• Title/Summary/Keyword: 공간영역

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Application of Spectral Indices to Drone-based Multispectral Remote Sensing for Algal Bloom Monitoring in the River (하천 녹조 모니터링을 위한 드론 다중분광영상의 분광지수 적용성 평가)

  • Choe, Eunyoung;Jung, Kyung Mi;Yoon, Jong-Su;Jang, Jong Hee;Kim, Mi-Jung;Lee, Ho Joong
    • Korean Journal of Remote Sensing
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    • v.37 no.3
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    • pp.419-430
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    • 2021
  • Remote sensing techniques using drone-based multispectral image were studied for fast and two-dimensional monitoring of algal blooms in the river. Drone is anticipated to be useful for algal bloom monitoring because of easy access to the field, high spatial resolution, and lowering atmospheric light scattering. In addition, application of multispectral sensors could make image processing and analysis procedures simple, fast, and standardized. Spectral indices derived from the active spectrum of photosynthetic pigments in terrestrial plants and phytoplankton were tested for estimating chlorophyll-a concentrations (Chl-a conc.) from drone-based multispectral image. Spectral indices containing the red-edge band showed high relationships with Chl-a conc. and especially, 3-band model (3BM) and normalized difference chlorophyll index (NDCI) were performed well (R2=0.86, RMSE=7.5). NDCI uses just two spectral bands, red and red-edge, and provides normalized values, so that data processing becomes simple and rapid. The 3BM which was tuned for accurate prediction of Chl-a conc. in productive water bodies adopts originally two spectral bands in the red-edge range, 720 and 760 nm, but here, the near-infrared band replaced the longer red-edge band because the multispectral sensor in this study had only one shorter red-edge band. This index is expected to predict more accurately Chl-a conc. using the sensor specialized with the red-edge range.

A Study on the Theories of Jwajowusa(左祖右社) and Jeonmyohuchim(前廟後寢) of an Ancient Jongmyo Shrine System (고대 종묘제도의 좌조우사(左祖右社)와 전묘후침(前廟後寢) 설에 대한 일고찰)

  • Seo, Jeong-hwa
    • (The)Study of the Eastern Classic
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    • no.62
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    • pp.231-262
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    • 2016
  • The Jongmyo Shrine(宗廟) of Zhou dynasty was a king's main building where a diversity of rituals were held, such as 'the assembly ceremony between a king and vassals in the morning', and was also called as Taechim(太寢) Nochim(路寢) Jeongchim(正寢) and others. Before Zhou dynasty, the expressions of Taesil(太室) and Sesil(世室) were used, and especially the term of Taesil(太室) is found in the records of the early period of West Zhou. In "Seogyeong(書經)", not only the term of Nochim(路寢) but also the letter of 'chim(寢)' itself is not found at all, but the letter of 'sil(室)' appeared several times in the chapters of "Haseo(夏書)" "Sangseo(商書)" "Juseo(周書)" except for that of "Wuseo(虞書)". "Jwajowusa(左祖右社)" meaning that 'the Jongmyo Shrine(宗廟) which keeps the late king's mortuary tablet is established in the left, and Sajikdan altar(社稷壇) which enshrines a god of land and grains is established in the right' was first mentioned in the part of 'Janginyeongguk(匠人營國 : a master craftsman builds different national infrastructures, for instance, a palace and roads)' in "Donggwangogonggi(冬官考工記)" of "Jurye(周禮)". In addition, so-called 'Jwamyowusa(左廟右社)', that is, "Sajik(社稷) enshrining the god of land and grains is built in the right('右'), and the Jongmyo Shrine(宗廟) in the left('左'). (右社稷 左宗廟)" was mentioned as one of different duties of a Sojongbaek(小宗伯) in charge of ancestral rites, which was recorded in "Chungwanjongbaek(春官宗伯)" of "Jurye(周禮)". And it seems that had affected the mention of "Jwajowusa(左祖右社)" in "Donggwangogonggi(冬官考工記)" appeared thereafter. Many manners scholars including Jeonghyun(鄭玄) since Han dynasty interpreted 'Jwa(左 : left)' and 'Wu(右 : right)' here as the arrangement relation of left and right of Jongmyo(宗廟) and Sajik(社稷), but when it is interpreted as "helping(右=佑 : to help) to sacrifice to a god of land and grains in Sajik(社稷), and helping(左=佐 : to help) memorial ceremonies in Jongmyo(宗廟)." it can correspond with a 'Jongbaek(宗伯)''s duties. 'Jeonmyohuchim(前廟後寢)' is the term that began from the expression that "what's in front is called as an jongmyo shrine(宗廟) and what's back as a bedroom.(前曰廟 後曰寢)" in Jeonghyun(鄭玄)'s annotation explaining the chapter of "Hagwansama(夏官司馬)" in "Jurye(周禮)" and "Wolryeong(月令)" in "Yegi(禮記)". Chaeong(蔡邕), a figure in the same age as Jeonghyun(鄭玄), used the expression that "a court is placed in the front, and a bedroom in the back(前有朝 後有寢)." In the paper, two hypotheses were discussed about the theory about Jeonmyohuchim(前廟後寢). In one hypothesis, it expressed two facilities within a wall; 'a court in the front to deal with governmental affairs, and a comfortable interior space in the back.' In another hypothesis, it refers to two independent and separate buildings of 'an jongmyo shrine(宗廟) building in the front as the area of governmental meetings, and the residential building in the back as the residence area with family'.

