• 천문학회보
• /
• 제39권2호
• /
• pp.46-46
• /
• 2014

Interactions such as mergers and flybys play a fundamental role in shaping galaxy morphology. We used the Horizon Run 4 cosmological N-body simulations to study the frequency and the type of halo interactions as a function of the environment, the separation p, the mass ratio q, and the target halo mass. We defined targets as haloes more massive than 10^11 Msun/h, and a target is interacting if it is located within the virial radius of a neighbour halo more massive than 0.4 times the target mass. We find that the interaction rate as a function of time has a universal shape for different halo mass and large-scale density, with an increase and saturation. Larger density yield steeper slopes and larger final interaction rates, while larger masses saturate later. Most interactions happen at large-scale density contrast ${\delta}$ about 10^3, regardless of the redshift. We also report the existence of two modes of interactions in the (p,q) plane, reflecting the nature (satellite or main halo) of the target halo. These two trends strongly evolve with redshift, target mass, and large-scale density. Interacting pairs have similar spins parameters and aligned spins, with radial trajectories, and prograde encounters for non-radial trajectories. The satellite trajectories become less and less radial as time proceed. This effect is stronger for higher-mass target, but independent of the large-scale density.

• Advances in aircraft and spacecraft science
• /
• 제2권4호
• /
• pp.445-467
• /
• 2015

The paper presents some details of the CFD modeling of a novel design where jet ignition devices replace the traditional spark plugs for a faster and more complete combustion. The numerical simulations show how the pre-chamber jet ignition in a Wankel engine differs from reciprocating piston engine applications. The jets issuing from the jet ignition pre-chamber have many different speeds in the different directions as the pressure build-up at the trailing edge of the rotating chamber makes extremely fast the ignition of the chamber mixture in the direction of rotation. Conversely it prevents the jet ignition in the opposite direction. Careful positioning along the periphery and design of the connecting pipes and the prechamber volume with the help of CFD simulations permits to achieve extremely fast and complete combustion as impossible with spark plugs. The paper proposes results of CFD simulations of the combustion evolution within a jet ignited Wankel engine rotor, detailing challenges and opportunities of the application, as well as a first assessment of the impact the faster and more complete combustion permitted by jet ignition may have on the performances of Wankel engines for unmanned aerial vehicles applications.

• 한국언론정보학보
• /
• 제49권
• /
• pp.5-19
• /
• 2010

이 논문에서는 벤야민과 맥클루언의 복제와 전기라는 두 가지 개념을 토대로 하여 디지털 복제 시대 지식의 위상과 성격을 밝히고자 하였다. 복제와 전기는 디지털 시대 지식의 탈물질화를 해명하는 실마리이다. 탈물질화는 디지털 시대 지식의 기술적 조건으로서 그것이 갖는 현상 형태에 대한 이해의 실마리를 제공한다. 이 논문은 디지털 복제 시대의 변화된 기술적 사회적 조건이 무엇인지 분석하고, 그런 조건에서 지식이 어떤 모습을 갖게 되는가를 검토한다. 이를 위하여 기계 복제, 전자 복제, 디지털 복제의 차이점을 정보, 미디어, 지식의 상호관련 속에서 분석하였다. 이러한 연구의 의미는 디지털 복제 시대의 지식이 처한 기술적 사회적 조건을 밝힘으로써 향후 이에 대한 본격적인 논의의 출발점을 마련하는 데 있다.

• 한국실내디자인학회논문집
• /
• 제22권1호
• /
• pp.85-96
• /
• 2013

This study relates to meta-phenomena in architectural design. Among others, this study aims to interpret and demonstrate the cognitive thoughts and methodological systems in 'autonomy and instrumentality' presented in works of art by positivist architects focusing on diagrams after the second modernity in addition to earlier formal experiments by John Hejduk, Peter Eisenman, Bernard Tschumi, and Daniel Libeskind. In order to achieve these aims, this study approached the mimetic concepts developed by Walter Benjamin and Theodor Adorno. Especially, meta-phenomena in the methods of architectural design were connected to productivity in Adorno's mimetic concepts. Also, in terms of formation and creation of works of art, the mimetic backgrounds of Adorno's theories on aesthetics were identified from features of concepts on the part of formal experiments. The results were systemized methodologically based on meta-phenomena appearing in pure arts and overall architectural design. These were presented as a framework to interpret 'autonomy and instrumentality' that exist in the working of negativity and mimesis. In this way, logics and intuition in architectural design as well as methodological systemization of convergent creativity were proved valid. In conclusion, Adorno's mimetic concepts systemized based on negativity and critical awareness may lead to new concepts. It has been proved that it is valid for security of meta-phenomena of architectural design as a production of autonomous spaces for differences and creation.

