and Psychophysiology
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• v.26 no.1
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• pp.44-48
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• 2019

Objectives: Insomnia is one of the most prevalent sleep disorders. Recent studies suggest that cognitive and physical arousal play an important role in the generation of primary insomnia. Studies have also shown that information processing disorders due to cortical hyperactivity might interfere with normal sleep onset and sleep continuity. Therefore, focusing on central nervous system arousal and normalizing the information process have become current topics of interest. It has been well known that neurofeedback can reduce the brain hyperarousal by modulating patients' brain waves during a sequence of behavior therapy. The purpose of this study was to investigate effects of neurofeedback therapy on electroencephalography (EEG) characteristics in patients with primary insomnia. Methods: Thirteen subjects who met the criteria for an insomnia diagnosis and 14 control subjects who were matched on sex and age were included. Neurofeedback and sham treatments were performed in a random order for 30 minutes, respectively. EEG spectral power analyses were performed to quantify effects of the neurofeedback therapy on brain wave forms. Results: In patients with primary insomnia, relative spectral theta and sigma power during a therapeutic neurofeedback session were significantly lower than during a sham session ($13.9{\pm}2.6$ vs. $12.2{\pm}3.8$ and $3.6{\pm}0.9$ vs. $3.2{\pm}1.0$ in %, respectively; p < 0.05). There were no statistically significant changes in other EEG spectral bands. Conclusion: For the first time in Korea, EEG spectral power in the theta band was found to increase when a neurofeedback session was applied to patients with insomnia. This outcome might provide some insight into new interventions for improving sleep onset. However, the treatment response of insomniacs was not precisely evaluated due to limitations of the current pilot study, which requires follow-up studies with larger samples in the future.

• Korean Journal of Heritage: History & Science
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• v.52 no.1
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• pp.120-147
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• 2019

In this study, we divided the portraits in the reign of King Seonjo into those which were created before and after the Japanese invasion. We then examined various aspect of costumes expressed in the portraits of meritorious vassals. To analyze official uniforms (Heuk-Danryeung), we examined the Samo height; the side wings' type and pattern; the Danryeung pattern; the Mu style; the processing method of lateral lines in Danryeung the rank badge and rank belt, the color of Dabho and Cheolrik, which were undergarment of Danryeung and Heuk-wa. The meritorious vassals' portraits, prior to Imran, were analyzed with a portrait of Han Eung-in, a Gwang-kuk Pyeong-nan meritorious vassals. The Samo was the highest of the Choson dynasties, and the cloud and treasure pattern was identified on the side wings. The Heuk-Danryeung was a dark blue(acheongsaeg) Danryeung of manja-shaped cloud patterns with a large outward wrinkled Mu, and it had a wild goose badge (second rank) and a Sabgeumdae. It did not coincide with the Pumgye(Jaheondaebu) recorded in Gugjo-inmulgo. Reddish Dabho for Dangsang-kwan, green Cheolrik which was undergarment of Danryeung, and Heuk-wa. were identified. After the invasion of Japan, portraits of Hoseong, Seonmu, and Cheong-nan meritorious vassals were analyzed through eighteen portraits, including Lee Hyeon-bok. After the invasion of the Japanese, the height of the Samo's top was much lower and the width of the side wings was wider than before the invasion of Japanese. The Heuk-Danryeung was a dark blue (acheongsaeg) Danryeung of manja-shaped cloud patterns with a stretching backward Mu. Rank badge and rank belts were almost identical with the record, but there were two exceptions (Sin-jab and Kim, Sae-sin). Therefore, it was reaffirmed that the meritorious vassals' portraits were drawn by the Pumgye at the time of appointment. Among the undergarments of Heuk-Danryeung, green Dabho(11), blue Dabho(4), reddish Dabho(3), and blue Cheolrik(10), green Cheolrik(6), reddish Cheolrik(1), and yucheongsaeg Cheolrik(1) were identified, However, it is suggested that the Dabho of Hoseong, Seonmu, and Cheong-nan meritorious vassals should be the reddish Dabho of Dangsang-kwan, which is the same as the previous Imran, and a green Cheolrik.