Bioactive compounds in food for age-associated cognitive decline: A systematic review (인지기능 개선을 위한 식품유래 생리활성소재에 대한 체계적 문헌고찰)

  • Kang, Eun Young;Cui, Fengjiao;Kim, Hyun Kyung;Go, Gwang-woong
    • Korean Journal of Food Science and Technology
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    • v.53 no.3
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    • pp.278-289
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    • 2021
  • The rapid aging of society has led to a surge in cognitive dysfunction in the elderly. As there is limited evidence for the development of dementia in medicine, a shift in focus on prevention strategies using bioactive compounds in food is required. This systematic review evaluated the effects of various bioactive compounds on age-associated cognitive decline. The literature was searched for terms related to bioactive compounds in cognitive decline and article selection was limited to clinical randomized controlled trials for a single bioactive compound. We identified 21 studies that evaluated the strength of the evidence. ω-3 fatty acids and vitamin B presented a strong evidence level, whereas vitamin D and E, anserine/carnosine, and chromium were defined as having moderate levels of evidence. ω-3 fatty acids relieved cognitive decline and reduced amyloid β-related protein accumulation. Vitamin B decreased homocysteine levels, which is accompanied by alleviation of cognitive function. In conclusion, ω-3 and vitamin B have the potential to improve age-associated cognitive decline.

Analysis of Skin Color Pigments from Camera RGB Signal Using Skin Pigment Absorption Spectrum (피부색소 흡수 스펙트럼을 이용한 카메라 RGB 신호의 피부색 성분 분석)

  • Kim, Jeong Yeop
    • KIPS Transactions on Software and Data Engineering
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    • v.11 no.1
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    • pp.41-50
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    • 2022
  • In this paper, a method to directly calculate the major elements of skin color such as melanin and hemoglobin from the RGB signal of the camera is proposed. The main elements of skin color typically measure spectral reflectance using specific equipment, and reconfigure the values at some wavelengths of the measured light. The values calculated by this method include such things as melanin index and erythema index, and require special equipment such as a spectral reflectance measuring device or a multi-spectral camera. It is difficult to find a direct calculation method for such component elements from a general digital camera, and a method of indirectly calculating the concentration of melanin and hemoglobin using independent component analysis has been proposed. This method targets a region of a certain RGB image, extracts characteristic vectors of melanin and hemoglobin, and calculates the concentration in a manner similar to that of Principal Component Analysis. The disadvantage of this method is that it is difficult to directly calculate the pixel unit because a group of pixels in a certain area is used as an input, and since the extracted feature vector is implemented by an optimization method, it tends to be calculated with a different value each time it is executed. The final calculation is determined in the form of an image representing the components of melanin and hemoglobin by converting it back to the RGB coordinate system without using the feature vector itself. In order to improve the disadvantages of this method, the proposed method is to calculate the component values of melanin and hemoglobin in a feature space rather than an RGB coordinate system using a feature vector, and calculate the spectral reflectance corresponding to the skin color using a general digital camera. Methods and methods of calculating detailed components constituting skin pigments such as melanin, oxidized hemoglobin, deoxidized hemoglobin, and carotenoid using spectral reflectance. The proposed method does not require special equipment such as a spectral reflectance measuring device or a multi-spectral camera, and unlike the existing method, direct calculation of the pixel unit is possible, and the same characteristics can be obtained even in repeated execution. The standard diviation of density for melanin and hemoglobin of proposed method was 15% compared to conventional and therefore gives 6 times stable.

