52 research outputs found
κ³ μ±λ₯ λλ Ένμ μ κ³ λ°©μΆ μμ
νμλ
Όλ¬Έ (λ°μ¬)-- μμΈλνκ΅ λνμ : 곡과λν κΈ°κ³ν곡곡νλΆ, 2018. 2. κΉμ©ν.By taking advantage of the superior material properties and high aspect ratio geometry of nanocarbon materials, many researchers have been able to devote their efforts toward the development of nanocarbon emitters, which are capable of providing low turn-on voltage, high emission current density and long-term emission stability. Electron beams of field emitter are widely employed in various applications, including X-ray photography and computed tomography (CT) scans in hospitals, fault detection of semiconductor devices, airport security, and terahertz generation. Moreover, electron beam generators are progressively becoming more miniaturized, light-weighted, and low-powered so that they can be applied to diverse areas.
For a high performance field emitter, new concept of field emitter is needed to overcome the previous research. In this thesis, four novel approaches are developed in terms of fabricating the multidimensional field emitters.
1) CNT point emitter with graphene interfacial layer: we report graphene as an interfacial layer between the metal and CNTs to improve the interfacial contact. The interfacial graphene layer results in a dramatic decrease of the electrical contact resistance by an order of 2 and an increase of the interfacial thermal conductivity by 16%. Such a high improvement in the electrical and thermal interface leads to superior field emission performance with a very low turn-on field of 1.49 V ΞΌmβ1 at 10 ΞΌA cmβ2 and a threshold field of 2.00 V ΞΌmβ1 at 10 mA cmβ2, as well as the maximum current of 16 mA (current density of 2300 A cmβ2).
2) CNT line emitter using clamping process: we report a robust and scalable method to fabricate high-performance carbon nanotube (CNT) line emitters by using a macroscopic mechanical clamping process. The process utilizes a handheld, metallic tongs (which also serves as an electrode for field emission) to pick up vertically aligned, super-grown CNTs from a substrate. By applying mechanical compression to a CNT forest in the uniaxial direction, the hemicylindrical shape of CNT structure strongly held with the tongs electrode is fabricated. With robust mechanical, thermal, and electrical contact characteristics created by mechanical clamping of CNTs, the CNT line emitter shows superior field emission performance with an emission current of 43 mA, a current density of 2700 mAcm-2, and stable operation over 10 hours. Furthermore, an extremely high emission current of 103 mA is achieved by clamping multiple CNT forests in a single tongs, showing prompt applicability of the present emitter for high-power electron beam sources.
3) Holey graphene film as a planar field emitter: we introduce an emitter in the shape of a hole, or hole emitter. An array of holes in graphene film can serve as a planar emitter, in which each circular hole is an emitter. Because of the nature of the sidewall emission through the edge of graphene film, the present planar emitter does not need any cumbersome process of leveling off emitter height and contriving to obtain the desirable inter-distance between emitters. Therefore, the screening effect and the field emission uniformity considered as obstacles in developing high efficiency planar emitters are easily resolved by an optimal design of the circular hole array. Moreover, the graphene film emitter is so flexible that it can be wrapped around a cylindrically shaped anode. This flexibility allows the present emitter to be used as a high power electron beam source because of the focusing of the emitted electron beams rendered by the concavely curved surface.
