On distance estimates and atomic decompositions in spaces of analytic functions on strictly pseudoconvex domains

Milo\v s Arsenovi\'c,Romi F. Shamoyan 대한수학회 2015 대한수학회보 Vol.52 No.1

We prove some sharp extremal distance results for functions in various spaces of analytic functions on bounded strictly pseudoconvex domains with smooth boundary. Also, we obtain atomic decompositions in multifunctional Bloch and weighted Bergman spaces of analytic functions on strictly pseudoconvex domains with smooth boundary, which extend known results in the classical case of a single function.

Yugoslav (Serbian) Oral Tradition

Nada Miloš,ević,-Đ,orđević 한국외국어대학교 동유럽발칸연구소 2003 동유럽발칸연구 Vol.11 No.2

본 논문은 주로 부크 스테파노비치 까라지치(Vuk Stefanović Karadžić)에 의해 집성된 구 비서정시와 구비서사시, 그리고 또 다른 갈래들에 대한 최초의 체계적인 채록집이 출판된 15세기로부터 19세기에 이르는 시기의 구비전승에 대한 개괄을 기술한다. 구비서정시는 가부장적 문화의 요소가 살아 있는, 매우 오래된 시대적 관점의 숨겨진 층 위를 가진 복합적인 구비전승양식으로 간주된다. 구비서정시가 개인적인 감정과 소망을 표 현한다고 생각됨에도 불구하고, 단도직입적인 감정의 표현은 거의 드문 편이다. 이에 대한 설명은 문화와 집단적 표현간의 상호의존에서 찾아질 수 있다. 얼마간의 극단적으로 섬세한 시가들은 여성들에게 강요된 모든 억압들을 드러내기도 하며, 따라서 시가들은 가장 적합한 외적 심상을 선택해야만 하고, 고도로 발달된 詩作法의 실재를 통해서 감정의 메시지를 구 체화해야만 한다. 동시에, 심리학적으로 중요한 기능을 가진 가공하지 않은 행위예술을 참고 해야만 한다. 코소보에 관한 구비서사시가 모든 개개인이 자신의 국가에 속한다는 사실과 국가를 향한 기사로서의 의무를 깨닫게 되었을 때 나타났다는 것은 본 논문에서 지적되었다. 밀로슈 오 빌리치(Miloš Obilić)에 의한 터키의 술탄 무라드(Murad)의 죽음은 역사적인 행위로써 애국 적인 것이었으며, 이는 자신의 국가를 위해서 자신을 희생한다는 밀로슈의 내적 필요에 의 해 유발된 것이었다. 이는 부크 브랑코비치(Vuk Branković)의 비방과 자신으로부터 그것을 떨쳐버리려는 밀로슈의 욕구 사이에서 起因效果를 지닌 기사도적 구비서사시의 모티프방식 에 적합한 것이며, 따라서 군주인 라자르(Lazar)에 대한 자신의 충성심을 증명하는 것은 시 적 내용에 있어서 초기 구비서사시의 자극이 되었고, 전쟁의 비극적 결말을 제공하는 비방 자가 배신자로 되었다는 사실에 의해 확대된 것이다. 모든 시가는 개인적 감정과 영웅 서사시의 상호관계에 양식을 맞추고, 따라서 객관적인 역사 사건들은 모든 인물의 개인적 운명과 동일시된다. 반란에 대한 시가들 속에서 농민이라는 인물들은 자신들을 코소보에서 희생당한 귀족의 직접적인 자손으로 생각한다. 코소보 서사시와의 근접성은 문체적 표현접근에 의해 지속적 으로 이루어진다. 매우 풍부한 구비산문 역시 언급되어져야만 한다. 그것은 두 개의 기본적인 범주로 나뉘 어진다: 설화부분과 전설부분. 구비산문의 기본적인 특징은 문화적 특색을 보여주는, 갈래의 국제적인 체계에 맞춰져 있다.

Printing parameter optimization of PLA material concerning geometrical accuracy and tensile properties relative to FDM process productivity

Mihajlo Popović,Miloš Pjević,Aleksa Milovanović,Goran Mladenović,Miloš Milošević 대한기계학회 2023 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.37 No.2

High demand for part customization shifts industries toward AM technologies. Part customization in high-volume manufacturing is developed to its limits, whereas low-volume production using AM is still economically unjustified. FDM technology is quite common in lowvolume AM production, but the main issue is poor printing parameter optimization which may result in insufficient final part quality. The subject of this paper is the experimental determination of the optimal parameters for the PLA polymer FDM parts, focusing on nozzle temperature and printing speed. Part geometry and mechanical properties are evaluated for the temperature range of 170-210 °C and speeds of 40, 80, and 120 mm/min. Roughness measurements for part geometrical accuracy assessment and tensile tests for mechanical property estimation have shown the clear advantage of 190 °C and 40 mm/min over the other parameter combinations. However, for higher FDM process productivity 80 mm/min speed may also be considered with 190 °C.