• Journal of the Korean Association of Geographic Information Studies
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• v.21 no.4
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• pp.64-80
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• 2018

In Korea, citizens can only know general information about crime. Thus it is difficult to know how much they are exposed to crime. If the police can predict the crime risky area, it will be possible to cope with the crime efficiently even though insufficient police and enforcement resources. However, there is no prediction system in Korea and the related researches are very much poor. From these backgrounds, the final goal of this study is to develop an automated crime prediction system. However, for the first step, we build a big data set which consists of local real crime information and urban physical or non-physical data. Then, we developed a crime prediction model through machine learning method. Finally, we assumed several possible scenarios and calculated the probability of crime and visualized the results in a map so as to increase the people's understanding. Among the factors affecting the crime occurrence revealed in previous and case studies, data was processed in the form of a big data for machine learning: real crime information, weather information (temperature, rainfall, wind speed, humidity, sunshine, insolation, snowfall, cloud cover) and local information (average building coverage, average floor area ratio, average building height, number of buildings, average appraised land value, average area of residential building, average number of ground floor). Among the supervised machine learning algorithms, the decision tree model, the random forest model, and the SVM model, which are known to be powerful and accurate in various fields were utilized to construct crime prevention model. As a result, decision tree model with the lowest RMSE was selected as an optimal prediction model. Based on this model, several scenarios were set for theft and violence cases which are the most frequent in the case city J, and the probability of crime was estimated by $250{\times}250m$ grid. As a result, we could find that the high crime risky area is occurring in three patterns in case city J. The probability of crime was divided into three classes and visualized in map by $250{\times}250m$ grid. Finally, we could develop a crime prediction model using machine learning algorithm and visualized the crime risky areas in a map which can recalculate the model and visualize the result simultaneously as time and urban conditions change.

• The Korean Journal of Archival Studies
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• no.38
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• pp.75-124
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• 2013

This study aims, by paying attention to the special values of records of Constitutional Court, to discuss the characteristics of them and figuring out their present state, and to suggest some measures for improvement in the records management. First of all, I defined the concept of the records of Constitutional Court and its scope, and made an effort to comprehend their types and distinct features, and on the basis of which I tried to grasp the characteristics of the records. Put simply, the records of Constitutional Court are essential records indispensible to the application of Constitutional Court's documentation strategy of them, and they are valuable particularly at the level of the taking-root of democracy and the guarantee of human rights in a country. Owing to their characteristics of handling nationally important events, also, the context of the records is far-reaching to the records of other constitutional institutions and administrations, etc. In the second place, I analyzed Records Management Present State. At a division stage, I grasped the present state of creation, registration, and classification system of records. At an archives repository stage, I made efforts to figure out specifically the perseveration of records and the present of state of using them. On the basis of such figuring-outs of the present situation of records of Constitutional Court, I pointed at problems in how to manage them and suggested some measures to improve it in accordance with the problems, by dividing its process into four, Infrastructure, Process, Opening to the public and Application. In the infrastructure process, after revealing problems in its system, facilities, and human power, I presented some ways to improve it. In terms of its process, by focusing on classification and appraisal, I pointed out problems in them and suggested alternatives. In classification, I suggested to change the classification structure of trial records; in appraisal, I insisted on reconsidering the method of appropriating the retention periods of administration records, for it is not correspondent with reality in which, even in an file of a event, there are several different retention periods so it is likely for the context of the event worryingly to be segmented. In opening to the public and application, I pointed at problems in information disclosure at first, and made a suggestion of the establishment of a wide information disclosure law applicable to all sort of records. In application, I contended the expansion of the possibility of application of records and the scope of them through cooperation with other related-institutions.

• Journal of Bio-Environment Control
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• v.28 no.4
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• pp.293-301
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• 2019