4) Carbonized cork emitter for multi-dimensional field emission: to broaden the range of application of electron beams, low power field emitters are needed that are miniature and light. We introduce here carbonized cork as a material for field emitters. The light natural cork becomes graphitic honeycomb upon carbonization, with the honeycomb cell walls 100-200 nm thick and the aspect ratio larger than 100, providing an ideal structure for the field electron emission. Compared to nanocarbon field emitters, the cork emitter produces a high current density and long-term stability with a low turn-on field. The nature of cork material makes it quite simple to fabricate the emitter. Furthermore, any desired shape of emitter tailored for the final application can easily be prepared for point, line, or planar emission.Chapter 1 Introduction 1
Chapter 2 CNT point emitter with graphene interfacial layer 5
2.1 Background of CNT point emitter 6
2.2 Experimental section 8
2.3 Result and discussion 10
2.4 Conclusion 27
Chapter 3 CNT line emitter using clamping process 28
3.1 Background of CNT line emitter 29
3.2 Experimental section 31
3.3 Result and discussion 32
3.4 Conclusion 46
Chapter 4 Holey graphene film as a planar field emitter 47
4.1 Background of planar emitter 48
4.2 Result and discussion 50
4.3 Conclusion 64
Chapter 5 Carbonized cork emitter for multidimensional field emission 65
5.1 Background of low turn-on field emitter 66
5.2 Experimental section 68
5.3 Result and discussion 72
5.4 Conclusion 93
Chapter 6 Conclusions 94
Bibliography 97
Abstract 122Docto
A Study on Navigable Spatial Planning using Big Data on Maritime Traffic in Geographic Information System Environment
μ΅κ·Ό ν΄μ곡κ°μ μ¬μ©νλ 주체λ€μ μν΄ κ΅¬μ²΄μ κ΄λ¦¬μ²΄κ³ μμ΄ μ μ μμΌλ‘ μ΄μ©λκ³ μλ€. ν΄μ곡κ°μ μ΄μ©νλ μ£Όμ²΄λ€ κ°μ κ°λ±μ΄ μ¬νλλ©΄μ ν΄μ λκ°λ°μ΄ λ°μνλ©° μ¬νμ μΈ λ¬Έμ κ° λκ³ μλ€. μ΄λ¬ν λ¬Έμ λ₯Ό ν΄κ²°νκΈ° μν΄ μκ΅, 벨기μ, λ―Έκ΅, λ€λλλ λ±μ ν΄μ곡κ°μ μ©λλ₯Ό 체κ³μ , μ λμ μΌλ‘ λΆλ¦¬νμ¬ μ΄μ© 주체λ€μκ² μ 곡νκ³ μλ€. νΉν, ν΄μκ³΅κ° μ΄μ© 주체 μ€ ννꡬμμ λ€λ₯Έ λͺ©μ μ ν΄μ μ©λλ³΄λ€ μ΅μ°μ μ λκ³ , ννμ ν보ν μ μκ² νλ€.
μ°λ¦¬λλΌλ λΆμ° μΈκ·Ό ν΄μμ ν΄μ곡κ°κ΄λ¦¬κ³νμ μ립 λ° λ°ννμλ€. ν΄μμ©λꡬμμΌλ‘ μ΄μ
νλ보νΈκ΅¬μ, 골μ¬Β·κ΄λ¬Όμμκ°λ°κ΅¬μ, ν΄μκ΄κ΄κ΅¬μ, νκ²½Β·μνκ³κ΄λ¦¬κ΅¬μ, μ°κ΅¬Β·κ΅μ‘보μ ꡬμ, νλ§Β·ννꡬμ, κ΅°μ¬νλꡬμ, μμ κ΄λ¦¬κ΅¬μμΌλ‘ λΆλ¦¬νμλ€. μ¬κΈ°μ νλ§Β·ννꡬμμ΄ ν¬ν¨νλ μμμ μν΄μ κ²½μ° 17.36%μ΄λ©°, λ°°νμ κ²½μ μμμμλ 1.07%λ‘ λνλλ€. μν΄ μμμ νκ³ λ΄λΆ, κ΅ν΅μμ νΉμ ν΄μμΌλ‘λ§ μ μ λμ΄ μμΌλ©°, μ λ°μ΄ νννκΈ° μν μ΄μΈμ ν΄μμμλ ννꡬμμΌλ‘ μ μ λμ΄ μμ§ μλ€.
λ³Έ μ°κ΅¬λ ν΄μ곡κ°κ³ν(Marine Spatial Planning, MSP)μμ μ λμ μΈ λ°©λ²μΌλ‘ νν곡κ°κ³νμ μ립 λ°©λ²μ μ μνκ³ μ νλ€. μ€μΈ‘ ν΄μκ΅ν΅ λ°μ΄ν° κΈ°λ°μΌλ‘ μ λ°μ νν λ°μ§λλ₯Ό μ°μΆν ν, μλ‘μ΄ λ°©λ²μ νλ‘ μμ± μκ³ λ¦¬μ¦μ μ μ©νμ¬ νλ‘μ μμ μ±μ κ²μ¦νλ€. μμ±λ νλ‘μ μμ μ± κ²μ¦ μ΄ν, ννꡬμμ μ μ©μ΄ κ°λ₯νμ§ νμ
νκ³ νλ‘λ₯Ό μ μ€ν ν΄μ λλ νλ‘μ μμ μ΄ μꡬλλ ν΄μμ μ μ©νκ³ μ νλ€.
