• Title/Summary/Keyword: 구경

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A Study on Spatial Smoothing Technique for Angle of Arrival Estimation of Coherent Incoming Waves (코히어런트 입사파의 도래방향 추정을 위한 공간평균법의 개선에 관한 연구)

  • Jeong Jung-Sik
    • Journal of Navigation and Port Research
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    • v.29 no.5 s.101
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    • pp.403-408
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    • 2005
  • The techniques of estimating angle of arrival(AOA) have played a key role for enhancement of wireless communications using array antennas. Among those techniques, the superresolution algorithms, such as MUSIC and ESPRIT, calculate the covariance matrix of the array output vectors which are observed at the array antennas, and then by using eigen-decomposition of the covariance matrix, they estimate AOAs of the received signals with high accuracy. However, superresolution algorithms based eigenvalue decomposition fails to estimate AOAs under multipath environments. Under multipath environments, it is difficult to estimate AOAs of the received signals due to coherency and high-correlation. To resolve coherent signals, the covariance matrix is calculated by using the conventional spatial smoothing technique, and then the techniques based on eigen-descomposition is applied. The result of the conventional spatial smoothing technique, however, is obtained at the cost of losing effective spatial aperture. Moreover, the conventional technique ignores any information in the cross-correlations of the array outputs the subarrays. As the result, the performance for AOA estimation is degraded. In this paper, we propose a new spatial smoothing technique, which consider the cross-correlation for subarrays. By computer simulation, the AOA estimation performance of the proposed method is compared with the conventional method and evaluated.

Indexing and Retrieval Mechanism using Variation Patterns of Theme Melodies in Content-based Music Information Retrievals (내용 기반 음악 정보 검색에서 주제 선율의 변화 패턴을 이용한 색인 및 검색 기법)

  • 구경이;신창환;김유성
    • Journal of KIISE:Databases
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    • v.30 no.5
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    • pp.507-520
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    • 2003
  • In this paper, an automatic construction method of theme melody index for large music database and an associative content-based music retrieval mechanism in which the constructed theme melody index is mainly used to improve the users' response time are proposed. First, the system automatically extracted the theme melody from a music file by the graphical clustering algorithm based on the similarities between motifs of the music. To place an extracted theme melody into the metric space of M-tree, we chose the average length variation and the average pitch variation of the theme melody as the major features. Moreover, we added the pitch signature and length signature which summarize the pitch variation pattern and the length variation pattern of a theme melody, respectively, to increase the precision of retrieval results. We also proposed the associative content-based music retrieval mechanism in which the k-nearest neighborhood searching and the range searching algorithms of M-tree are used to select the similar melodies to user's query melody from the theme melody index. To improve the users' satisfaction, the proposed retrieval mechanism includes ranking and user's relevance feedback functions. Also, we implemented the proposed mechanisms as the essential components of content-based music retrieval systems to verify the usefulness.

The Development of X-ray Unit of Remote Emergency medical System (원격응급시스템에 적합한 X-ray 장치 개발)

  • Cho, Dong-Heon;Koo, Kyung-Wan;Yang, Hae-Sool;Han, Man-Seok;Han, Sang-Ok
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.20 no.6
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    • pp.49-54
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    • 2006
  • The X-ray unit developed by this study is to diagnose emergency cases which is too far from a hospital and to classify the patients. We have to use the X-ray in a ambulance or the scene of an accident where we cannot use the AC220 outlet because of the distance from a hospital as well. The X-ray unit developed has a characteristics as follows. First of all, as the unit has a condenser in itself where there is no electric supply, we can use the X-ray inspector in a mountain area or a island. Second, we can detect by digital detector the information taken by X-ray from DC 12[V] electricity and store as a form of file. A control circuit can secure the reliability of the X-ray unit by using the Pic16F84A X-ray and provide various functions. The X-ray unit which suits remote emergency system can be efficiently used for the emergent cases who is too far from a doctor and a hospital or in the situation where it is difficult to diagnose, transcribe and treat simultaneously.