The experiment was conducted to determine the performance of DME combustion gas when used as a fuel for DME burner for raising temperature and $CO_2$ concentration in greenhouse and also to examine its effects on chlorophyll content, and fresh and dry weight of lettuce and Chinese cabbage. DME-1 and DME-2 treatments consisted of average DME flow quantity in duct were $17.4m^3min^{-1}$ and $10.2m^3min^{-1}$ respectively to greenhouse-1 and greenhouse-2 and no DME gas was supplied to greenhouse-3 which was left as control (DME-3). DME supply times were $0.5hr\;day^{-1}$, $1hr\;day^{-1}$, $1:30hrs\;day^{-1}$ and $2hrs\;day^{-1}$ on week 1, 2, 3, and 4 respectively. Chlorophyll content and fresh and dry weight of lettuce and Chinese cabbage were measured for each treatment and analyzed through analysis of variance with a significance level of P<0.05. The result of the study showed that $CO_2$ concentration increased up to 265% and 174% and the level of temperature elevated $4.8^{\circ}C$ and $3.1^{\circ}C$ in greenhouse-1 and 2, respectively as compared to greenhouse-3 due to application of DME combustion gas. Although, the same crop management practices were provided in greenhouse-1, 2 and 3 at a same rate, the highest change (p<0.05) of chlorophyll content, fresh weight and dry weight were found from the DME-1 treatment, followed by DME-2. As a result, DME combustion gas that raised the level of temperature and $CO_2$ concentration in the greenhouse-1 and greenhouse-2, might have an effect on growth of lettuce and Chinese cabbage. At end of experiment, the highest fresh and dry weight of lettuce and Chinese cabbage were measured in greenhouse-1 and followed by greenhouse-2. Similarly chlorophyll content of greenhouse-1 and greenhouse-2 were more compared to greenhouse-3. In general, DME was not producing any harmful gas during its combustion period, therefore it can be used as an alternative to conventional fuel such as diesel and liquefied petroleum gas (LPG) for both heating and $CO_2$ supply in winter season. Moreover, endorsed quantify of DME combustion gas for a specified crop can be applied to greenhouse to improve the plant growth and enhance yield.

• MISULJARYO - National Museum of Korea Art Journal
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• v.98
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• pp.130-153
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• 2020

Using stylistic analysis and historical documents, this paper examines the production details of images enshrined in Myeongbujeon (Hall of the Underworld) at Magoksa Temple in Gongju, focusing on the wooden seated Ksitigarbha Bodhisattva and the stone Ten Kings of Hell. Inside Myeongbujeon, the wooden seated Ksitigarbha Bodhisattva is placed at the center, flanked by standing images of Mudokgwiwang and Domyeong-jonja, with images of the Ten Kings and their attendants along the walls. All of these images were transferred to Magoksa Temple in the latter half of the 1930s. The wooden seated Ksitigarbha Bodhisattva came from Jeonghyesa Temple in Cheongyang, the other sculptures came from Sinheungsa Temple in Imsil, and a painting of the Ten Kings came from Jeongtosa Temple in Nonsan. The wooden seated Ksitigarbha Bodhisattva is known to have been produced in 1677, around the same time as the stone sculptures of the Ten Kings. A close analysis of the details of the bodhisattva sculpture-including the facial features, body proportions, and drapery characteristics-strongly suggests that it was produced in the 1620s or 1630s by the monk sculptor Suyeon (who was active in the early half of the seventeenth century) or his disciples. In particular, the rendering of the drapery on the lower half of the body closely resembles Buddhist sculptures produced by Suyeon that are now enshrined at Bongseosa Temple in Seocheon (produced in 1619) and at Sungnimsa Temple in Iksan (produced at Bocheonsa Temple in Okgu in 1634). According to the votive inscription, the stone sculptures of the Ten Kings and their attendants were produced in 1677 under the supervision of the monk sculptor Seongil. However, these are the only known Buddhist images produced under Seongil, and no details about other monks involved in the production have ever been found, making it difficult to speculate about their lineage. Historical records do suggest that Seongil worked on other projects to produce or repair sculptures with disciples of the monk sculptors Hyehi or Unhye, indicating amicable relations between the two groups. Unlike most such images in the Honam or Yeongseo regions, the Ten Kings at Magoksa Temple are made from stone, rather than wood or clay. Also, the overall form and the drapery conform to statues of the Ten Kings that were popularly produced in the Yeongnam region. Thus, the images are believed to be the work of monks who were primarily active in Yeongnam, rather than Honam. In the future, a systematic investigation of wooden seated Ksitigarbha Bodhisattva images and stone Ten Kings of Hell images produced in the Chungnam region could illuminate more details about the production of the images at Magoksa Temple, and perhaps shed light on the conditions that led to the production of stone Buddhist sculptures in the Honam area during the late seventeenth century.