νλ‘ μμ± μκ³ λ¦¬μ¦μ μ μ©νκΈ° μν΄ 1λ
κ°μ μ λ°μλμλ³μμ€ν
(Automatic Identification System, AIS) ν΄μκ΅ν΅ λΉ
λ°μ΄ν° κΈ°λ°μΌλ‘ KDE(Kernel Density Estimation)λΆμμ μννμλ€. μ¬μ©λ Kernel ν¨μλ Quarticμ μ¬μ©νμκ³ , μ 체 ν΄μ κ΅ν΅λμμ 90%λ₯Ό ννꡬμμΌλ‘ μ μ ν ν΄μΈ μ¬λ‘λ₯Ό μ μ©νμ¬ λΆμνμλ€. 90%μ KDE λΆμ κ²°κ³Όλ₯Ό κΈ°λ°μΌλ‘ μ΄λ―Έμ§ μ²λ¦¬ μκ³ λ¦¬μ¦μ μννμ¬ νλ‘ λΆλΆκ³Ό κ·Έλ μ§ μμ λΆλΆμΌλ‘ λλκΈ° μν΄ Otsu μ΄μ§ν μκ³ λ¦¬μ¦μ μννμλ€. μ΄μ§ν κ³Όμ μν ν, νλ‘μ κ°μ₯μ리λ₯Ό μΆμΆνκΈ° μν΄ Sobel, Laplacian, Cannyμ μκ³ λ¦¬μ¦μ μ μ©νμμΌλ©°, μ΄ μ€ κ°μ₯ μ ννκ² μΆμΆλλ Canny μκ³ λ¦¬μ¦μ λΆμμ μ¬μ©νμλ€. νλ‘μ κ°μ₯μ리λ μ μΌλ‘ μ΄λ£¨μ΄μ Έ μμΌλ©° μ κ³Ό μ μ΄ λ§λλ μ§μ μΈ μ½λλ₯Ό μΆμΆνκΈ° μν΄ Harris νμ§ μκ³ λ¦¬μ¦μ μ¬μ©νμλ€.
μ΄μ κ°μ΄ μ΄λ―Έμ§ μ²λ¦¬ μκ³ λ¦¬μ¦μ μννλ€λ©΄ μμ±λ νλ‘μ μ΄κΈ° λͺ¨μ΅μ λνλΌ μ μλ€. νμ§λ§, μμ±λ νλ‘μ μ΄κΈ°λͺ¨μ΅μ μΌλΆ ꡬκ°μ΄ μΈνλΆννλ©° λμ΄μ Έ μλ λΆλΆμ΄ μ‘΄μ¬νλ€. μ΄λ₯Ό λΌμΈ μ€λ¬΄μ± μμ
μ ν΅ν΄ νλ‘λ₯Ό λΆλλ½κ² λ§λ€μ΄μ£Όκ³ λμ΄μ Έ μλ λΆλΆμ μ°κ²°νλ€. λΆλλ½κ² μμ±λ νλ‘ κ΅¬μμ λ€λ‘λ€ μΌκ°λΆν μ μ μ©νμ¬ μΌκ°νμΌλ‘ λΆν νλ€. μμ±λ μΌκ°νμ μ΄μν μΌκ°νμ κ°μμ λ°λΌ μμ±κ°μ 1 ~ 3κΉμ§ μ
λ ₯ νκ³ , κ°λ³ μμ±κ°μ λ
Έλ, 컀λΈ, μΈκ·Έλ¨ΌνΈλ₯Ό ꡬμ±ν μ μλ€. μΈκ·Έλ¨ΌνΈλ₯Ό λͺ¨λ μ°κ²°νλ©΄ μ΅μ’
μ μΌλ‘ νλ‘μ μΌν°λΌμΈμ μμ±ν μ μλ€.