Challenges of Public Administration Reform in Serbia: Between Requirements and Reality

Miloš Đinđić,Dragana Bajić 한국외국어대학교(글로벌캠퍼스) 러시아연구소 2018 REGION Vol.7 No.2

Informal systemic practices in Serbia embedded in the political and administrative milieu impair public administration reform efforts. Formal rules produce no real incentives for achieving effective reform outcomes and suppressing these informalities. External conditionality provides incentives as it puts pressure on institutional actors to pursue reforms, promising the often vague but important prospect of European Union membership. Although effective in initiating change in formal procedures, external incentives still fall short of deconstructing informal practices that circumvent written norms and standards, despite pressures and conditionality. In this paper, the authors argue that parallelism between formal rules that exist on paper, and reality, which is resistant to these same rules, results in a “reform faking” syndrome characterized by the acceptance of formal standards that the system finds difficult to absorb, despite internal and external demands to apply them. The paper goes on to argue that the embedded practice of fabricating reforms carries long-term consequences for system stability and the rule of law.

The influence of material infill on ABS-X flexural strength

Isaak Trajković,Aleksandra Dragičević,Ivana Medojević,Goran Mladenović,Miloš Milošević 대한기계학회 2023 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.37 No.11

This paper contains a comparison of the flexural strength results of two different samples. Both samples were made using additive manufacturing, from ABS (acrylonitrile butadiene styrene) material with the inclusion of an unknown filler designated as X. They also have in common that they are divided into two groups, the first group with a material infill of 100 %, and the second group with a material infill of 50 %. In order to determine that the material infill really affects the flexural strength results, the samples are differentiated by their shape. The first sample consists of tiles, while the second sample consists of pipes. The samples are printed vertically, which doesn't change the material's inherent mechanical qualities but does change the amount of infill and the strength of the bond between the layers. The difference between the values of the stress at failure of the material in the tile group is approximately 20 %, while in the tube group this difference is approximately 6 %. We can conclude that filling with the material in the range of 50 to 100 % during the production of pipes has an insignificant effect on bending strength, while this is not the case with plate samples. Based on this, there definitely is a significant influence of geometry when determining flexural strength. The idea for further research should be to measure the influence of samples treated with acetone on their flexural strength.

Xylella fastidiosa in Europe: From the Introduction to the Current Status

Vojislav Trkulja(Vojislav Trkulja ),Andrija Tomić(Andrija Tomić ),Renata Iličić(Renata Iličić ),Miloš Nožinić(Miloš Nožinić ),Tatjana Popović Milovanović(Tatjana Popović Milovanović ) 한국식물병리학회 2022 Plant Pathology Journal Vol.38 No.6

Xylella fastidiosa is xylem-limited bacterium capable of infecting a wide range of host plants, resulting in Pierce's disease in grapevine, citrus variegated chlorosis, olive quick decline syndrome, peach phony disease, plum leaf scald, alfalfa dwarf, margin necrosis and leaf scorch affecting oleander, coffee, almond, pecan, mulberry, red maple, oak, and other types of cultivated and ornamental plants and forest trees. In the European Union, X. fastidiosa is listed as a quarantine organism. Since its first outbreak in the Apulia region of southern Italy in 2013 where it caused devastating disease on Olea europaea (called olive leaf scorch and quick decline), X. fastidiosa continued to spread and successfully established in some European countries (Corsica and PACA in France, Balearic Islands, Madrid and Comunitat Valenciana in Spain, and Porto in Portugal). The most recent data for Europe indicates that X. fastidiosa is present on 174 hosts, 25 of which were newly identified in 2021 (with further five hosts discovered in other parts of the world in the same year). From the six reported subspecies of X. fastidiosa worldwide, four have been recorded in European countries (fastidiosa, multiplex, pauca, and sandyi). Currently confirmed X. fastidiosa vector species are Philaenus spumarius, Neophilaenus campestris, and Philaenus italosignus, whereby only P. spumarius (which has been identified as the key vector in Apulia, Italy) is also present in Americas. X. fastidiosa control is currently based on pathogen-free propagation plant material, eradication, territory demarcation, and vector control, as well as use of resistant plant cultivars and bactericidal treatments.