A study on the Construction and the Transition of Daebodan in the Late Josun Dynasty (조선후기 창덕궁 대보단의 조성과 변천에 관한 연구)

  • LEE Yeonro
    • Korean Journal of Heritage: History & Science
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    • v.55 no.4
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    • pp.96-116
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    • 2022
  • The Daebodan was an altar, which held a memorial service for emperors of the Ming dynasty. This alter, which was referred to as Hwangdan, was first constructed in 1704. When the Japanese Invasion of Korea commenced in 1592, Shinjong, the emperor of the Ming dynasty, sent reinforcements to Josun to help. This alter was made to repay Shinjong's kindness. Before this, Song-siyeol(宋時烈), Leader of Noron(老論), made a shrine at Hwayangdong to hold memorial services for Shinjong, and after some time, this developed into a national ceremony. Construction of the Daebodan largely changed the backyard of Changdukgung-palace. However considering the construction process, the meaning of the Daebodan was not a big deal. At first, the optimal place for the Daebodan was selected at the site of a inner icehouse. But the inner icehouse could not be transferred to other site due to the circumstances. After all, the Daebodan was constructed at the site of Byeoldaeyeong(別隊營) which was located in the outside of palace. Most of the stones for the new Daebodan were used ones. And the annexe of Byeoldaeyeong was used for Daebodan without any changes being made. The scale of the construction was not particularly grand. After the construction, Sukjong, who made the Daebodan, showed barely any interest in it. But the conception of the Daebodan was back again in the history by Youngjo. He was also not interested in the Daebodan during his early years of ruling time. However, in the 1740's, he started to become interested in the ceremony of Daebodan, and carried out a large-scale reconstruction of the Daebodan. Jegigo(祭器庫) was rebuilt In 1739. And Jaesil(齋室), staying one night before the ceremonial day, was added in 1745. In 1749, the Daebodan was greatly changed by enshrining Uijong and Taejo, emperors of the Ming dynasty. The shape of alter was changed. Moreover this alter was made by newly quarried stones. And several buildings, Junsachung(典祀廳), Jaesaengchung(宰牲廳) and Akgongchung(樂工廳), were added to the site. In 1762, meritorious retainers were enshrined to the Daebodan. After all the Daebodan became an important part of the backyard of Changdukgung-palace. During the reign of Jungjo, the Daebodan also was an important part of backyard of Changdukgung-palace. But significant changes were not made at that time. The only change was the moving of Kyungbonggak(敬奉閣) in 1799. Afterward the Daebodan remained unchanged. The ceremonies at the Daebodan stopped in 1908. And the Daebodan disappeared into the mist of history.

An Analysis of the Internal Marketing Impact on the Market Capitalization Fluctuation Rate based on the Online Company Reviews from Jobplanet (직원을 위한 내부마케팅이 기업의 시가 총액 변동률에 미치는 영향 분석: 잡플래닛 기업 리뷰를 중심으로)

  • Kichul Choi;Sang-Yong Tom Lee
    • Information Systems Review
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    • v.20 no.2
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    • pp.39-62
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    • 2018
  • Thanks to the growth of computing power and the recent development of data analytics, researchers have started to work on the data produced by users through the Internet or social media. This study is in line with these recent research trends and attempts to adopt data analytical techniques. We focus on the impact of "internal marketing" factors on firm performance, which is typically studied through survey methodologies. We looked into the job review platform Jobplanet (www.jobplanet.co.kr), which is a website where employees and former employees anonymously review companies and their management. With web crawling processes, we collected over 40K data points and performed morphological analysis to classify employees' reviews for internal marketing data. We then implemented econometric analysis to see the relationship between internal marketing and market capitalization. Contrary to the findings of extant survey studies, internal marketing is positively related to a firm's market capitalization only within a limited area. In most of the areas, the relationships are negative. Particularly, female-friendly environment and human resource development (HRD) are the areas exhibiting positive relations with market capitalization in the manufacturing industry. In the service industry, most of the areas, such as employ welfare and work-life balance, are negatively related with market capitalization. When firm size is small (or the history is short), female-friendly environment positively affect firm performance. On the contrary, when firm size is big (or the history is long), most of the internal marketing factors are either negative or insignificant. We explain the theoretical contributions and managerial implications with these results.