μμ±λ μΌν°λΌμΈμ νλ‘ μμ μ± μΈ‘λ©΄μμ λΉκ΅νκΈ° μν΄ κΈ°μ‘΄ νλ‘μ μΌν°λΌμΈκ³Ό ꡴곑λ κ²μ¦, κ΅κ° κ²μ¦, RCE(Route Change Envelope) κ²μ¦μ μννλ€. μΌλΆ ꡬκ°μ μ μΈνκ³ , μμ±λ μΌν°λΌμΈμ μμ μ± μΈ‘λ©΄μμ μ°μν κ²°κ³Όλ₯Ό κ°μ ΈμμΌλ©°, μ΄λ₯Ό ν΄μ곡κ°κ³νμ ννꡬμμΌλ‘ μ μ νλ€.So far, various user using marine space around the world have been using it preemptively without a comprehensive management. Such practice has caused such social problems as increased conflicts between marine users and has led to excessive development of marine space. In an effort to resolve such issues, European countries, China, Japan, and the United States categorized marine space systematically and quantitatively prior to providing the area to the users. Especially, the navigation areas among the user using marine space are given priority over other purposes of marine use, and enables navigation routes to be secured.
In the Republic of Korea, the Ministry of Oceans and Fisheries and Busan Metropolitan City established and announced the Marine Spatial Management Planning for exclusive economic zones and territorial sea for the first time since the implementation of the Marine Spatial Planning Act. The planning divided marine-use areas into the following zones: fishery activity protection zone; aggregate, mineral resource development zone; marine tourism zone; environment, ecosystem management zone; research and education conservation zone; port, shipping zone; military activity zone; and safety management zone. Here, the area covered by the port, shipping zone represents 17.36% of the territorial sea, and the figure stands at 1.07% in the exclusive economic zone. The designated territorial sea refers to the selected areas only inside the busan harbour limit and the traffic safety designated areas. The sea is not designated as a navigable area if it does not serve the purpose of the space required for sailing.
With the aid of a quantitative method, this study attempts to create novel maritime routes β while employing the big data of the maritime traffic to establish navigable areas - in the Marine Spatial Planning (MSP). To perform such task, the traffic density would be calculated based on the actual traffic data, while the safety of the novel maritime route would be verified by applying the new method of the route generating algorithms. Following the verification of the safety of the novel maritime route, this research will subsequently determine whether it can be applied to the navigable areas of the marine spatial planning, and then use it to the areas where the route is to be established or the areas requiring modification of the routes.
To apply the route generating algorithms, a one-year KDE (Kernel Density Estimation) analysis, based on the AIS (Automatic Identification System) marine traffic big data, was performed. The Quartic was used for Kernel function, and it was analyzed by applying overseas cases, in which 90% of the total sea traffic was selected as a navigation zone. The image processing algorithm based on the result of 90% KDE analysis was conducted. Also, in order to separate the areas into the route part and the non-route part, the Otus binarization algorithm was used.
After performing the image binarization process, Sobel, Laplacian, and Canny's algorithms were applied to extract the boundary of the routes. As a result, Canny algorithm - the most accurate on obtaining boundaries - was used for the analysis. The boundary of the route consists of lines, and the Harris detection algorithm was used to extract the corners where the lines meet one another. When the image processing algorithms are executed as above, it is possible to present the initial appearance of the generated route. However, the routes created by applying the image processing algorithms display some sections as uneven or cut off. The line smoothing operation could smoothen out the lines and combine cut-off parts. Then, the smoothened out route areas could be divided into triangles by applying the Delaunay triangulation. Depending on the number of triangles adjacent to the generated triangles, we can enter the attribute values from 1 to 3, and the individual attribute value can be composed of nodes, curves, and segments. When all segments are connected, it becomes finally possible to create the centerline of the route.
The generated centerline is compared with the centerline of the original route in terms of stability. To carry out the comparisons, the sinuosity verification, the intersection angle verification, and the route change envelope(RCE) are performed.