Visual Specificity of the Pyongyang Landscape - Perspectives of North Korea Tourism - (서구권의 북한 관광을 통해 본 평양 경관의 시각적 특수성)

  • Ahn, Jin-hee;Pae, Jeong-Hann
    • Journal of the Korean Institute of Landscape Architecture
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    • v.44 no.4
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    • pp.66-74
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    • 2016
  • In what way is the urban landscape of North Korea used today, and what features do people prefer in the North Korean landscape? This study analyzed the characteristics of Pyongyang landscapes and their effects, based on an analysis of Western tourists motivation for tourism in North Korea and preferred enjoyment-seeking experiences. Using data from the tourist agency specializing in Western tourism in North Korea and a location based photo-sharing service, the study interprets the visual distinctiveness of Pyongyang landscape. The study concluded that widely known risk to travelers in North Korea is in fact an attraction, making people want to visit directly. However, this risk was mitigated in practical experience by the overall intermediation of the tourism agency and locals' conscious behavior to keep their distance from foreigners. Next, the scope of National ritual attributes was expanded to the locals' daily life as well as large-scale events such as mass games and military parades only if for national holidays. Also, the most preferred factors contributing to North Korean tourism were based on departure from routine through mobilization of the residents. This indicates the extension that the nature of North Korea as a theater state. The Pyongyang landscape represents a world politically isolated, people's congregated motion to display to the world, and people's lives hidden beneath a veil. These visualities fulfill the fantasy of Westerners regarding North Korea. Furthermore, these are superficial images that help create a basis to maintain the North Korea regime.

A Study on the Characteristics and Landscape Meaning Analysis of 'Gumi and Sipalgyung' in Jeongseon Gumijeongsa (정선 구미정사의 성격과 '구미(九美) 18경'의 경관의미)

  • Kim, Soonki;Rho, Jae-Hyun
    • Journal of the Korean Institute of Traditional Landscape Architecture
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    • v.34 no.2
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    • pp.63-74
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    • 2016
  • The purpose of this study is to expand a prospect of a few-remaining Byeolseo scenic sites of Gangwon-do(Province) through determining placeness formation, prospect characteristics, and landscape meanings of Gumi(Nine beauties) and Sipalgyung(18 scenic views) in Gumijeongsa. Gumijeongsa, which is located in a riverside of the Goljicheon(stream), a part of upstream of Namhangang, is the oldest existing Nujung architecture in the Jeongseon area. This study tried to unearth the Gumijonegsa's locational and formational characteristics through literature review and a field survey. Especially, through the field survey, this study tried to figure out the landscape meanings and contents of Gumi and Sipalgyung by Gumijeongsa's position and its prospect compositions. As a result of this study, Gumi and Sipalgyung of Gumijeongsa are variations of typical traditional culture of Gugok(Nine river bends) and Palgyung(Eight scenic views). Ja Lee, the founder, administrated Gumijeongsa as a core residence of Gugok culture. He established beautiful nine viewpoints from the building, named Gumi, and added 18 detailed landscapes(two landscapes for one beauties), instead of establishing nine river bends of the stream. The Gumi and Sipalgyung are formed by reflection of beautiful locational characteristics from the views in Gumijeongsa, thus the Gumi is the concept which is a unique variation of Gugok and Palgyung culture.