Effects of Motion Correction for Dynamic $[^{11}C]Raclopride$ Brain PET Data on the Evaluation of Endogenous Dopamine Release in Striatum (동적 $[^{11}C]Raclopride$ 뇌 PET의 움직임 보정이 선조체 내인성 도파민 유리 정량화에 미치는 영향)

  • Lee, Jae-Sung;Kim, Yu-Kyeong;Cho, Sang-Soo;Choe, Yearn-Seong;Kang, Eun-Joo;Lee, Dong-Soo;Chung, June-Key;Lee, Myung-Chul;Kim, Sang-Eun
    • The Korean Journal of Nuclear Medicine
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    • v.39 no.6
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    • pp.413-420
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    • 2005
  • Purpose: Neuroreceptor PET studies require 60-120 minutes to complete and head motion of the subject during the PET scan increases the uncertainty in measured activity. In this study, we investigated the effects of the data-driven head mutton correction on the evaluation of endogenous dopamine release (DAR) in the striatum during the motor task which might have caused significant head motion artifact. Materials and Methods: $[^{11}C]raclopride$ PET scans on 4 normal volunteers acquired with bolus plus constant infusion protocol were retrospectively analyzed. Following the 50 min resting period, the participants played a video game with a monetary reward for 40 min. Dynamic frames acquired during the equilibrium condition (pre-task: 30-50 min, task: 70-90 min, post-task: 110-120 min) were realigned to the first frame in pre-task condition. Intra-condition registrations between the frames were performed, and average image for each condition was created and registered to the pre-task image (inter-condition registration). Pre-task PET image was then co-registered to own MRI of each participant and transformation parameters were reapplied to the others. Volumes of interest (VOI) for dorsal putamen (PU) and caudate (CA), ventral striatum (VS), and cerebellum were defined on the MRI. Binding potential (BP) was measured and DAR was calculated as the percent change of BP during and after the task. SPM analyses on the BP parametric images were also performed to explore the regional difference in the effects of head motion on BP and DAR estimation. Results: Changes in position and orientation of the striatum during the PET scans were observed before the head motion correction. BP values at pre-task condition were not changed significantly after the intra-condition registration. However, the BP values during and after the task and DAR were significantly changed after the correction. SPM analysis also showed that the extent and significance of the BP differences were significantly changed by the head motion correction and such changes were prominent in periphery of the striatum. Conclusion: The results suggest that misalignment of MRI-based VOI and the striatum in PET images and incorrect DAR estimation due to the head motion during the PET activation study were significant, but could be remedied by the data-driven head motion correction.

A Thermal Time-Driven Dormancy Index as a Complementary Criterion for Grape Vine Freeze Risk Evaluation (포도 동해위험 판정기준으로서 온도시간 기반의 휴면심도 이용)

  • Kwon, Eun-Young;Jung, Jea-Eun;Chung, U-Ran;Lee, Seung-Jong;Song, Gi-Cheol;Choi, Dong-Geun;Yun, Jin-I.
    • Korean Journal of Agricultural and Forest Meteorology
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    • v.8 no.1
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    • pp.1-9
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    • 2006
  • Regardless of the recent observed warmer winters in Korea, more freeze injuries and associated economic losses are reported in fruit industry than ever before. Existing freeze-frost forecasting systems employ only daily minimum temperature for judging the potential damage on dormant flowering buds but cannot accommodate potential biological responses such as short-term acclimation of plants to severe weather episodes as well as annual variation in climate. We introduce 'dormancy depth', in addition to daily minimum temperature, as a complementary criterion for judging the potential damage of freezing temperatures on dormant flowering buds of grape vines. Dormancy depth can be estimated by a phonology model driven by daily maximum and minimum temperature and is expected to make a reasonable proxy for physiological tolerance of buds to low temperature. Dormancy depth at a selected site was estimated for a climatological normal year by this model, and we found a close similarity in time course change pattern between the estimated dormancy depth and the known cold tolerance of fruit trees. Inter-annual and spatial variation in dormancy depth were identified by this method, showing the feasibility of using dormancy depth as a proxy indicator for tolerance to low temperature during the winter season. The model was applied to 10 vineyards which were recently damaged by a cold spell, and a temperature-dormancy depth-freeze injury relationship was formulated into an exponential-saturation model which can be used for judging freeze risk under a given set of temperature and dormancy depth. Based on this model and the expected lowest temperature with a 10-year recurrence interval, a freeze risk probability map was produced for Hwaseong County, Korea. The results seemed to explain why the vineyards in the warmer part of Hwaseong County have been hit by more freeBe damage than those in the cooler part of the county. A dormancy depth-minimum temperature dual engine freeze warning system was designed for vineyards in major production counties in Korea by combining the site-specific dormancy depth and minimum temperature forecasts with the freeze risk model. In this system, daily accumulation of thermal time since last fall leads to the dormancy state (depth) for today. The regional minimum temperature forecast for tomorrow by the Korea Meteorological Administration is converted to the site specific forecast at a 30m resolution. These data are input to the freeze risk model and the percent damage probability is calculated for each grid cell and mapped for the entire county. Similar approaches may be used to develop freeze warning systems for other deciduous fruit trees.