In the end, the centerline of the newly generated route, with few exceptions, achieved excellent results in terms of stability, and we intend to select it as a navigable area of the Marine Spatial Planning.λͺ© μ°¨
Abstract vii
κ΅λ¬Έμ΄λ‘ x
μ 1 μ₯ μ λ‘ 1
1.1 μ°κ΅¬ λ°°κ²½ λ° λͺ©μ 1
1.2 μ°κ΅¬ λ°©λ² 4
μ 2 μ₯ κ΅λ΄μΈ νν곡κ°κ³ν λν₯ 6
2.1 ν΄μ곡κ°κ³ν(Marine Spatial Planning, MSP) μ μ 6
2.2 νν곡κ°κ³ν ν΄μΈλν₯ 7
2.2.1 μκ΅ 8
2.2.2 벨기μ 12
2.2.3 λ―Έκ΅ 15
2.2.4 λ€λλλ 20
2.3 νν곡κ°κ³ν κ΅λ΄λν₯ 21
2.3.1 ν΄μ곡κ°κ³ν μ립 νν© 21
2.3.2 νλ§ λ° ννꡬμ νκ³μ 23
μ 3 μ₯ μμ§ λ°μ΄ν° μ μ²λ¦¬ λ° λΆμ νλ‘κ·Έλ¨ 27
3.1 μ λ°μλμλ³μμ€ν
κ°μ 27
3.2 AIS λ°μ΄ν° νΉμ§ λ° μ μ²λ¦¬ κ³Όμ 30
3.3 λΆμ νλ‘κ·Έλ¨ 35
3.3.1 μ§λ¦¬κ³΅κ°μ 보μμ€ν
35
3.3.2 곡κ°μ 보 λΆλ₯ 35
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4.1 νλ‘ μμ± μκ³ λ¦¬μ¦ 43
4.1.1 νλ‘ μμ± ν΄μ λͺ¨λΈλ§ 43
4.1.2 νλ‘ μμ± μκ³ λ¦¬μ¦ κ°μ 44
4.2 KDE(Kernel Density Estimation) λΆμ 46
4.2.1 KDE κ°μ 46
4.2.2 GIS κΈ°λ° KDE λΆμ 47
4.2.3 KDE λΆμ κ²°κ³Ό 49
4.3 νλ‘ μμ± μ΄λ―Έμ§ μ²λ¦¬ κΈ°λ² 53
4.3.1 μ΄λ―Έμ§ μ΄μ§ν μκ³ λ¦¬μ¦ 53
4.3.2 κ°μ₯μ리 μΆμΆ μκ³ λ¦¬μ¦ 58
4.3.3 μ½λ νμ§ μκ³ λ¦¬μ¦ 64
4.4 νλ‘ μΌν°λΌμΈ μΆμΆ λͺ¨λΈλ§ 69
4.4.1 λΌμΈ μ€λ¬΄μ± μκ³ λ¦¬μ¦ 69
4.4.2 λ€λ‘λ€ μΌκ°λΆν μκ³ λ¦¬μ¦ 74
μ 5 μ₯ μμ± νλ‘μ λΉκ΅ λ° κ²μ¦ 80
5.1 νλ‘ μμ μ± κ²μ¦ 80
5.1.1 ꡴곑λ κ²μ¦ 80
5.1.2 κ΅κ° κ²μ¦ 84
5.1.3 RCE κ²μ¦ 87
5.2 μμ± νλ‘ νν곡κ°κ³ν μ μ© 92
μ 6 μ₯ κ²° λ‘ 94
6.1 μ°κ΅¬μ κ²°λ‘ 94
6.2 ν₯ν μ°κ΅¬ κ³Όμ 96
μ°Έκ³ λ¬Έν 98Maste
Relationship between abstract thinking and eye gaze pattern in patients with schizophrenia
BACKGROUND:
Effective integration of visual information is necessary to utilize abstract thinking, but patients with schizophrenia have slow eye movement and usually explore limited visual information. This study examines the relationship between abstract thinking ability and the pattern of eye gaze in patients with schizophrenia using a novel theme identification task.