A Study on Landscape Characteristics of Flower-viewing Sites through Historical Literatures in the Late Joseon Dynasty (문헌을 통해 본 조선후기 꽃놀이 명소의 경관 특성)

  • Lee, Jaei;Sung, Jong-Sang
    • Journal of the Korean Institute of Traditional Landscape Architecture
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    • v.34 no.2
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    • pp.35-44
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    • 2016
  • This study targets flower-viewing sites appearing in "Kyungdojapji" and talks about the seasonal customs and tourist attractions of the later Chosun; Pilundae, Bukdun, Outside of Dongdaemun, Cheonyunjeong and near Seodaemun etc. Through related poetry, paintings and maps, it looks into what scenic elements each attraction was made of and how the elements were felt by visitors. It sub-divided and analyzed scenic features into objective objects, subjective emotions and experienced behaviors. As a result, representative objective objects were flowers and there were also scenes where people enjoyed poem-writing meetings along with drinking-related physical elements such as liquor, liquor glasses, liquor bottles etc. Through drawing out scenes, where users gave meaning to objective objects, it tried to interpret what space meant to them, through which the meaning of flower-viewing attractions is first and foremost a space to enjoy artistic taste. Each space is used as the center of cultural creation such as literary people gathering, viewing flowers, drinking and having poetry-writing meetings. Second, as shown in scenes viewers depicted in each space, visitors were confirmed to enjoy scenes through multi-sensory appreciation. By this, flower-viewing attractions were confirmed to be not just flower-viewing but also venues of sensory experience. This study, which drew out the scenic features of traditional flower-viewing attractions, is expected to be basic material in tracing the flower-viewing enjoyed by our ancestors as a pastime and its spatial meaning and in planning Korea-unique flower-viewing attractions.

An Experimental Study on the Effect of Subperiosteal Transplantation of Fracture Site Hematoma: Focus on the Scintigraphic Detection (골절부위에 생긴 혈종의 골막하 이식이 골형성에 미치는 영향에 관한 실험적 연구 - 골스캔 소견을 중심으로 -)

  • Yang, Seoung-Oh;Kang, Hung-Sik;Chang, Kee-Hyun;Lee, Myung-Chul;Koo, Kyung-Hoi;Seung, Sang-Chul;Park, In-Ae
    • The Korean Journal of Nuclear Medicine
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    • v.24 no.1
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    • pp.124-132
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    • 1990
  • It has been reported that hematoma is one of the most crucial factors in fracture healing since callus formation is disturbed by washing out the hematoma near a fracture site. However, it is not clear why the hamatoma is important and how it plays a role during the fracture healing. In order to investigate the role of hematoma in the process of fracture healing, the osteogenic potential by subperiosteal transplantation have been studied. Experimental fractures by operation were made at the mid-shaft of the tibia in New Zealand white rabbits. Removal of hematoma at the fracture site was done after 2 and 3 days from experimental fracture, and the removed hematoma was transplanted into the subperiosteal area at the mid-shaft of the ulna of each rabbit. As control groups, we have performed 3 different procedures 1) the hematoma was transplanted into the muscular layers at the thigh and forearm; 2) autologous blood clots were transplanted into the subperiosteal area of the ulna; and 3) sham operation without a transplantation into the subperiosteal area. After transplantation, serial bone scintigraphy and simple radiography were performed at 4 days, 1 week, and 2 weeks to detect an abnormality. The results of bone scintigraphy were positive in 5 of 6 experimental group. However, all in three control groups were negative. Histological observation of the positive bone revealed new bone formation with trabeculation. These results suggest the hematoma in fracture site has osteogenic potential in the subperiosteal area which can be demonstrable by bone scintigraphy and histologic findings. Therefore, it is considered that hematoma of the fracture site plays an important role in the process of fracture healing. Further biochemical investigation using various experimental models is mandatory to apply this preliminary result to the treatment of clinical delayed union or nonunion.