An Implementation of Lighting Control System using Interpretation of Context Conflict based on Priority (우선순위 기반의 상황충돌 해석 조명제어시스템 구현)

  • Seo, Won-Il;Kwon, Sook-Youn;Lim, Jae-Hyun
    • Journal of Internet Computing and Services
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    • v.17 no.1
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    • pp.23-33
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    • 2016
  • The current smart lighting is shaped to offer the lighting environment suitable for current context, after identifying user's action and location through a sensor. The sensor-based context awareness technology just considers a single user, and the studies to interpret many users' various context occurrences and conflicts lack. In existing studies, a fuzzy theory and algorithm including ReBa have been used as the methodology to solve context conflict. The fuzzy theory and algorithm including ReBa just avoid an opportunity of context conflict that may occur by providing services by each area, after the spaces where users are located are classified into many areas. Therefore, they actually cannot be regarded as customized service type that can offer personal preference-based context conflict. This paper proposes a priority-based LED lighting control system interpreting multiple context conflicts, which decides services, based on the granted priority according to context type, when service conflict is faced with, due to simultaneous occurrence of various contexts to many users. This study classifies the residential environment into such five areas as living room, 'bed room, study room, kitchen and bath room, and the contexts that may occur within each area are defined as 20 contexts such as exercising, doing makeup, reading, dining and entering, targeting several users. The proposed system defines various contexts of users using an ontology-based model and gives service of user oriented lighting environment through rule based on standard and context reasoning engine. To solve the issue of various context conflicts among users in the same space and at the same time point, the context in which user concentration is required is set in the highest priority. Also, visual comfort is offered as the best alternative priority in the case of the same priority. In this manner, they are utilized as the criteria for service selection upon conflict occurrence.

Analysis of Quantization Noise in Magnetic Resonance Imaging Systems (자기공명영상 시스템의 양자화잡음 분석)

  • Ahn C.B.
    • Investigative Magnetic Resonance Imaging
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    • v.8 no.1
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    • pp.42-49
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    • 2004
  • Purpose : The quantization noise in magnetic resonance imaging (MRI) systems is analyzed. The signal-to-quantization noise ratio (SQNR) in the reconstructed image is derived from the level of quantization in the signal in spatial frequency domain. Based on the derived formula, the SQNRs in various main magnetic fields with different receiver systems are evaluated. From the evaluation, the quantization noise could be a major noise source determining overall system signal-to-noise ratio (SNR) in high field MRI system. A few methods to reduce the quantization noise are suggested. Materials and methods : In Fourier imaging methods, spin density distribution is encoded by phase and frequency encoding gradients in such a way that it becomes a distribution in the spatial frequency domain. Thus the quantization noise in the spatial frequency domain is expressed in terms of the SQNR in the reconstructed image. The validity of the derived formula is confirmed by experiments and computer simulation. Results : Using the derived formula, the SQNRs in various main magnetic fields with various receiver systems are evaluated. Since the quantization noise is proportional to the signal amplitude, yet it cannot be reduced by simple signal averaging, it could be a serious problem in high field imaging. In many receiver systems employing analog-to-digital converters (ADC) of 16 bits/sample, the quantization noise could be a major noise source limiting overall system SNR, especially in a high field imaging. Conclusion : The field strength of MRI system keeps going higher for functional imaging and spectroscopy. In high field MRI system, signal amplitude becomes larger with more susceptibility effect and wider spectral separation. Since the quantization noise is proportional to the signal amplitude, if the conversion bits of the ADCs in the receiver system are not large enough, the increase of signal amplitude may not be fully utilized for the SNR enhancement due to the increase of the quantization noise. Evaluation of the SQNR for various systems using the formula shows that the quantization noise could be a major noise source limiting overall system SNR, especially in three dimensional imaging in a high field imaging. Oversampling and off-center sampling would be an alternative solution to reduce the quantization noise without replacement of the receiver system.

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