Printing orientation influence on tensile strength of PA12 specimens obtained by SLS

Ivana Jevtić,Zorana Golubović,Goran Mladenović,Filippo Berto,Aleksandar Sedmak,Aleksa Milovanović,Miloš Milošević 대한기계학회 2023 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.37 No.11

Selective laser sintering (SLS) is one of the additive manufacturing technologies dedicated to the production of high-quality parts with complex geometries. Here, polyamide 12 (PA12) is a commonly used material, for manufacturing parts with sufficient mechanical and thermal properties. In SLS, many manufacturing parameters have an effect on the mechanical properties of final parts. Even the decision regarding the orientation of a part in a powder bed may have a significant effect on the mechanical properties. In this research, the influence of horizontal (H) and vertical (V) printing orientations on the ultimate tensile strength (UTS) of fabricated PA12 specimens are examined. Our research findings show that H specimens exhibit larger deformations and smaller UTS value scatter in comparison with V specimens. Also, worth pointing out is the fact that V-oriented specimens have a higher elastic modulus. One can assume that the sintering process is more effective in V specimens, due to a more uniform laser beam trajectory than in the H specimens’ case.

Manufacturing parameter influence on FDM polypropylene tensile properties

Aleksa Milovanović,Zorana Golubović,Snežana Kirin,Tomáš Babinský,Ivo Šulák,Miloš Milošević,Aleksandar Sedmak 대한기계학회 2023 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.37 No.11

Polypropylene (PP) is a relatively new material in fused deposition modeling (FDM) technology. The main feature of this material is its ability to significantly elongate under applied load, unlike any other thermoplastic material used in FDM technology. Not much research has been conducted on this FDM material so far, hence, the subject of this paper is the investigation of printing parameters’ influence on PP tensile properties. Targeted parameters are layer height, infill density, and the orientation of raster lines, resulting in four different manufacturing regimes. To have a better insight into the experimental results, the data are analysed using ANOVA statistical method with Tukey HSD post hoc test. Obtained statistical results have proven the printing parameter’s influence on tensile results, emphasizing the influence on elastic modulus. Here, Tukey test results show the maximal number of homogeneous subsets evidencing that all printing parameters have an influence on elastic modulus values.

Functional and Environmental Advantage of Cleaning Ti5B1 Master Alloy

Aleksandar Mitrašinović,Miloš Tomić 한국정밀공학회 2022 International Journal of Precision Engineering and Vol.9 No.3

One of the greatest environmental goals for the aluminum alloys industry is generating higher quality products by introducing cleaner input materials while maintaining low production costs. A typical dilemma for the master alloy producers is the cleanness level of the master alloy since insoluble inclusions could serve as inoculants during the solidification process. In this work, commercial Ti5B1 master alloy is used for grain refinement of Al7Si4Cu aluminum alloy and compared with the cleaned master alloy that contained a lower amount of residual refractory oxides and salts. Metallography analysis was used for grain size measurement while Computer Aided Cooling Curve Analysis was used for assessment of the undercooling and heat release values. In all instances, specimens treated with the cleaned master alloy showed smaller grains in the final structure and lower undercooling values. The difference in released heat between liquidus and recalescence temperatures was about 25% in specimens where added 0.66 wt% of cleaned master alloys compared to specimens where the commercial master alloys were added. Using cleaner Ti5B1 master alloy with a higher number of TiAl 3 and TiB 2 particles improves its grain refi nementefficiency and transmits fewer impurities in produced parts. Producing cleaner master alloy would be beneficial from economic and environmental aspects by increasing its value and service time of produced parts besides simplifying the recycling process at the end of parts life-cycle.

Design and performance of low-pressure reversible axial fan with doubly curved profiles of blades

Živan Spasić,Miloš Jovanović,Jasmina Bogdanović-Jovanović 대한기계학회 2018 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.32 No.8

Reversible axial fans are used to achieve air (gas) flow in both directions. An axial fan only has an impeller that can achieve the reverse flow by changing the direction of the impeller rotation. In order to obtain the same performance for both directions, the profiles of the impeller blades should be completely symmetrical, in the shape of the ellipse. This paper presents the design and performance for a reversible axial fan with blades that have a slightly doubly curved profile. The shape of the profile, whose design is shown here, was previously obtained on the basis of the numerical simulation in the profile cascade. For the experimental tests, an axial reversible fan model with double curved profiles of the blades was made. Fan performance was obtained by testing a fan for three blade positions on a standard test installation. The performance curves were compared with the performance of the reversible axial fan blades with straight profiles. The fan with doubly curved profile blades achieved a greater increase in pressure and flow than the fan with straight profiles, with approximately the same efficiency. Low pressure axial reversible fans are used in drying chambers for wood and such a design can achieve higher drying efficiency.