• 대한족부족관절학회지
• /
• 제2권2호
• /
• pp.97-101
• /
• 1998

Primary subacute pyogenic osteomyelitis, or Brodie's abscess has received much attention since its initial documentation in the literature in 1832 by Sir Benjamin Brodie. Brodie's abscess is a localized form of chronic osteomyelitis that occurs most often in the metaphyseal area of the long bones of the lower extremities of young adults, Intermittent pain of long duration is the presenting complaint, along with local tenderness over the affected area. Laboratory evaluation is unrevealing, with a normal white blood cell count and differential count. The erythrocyte sedimentation rate may also be normal. Roentgenogram shows a markedly varied appearance and an abscess may be easily mistaken for various neoplasm. The most common organism cultured from abscess is Staphylococcus species. Treatment includes curettage of the lesion and administration of antibiotics. We present a case report (with a 1-year follow-up period), demonstrating the successful surgical treatment of Brodie's abscess of the distal metaphysis of the left tibia caused by Salmonella cholerasuis in a 33-year-0ld male who had no hemoglobinopathy.

• 정보저장시스템학회논문집
• /
• 제5권2호
• /
• pp.82-88
• /
• 2009

Understanding the adhesion behavior and characteristics of toner film is required to achieve image and text printing with high quality resolution. Toner can be considered as a thin film coating on a media such as paper or polymer film. Quantitative measurement of adhesion characteristics of the thin film is important to assess the reliability of the system. In this work the main objective was to investigate the adhesion characteristic between the toner and the media by ramp loading scratch test method. The scratch test may be used to obtain quantitative information about the adhesion of the film to the substrate. In the scratch test a diamond tip was used to scratch the surface of the toner film under an increasing normal load until the toner detached or fractured. The critical load (LC) was obtained from the experimental results. Also, the relationship between the critical load and the adhesive strength of the interface between the substrate and the toner was obtained by measuring the normal and tangential forces during the scratch test. Finally, theoretical analysis of the toner scratch characteristics was performed based on Benjamin and Weaver theory, Plowing model, and Laugier model.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
• /
• 제42권1호
• /
• pp.43-46
• /
• 2016

Ameloblastic carcinoma is a malignant form of ameloblastoma defined by histological evidence of malignancy in primary, recurrent, or metastatic tumor. Such a tumor is rare, and the maxilla is an unusual site. Due to its rarity, the characteristics of this tumor in the maxilla have not been well described. Case 1: A 55-year-old, ill-appearing Nigerian male presented to our center with left maxillary swelling of seven-year duration. The swelling had been slow-growing and painless until one year prior, when the growth became rapid and was coupled with severe pain. The swelling affected both oral function and facial esthetics, and the patient reported difficulty breathing. There was a maxillary, ulcerated swelling extending from teeth 12 to 18 and blocking the left nostril. The involved teeth were moderately mobile. Case 2: A 32-year-old male farmer presented with recurrent right maxillary swelling of six-year duration. Prior to this episode, he had undergone surgery for ameloblastoma (follicular type). The present swelling was fungating through the skin and protruding into the right nostril. Ameloblastic carcinoma is an aggressive odontogenic tumor that requires aggressive surgical treatment.

• Earthquakes and Structures
• /
• 제7권5호
• /
• pp.817-842
• /
• 2014

ASCE/SEI 41-13 provides modeling parameters and numerical acceptance criteria for various types of members that are useful for evaluating the seismic performance of reinforced concrete (RC) building structures. To accurately evaluate the global performance of a coupled wall system, it is crucial to first properly define the component behaviors (i.e., force-displacement relationships of shear walls and coupling beams). However, only a few studies have investigated on the modeling of RC coupling beams subjected to earthquake loading to date. The main objective of this study is to assess the reliability of ASCE 41-13 modeling parameters specified for RC coupling beams with various design details, based on a database compiling almost all coupling beam tests available worldwide. Several recently developed coupling beam models are also reviewed. Finally, a rational method is proposed for determining the chord yield rotation of RC coupling beams.

• Mycobiology
• /
• 제46권1호
• /
• pp.47-51
• /
• 2018

In the present study, the characterization and properties of silver nanoparticles from Yucca shilerifera leaf extract (AgNPs) were investigated using UV-visible spectroscopic techniques, zeta potential, and dynamic light scattering. The UV-visible spectroscopic analysis showed the absorbance peaked at 460 nm, which indicated the synthesis of silver nanoparticles. The experimental results showed silver nanoparticles had Z-average diameter of 729 nm with lower stability (195.1 mV). Additionally, our dates revealed that AgNPs showed broad spectrum antagonism ($p{\leq}.05$) against Fusarium solani (83.05%) and Macrophomina phaseolina (67.05%) when compared to the control after nine days of incubation. Finally, AgNPs from leaf extracts of Y. shilerifera may be used as an agent of biocontrol of microorganism of importance. However, further studies will be needed to fully understand the agronanotechnological potentialities of AgNPs from Yucca schidigera.

• Restorative Dentistry and Endodontics
• /
• 제42권3호
• /
• pp.240-252
• /
• 2017

The restoration of endodontic tooth is always a challenge for the clinician, not only due to excessive loss of tooth structure but also invasion of the biological width due to large decayed lesions. In this paper, the 7 most common clinical scenarios in molars with class II lesions ever deeper were examined. This includes both the type of restoration (direct or indirect) and the management of the cavity margin, such as the need for deep margin elevation (DME) or crown lengthening. It is necessary to have the DME when the healthy tooth remnant is in the sulcus or at the epithelium level. For caries that reaches the connective tissue or the bone crest, crown lengthening is required. Endocrowns are a good treatment option in the endodontically treated tooth when the loss of structure is advanced.