METHODS:
Twenty patients with schizophrenia and 22 healthy controls completed the theme identification task, in which subjects selected which word, out of a set of provided words, best described the theme of a picture. Eye gaze while performing the task was recorded by the eye tracker.
RESULTS:
Patients exhibited a significantly lower correct rate for theme identification and lesser fixation and saccade counts than controls. The correct rate was significantly correlated with the fixation count in patients, but not in controls.
CONCLUSIONS:
Patients with schizophrenia showed impaired abstract thinking and decreased quality of gaze, which were positively associated with each other. Theme identification and eye gaze appear to be useful as tools for the objective measurement of abstract thinking in patients with schizophrenia.ope
A hybrid technique for sinus floor elevation in the severely resorbed posterior maxilla
PURPOSE: This study aimed to evaluate the effectiveness of the modified sinus floor elevation technique described hereafter as a "hybrid technique," in 11 patients with severely resorbed posterior maxillae. METHODS: Eleven patients who received 22 implants in the maxillary premolar and molar areas by the hybrid technique were enrolled in this study. A slot-shaped osteotomy for access was prepared on the lateral wall along the lower border of the sinus floor. The Schneiderian membrane was fully reflected through the lateral slot. Following drilling with the membrane protected by a periosteal elevator, the bone was grafted. All implants were placed simultaneously with sinus augmentation. The cumulative success rate was calculated and clinical parameters were recorded. Radiographic measurements were performed. RESULTS: All implants were well maintained at last follow up (cumulative success rate=100%). The mean residual bone height, augmented bone height, crown-to-implant ratio, and marginal bone loss were 4.1+/-1.64 mm, 8.76+/-1.77 mm, 1.21+/-0.33 mm, and 0.34+/-0.72 mm, respectively. CONCLUSIONS: Simultaneous implant placement with sinus augmentation by hybrid technique showed successful clinical results over a 2-year observation period and may be a reliable modality for reconstruction of a severely resorbed posterior maxillaope
μλ°μ κ·Όμ λ κ΅°λ§λμ κ±°λμ λν μ€νμ μ°κ΅¬
νμλ
Όλ¬Έ(μμ¬)--μμΈλνκ΅ λνμ :ν λͺ©κ³΅νκ³Ό,1998.Maste
(A) study of oral flora and inorganic constituents of dental plaque of Korean women
μνκ³Ό/λ°μ¬[νκΈ]
[μλ¬Έ]
Dental plaque is generally considered to be of paramount significance in the etiology of dental caries and periodontal disease. Its microbial content, biochemical composition and its mode of formation may be great important to control of dental disease.
Since Miller(1890) had proposed that bacteria which producing sufficient acid to decalcify the tooth were etiologic agents of dental caries, almost all investigators aimed at the control of caries was directed towards increasing the resistance of the tooth to acid dissolution. Stephan(1953) has reviewed the historical development of the plaque concept. In the intervening years, a number of investigators attempted to equate the specific microorganisms with plaque formation and dental caries because of their ability to produce mucinous polysaccharides from sucrose.
A nummerous researchers have been participated to seek for the nature and role of dental plaques by bacteriological, biochemical and pathological methods or electron microscopic examination and fluorescent antibody techniques. Its microbial content, mode of formation and relationship to dental caries and periodontal disease, have been discussed in several recent reviews(Mandel, 1966; Leach, 1970; Dawes, 1968; Jenkins 1968, 1972; Keyes, 1968; Meckel, 1968; Schroeder, 1969, Egelberg, 1970; Kleinberg, 1970; Socransky, 1970; Gibbons and van Houte, 1973).
And, there are two intraoral processes, those are, microbial colonization and mineralization processes. It iss ure that plaque are concerned in periodontal inflammation by endotoxins, enzymes, and antigens; in caries by acid production: and in calculus formation with mineralization.
This study was dealt with oral flora and inorganic constituents of dental plaque of 279 Korean women:
1) Oral examination by the recommanded criteria of W.H.O.