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Role of Dacryoscintigraphy in the Diagnosis and Treatment of Pediatric Patients with Epiphora (유루를 호소하는 소아 환자의 진단 및 치료에서 누비공신티그라피의 역할)

  • Jeong, Hwan-Jeong;Bom, Hee-Seung;Song, Ho-Cheon;Min, Jung-Jun;Kim, Ji-Yeul;Jeong, Sang-Ki;Park, Yeoung-Geol
    • The Korean Journal of Nuclear Medicine
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    • v.33 no.4
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    • pp.362-367
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    • 1999
  • Purpose: We conducted this study to evaluate the role of dacryoscintigraphy in the diagnosis and treatment of pediatric patients with epiphora. Materials and Methods: In 58 patients aged from 2 months to 15 years (mean age $2.8{\pm}2.3$ years), dacryoscintigraphy was performed using a gamma camera with 4 mm pinhole collimator. We correlated symptoms with dacryosicntigraphic findings in all patients. In 37 patients who underwent ophthalmologic procedures, we analyzed the agreements of dacryoscintigraphic findings with the operation. Results: High rates of agreements between epiphora and obstruction on dacryoscintigraphy (69/72, 95.8%), and between scintigraphic obstructive findings and operation sites (44/47, 93.6%) were noted. Nine of foully-four (20.5%) asymptomatic eyes showed obstructive findings on dacroscintigraphy. Conclusion: In pediatric patients with epiphora, dacryoscintigraphy is a useful tool not only in diagnosing nasolacrimal duct obstruction but also in making a decision for therapeutic procedures.

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Characteristics of Quality and Volatile Flavor Compounds in Raw and Frozen Pine-mushroom (Tricholoma matsutake) (생송이 버섯과 냉동송이 버섯의 품질 및 향기 성분 특성)

  • Ku, Kyung-Hyung;Cho, Myung-Hee;Park, Wan-Soo
    • Korean Journal of Food Science and Technology
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    • v.34 no.4
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    • pp.625-630
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    • 2002
  • Raw pine-mushrooms (Tricholoma matsutake Sing.) of four grades and those frozen were analyzed for proximate composition, smell pattern, volatile flavor compounds, and sensory evaluation. Proximate compositions of raw pine-mushrooms (A-C, regular grade) were $89.48{\sim}90.77%$ moisture, 6.81% ash excluding D (below regular grade) sample, $2.24{\sim}2.52%$ crude lipid, and $16.19{\sim}20.01%$ crude protein. Proximate compositions of frozen pine-mushrooms preserved for 6 months at -20 and $-70^{\circ}C$ showed no difference compared with raw pine-mushrooms. Results of smell pattern and multidimensional analysis revealed raw pine-mushrooms showed no differences among samples, but frozen pine-mushrooms differed significantly depending on the grade. Volatile flavor compounds of pine-mushrooms were analyzed using a purge and trap method with GC/MSD. Twenty-nine volatile compounds were identified, among which alcohols such as 1-octen-3-ol, 2-octen-1-ol, 3-methyl-butanol, and n-octanol were commonly found in all pine-mushroom samples. In sensory attributes, raw pine-mushrooms were not significantly different at 5% level, and sample D of frozen pine-mushrooms scored lower than samples $A{\sim}C$.

Evaluating Performance of Cable-Inspection Robot in Cable-Supported Bridge (케이블지지 교량의 케이블 점검 로봇 성능 평가)

  • Kim, Jaehwan;Seo, Dong-Woo;Jung, Kyu-San;Park, Ki-Tae
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.24 no.1
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    • pp.74-79
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    • 2020
  • Safety inspection of cable-supported bridge has increasingly attention as many cable-supported bridges are currently constructed/operated. Whilst cables as a main component in cable-supported bridge should be inspected regularly, traditional method (visual inspection) has limitation to check the condition of cables properly due to restricted factors. It is evidently necessary to develop cable-inspection robot to overcome this concern. In this respect, the main aim in this study is to manufacture the improved robot compared with the existing robot. The improved functions of the robot in this study were that the robot can be operated in large cable diameter (greater than 200 mm) and climbing ability of the robot increases. In addition, electro-magnetic sensor as a non-destructive method in the robot was added to detect damaged cables and performance of the sensor was evaluated in indoor and field experiments. Consequently, the robot was able to move on the cable with ~0.2m/s and to detect damaged cables using the sensor. It was also confirmed that performance of the robot in field test is similar to that in indoor test.