2) Dental plaqnes of low right canine and first molor of each subject were collected and were cultured on the plate, of blood agar, nutrien agar, eosin methylene blue(E.M.B.) agar, sabouraud's media and bromcresol purple(B.C.P.) media in an aerobic condition. The specimen was also cultured anaerobically in thioglycollate broth medium and on blood agar plate in Torbal jar. On the other hand, direct smear were obtained and stained by gram and acid-fast staining.
3) On blood agar those were cultured anaerobically and aerobically, colony countings were done for the total viable count.
4) Attaching the alminium foils on the lingual surfaces of ower central incisors for 1, 2, 3, 5, 10 and 15-days, measured their weight. Then, dried for three hours in 110β. for the measurement of Ca, Mg, K, and Zn, the quantity was analysed by the atomic absoption spectrometry, Model 303 of Perkin-elmer Co.. And the
measurement of phosphorus was done by Fiske-Subba-row method.
5) For the electron microscopic study, the following processes had done: fixation of plaque at 4β with 3% glutaraldehyde and osmium tetroxide solution; dehydration with alcohol and propylene oxide; embedding(Epon 812); ultrathin section of 500βΌ600A; staining of uranyl acetate and lead citrate; and observation with
electron microscope(Hitachi, HU-11, E-1 type).
The results obtained in this study were as follows:
1.l Prevalence of dental caries of the subject was 91.9%, while the control group reveals 83.3%.
2. In identification of microflora isolated from dental plaque(N=279), 127 cases(45.1%) were identified. Bacterioides sp.(9.8%), Straphylococcus(9.1%), Streptococcus(7.1%) are found as predominant species; and the unidentified 170 cases could be classify into species only morphologically. Among them the gram
negative bacillus, long and thin from were in 52 cases(17.5%), short and coccoid from in 47 cases(15.8%); and unidentified of gram positive bacilli in 25 cases(8.4%).
3. The total viable count of the anaerobic and aerobic culture reveals increasing with the age of deposit day by the eleventh day except the fifty day. The count of the eleventh day was 27.0Γ10**7 cell/ml and 12.5Γ10**7 cell/ml of aerobic
cultivation. After the fifteenth day it decreased to 1.4Γ10**7 cell/ml and 1.5Γ10**7 cell/ml respectively.
4. The analysis of inorganic constituents of dental plaque which were obtained from alminium foils showed increasing tendency with the age of deposit day, especially by fifth day. Calcium, magnessium, potasium, zinc, and phosphorus are increased. Ca/P ratios of 1, 2, 3, 5, 10, and 15 day were 1.00, 1.11, 1.80, 1.80, 1.70, and 1.67.
5. Of electron microscopic finding, nummerous microorganisms were found in early stage. However, after two weeks, especially after five weeks, crystal-like substance, those are, needle-shaped crystal and platelet-sharped crystal revealed obviously as other investigators reported.restrictio
ν΄μ λ¬Ό λ΄ ν©νλ¬Ό, μ€κΈμ λλκ° μ΄λ§€ν¨λ₯μ λ€λͺ¨λ₯μ μ²΄λ΄ μ€κΈμ μΆμ (Cd, Ni,Zn)μ λ―ΈμΉλ μν₯
Thesis (master`s)--μμΈλνκ΅ λνμ :ν΄μνκ³Ό,1998.Maste
μμνκ°λλ₯Ό μ΄μ©ν μ©μ ꡬ쑰물μ κ· μ΄ν κ²°ν¨μ λν 건μ μ± νκ°
νμλ
Όλ¬Έ(μμ¬)--μμΈλνκ΅ λνμ :μ¬λ£κ³΅νλΆ,2002.Maste
μ κΈ°κΈμ ννκΈ°μμ¦μ°©λ²μ μν λΉνννλ λͺ¨μ μμ μ±μ₯λ C-doped GaAsAlGaAs λ° μμμ μ νΉμ±μ°κ΅¬
Thesis (doctoral)--μμΈλνκ΅ λνμ :물리νκ³Ό,1997.Docto
How strategic rivalries impede the emergence of balance of power : the case of Eastern Europe between the World Wars, 1919-1939
νμλ
Όλ¬Έ(μμ¬) --μμΈλνκ΅ λνμ :μΈκ΅νκ³Ό,2009.8.Maste
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