• 드라이브 ㆍ 컨트롤
• /
• 제19권2호
• /
• pp.1-10
• /
• 2022

Field robots operate in various areas, including construction, agriculture, forestry and manufacturing. Typical tasks of field robots used in various areas include excavation, flattening, and demolition. Such tasks are often accomplished in narrow alleys or indoors. In the case of field robots, there is a limit to working in a small space. Thus, to compensate for these shortcomings, many field robots equipped with Tiltrotators have recently been observed. The advantages of Tiltrotator are improved task efficiency and reduced operating time by reducing unnecessary behavior. We need simulation models that can improve the ability of new people to work and simulate tasks in advance. Thus, in this paper, we developed a simscape-based simulation model and modeling of 6DOF systems for field robots equipped with Tiltrotator. Dynamic modeling of field robot 3D models using Simcape multibody and hydraulic systems of field robots using Simcape Hydraulics were modeled. We applied a PID controller to create a control system that operates along the input angle. Simulation results show that errors occur when comparing input and output angles, but overall, they move along input angles.

• 대한건축학회논문집:계획계
• /
• 제34권11호
• /
• pp.113-123
• /
• 2018

First of all, the multi-story Housing applying resident's participation in europe was classified by the menu selection method, the two-step supply method and the cooperative method. And then I analyzed flexible unit plan of cases for deriving the planning methode and the characteristics of flexibility. First, I analyzed the area and form of the unit plan, structure and Installation, fixed and variable elements to derive the planning method. The area of units are distributed from a minimum of $35m^2$ to a maximum of $150m^2$, and many of the unit planes have a narrow front and a deep depth. The structure is a long-span wall-structure or a skeleton structure, and is designed without any columns and bearing walls in the interior space for flexibility in spatial composition. The vertical shafts are located in the center of the unit in a box-form or in the corner at the unit dividing wall for free placement of interior wall. Fixed elements are framework and facility systems. Most of the future residents in the two-steps supply method and the cooperative method were able to freely design the internal space within the zoning concept proposed by the architect and change the location of the facade element within module system proposed by the architect. Second, the characteristics of the flexibility applied to the unit plan were divided in integrated flexibility, functional flexibility, construction flexibility, and supply flexibility. The integrated flexibility enables residents to give the variable space combination based on the complex structure of the inner space for providing various living experiences. Regarding functional flexibility, the three-dimensional spatial structure with neutral space has multi-functionality according to the needs of residents and easily accepts mixing of hybrid programs such as work and residence. Constructive flexibility allows residents to create identity by freely planning interior space and changing the size or location of facade components in a determined system of architects. Finally, various types of size and space composition are proposed and realized in the whole building applying menu selection method, so that flexibility in the offer can accommodate and integrate various types of living.

• 한국해양공학회지
• /
• 제34권3호
• /
• pp.217-226
• /
• 2020

An offshore plant is an offshore platform that can process oil and gas resources in rough seas with a poor working environment. Moreover, it is a complex structure with different types of offshore facilities and a large amount of outfitting that connects different offshore installations. In particular, an enormous amount of various piping materials is installed in a relatively narrow space, and thus, the difficulty of working is relatively high compared to working in ships or ground plants. Generally, when the 3D detailed design is completed, an offshore plant piping process is carried out at the shipyard with ISO 2D fabrication drawings and ISO 2D installation drawings. If a worker wants to understand the three-dimensional piping composition in the working area, he can only use three-dimensional viewers that provide limited functionality. As offshore plant construction progresses, correlating work with predecessors becomes more complicated and rework occurs because of frequent design changes. This viewer function makes it difficult to identify the 3D piping structure of the urgently needed part. This study deals with the process support method based on a system using a 3D simulator to improve the efficiency of the piping process. The 3D simulator is based on the Unity3D engine and can be simulated by considering the classification and priority of 3D models by the piping process in the system. Further, it makes it possible to visualize progress information of the process. In addition, the punch content can be displayed on the 3D model after the pipe inspection. Finally, in supporting the data in relation to the piping process, it is considered that 3D-simulator-supported piping installing could improve the work efficiency by more than 99% compared to the existing method.

• 대한지역사회영양학회지
• /
• 제2권3호
• /
• pp.406-416
• /
• 1997

Teacher's satisfaction with school lunch programs run by foodservice(FS) management types were surveyed with questionnaire at 5 middle and 4 elementary schools. The 88 middle and 104 elementary school teachers who participated and schools' FS management were of 5 types : self/conventional, contracted/conventional, contracted/commissary and contracted/dosirak delivery. Most teachers knew correctly their schools' present FS management types and thoroughly understood the main reasons for needing school lunch program with proper nutrition, better taste and balanced diets in addition to the first reason its less work than preparing homelunches. Teacher's satisfactions with their present school FS were high in self/conventional and contracted/conventional and was very low in contracted/commissary and contracted/ dosirak Taste, hygiene, nutrition and dining facilities in turn were pointed out to be improved : firstly hygiene in the self and firstly taste in the contracted. Particularly dining-rooms were found to have narrow space, uncomfortable chairs and tables, unclean, and having unpleasant smells. Teachers observed that the overall students' food habits such as eating more various foods and better table manners through that school lunch programs, particularly the self-managed types were improved. Conclusively most teachers emphasized school lunch programs to be continued and preferred self-managed types and contracted/conventional types as the second best in having less work to manage, better, taste, nutrition and hygiene, less cost and better nutrition education in turn. And they thought school founders should handle the finances needed to newly establish or repair the school FD facilities, otherwise provided with the partial aid of student's parents.

• 한국항공우주학회지
• /
• 제37권11호
• /
• pp.1131-1139
• /
• 2009

연소불안정현상은 주로 음향파와 열방출률 섭동간의 상호작용에 의해 발생한다고 알려져 있다. 이러한 현상은 헬름홀츠 공진기와 같은 수동제어기를 사용하여 감소시킬 수 있다. 그러나 헬름홀츠 공진기는 일반적으로 좁은 주파수대역에 대해서만 효과가 있는 단점을 가진다. 따라서 본 연구에서는 다양한 작동 범위에서 효과를 가질 수 있도록 피스톤을 사용하여 헬름홀츠 공진기의 부피를 변화시켜가며 연소불안정현상에 적용하였다. 그 결과 피스톤을 최적 위치인 40mm에 동조시킴으로써 연소 불안정 모드의 진폭을 크게 감소시킬 수 있었다. 그리고, 연소기와 헬름홀츠 공진기 사이의 동압의 위상차가 흥미로운 관계에 있음을 나타내었다. 또한 헬름홀츠 공진식과 위상차를 이용한 능동적으로 동조되는 수동제어방식에 대해 알아보았다.

• 한국산업보건학회지
• /
• 제33권2호
• /
• pp.171-187
• /
• 2023

Objectives: Aircraft cabin cleaning work is characterized by being performed within a limited time in a narrow and enclosed space. The objective of this study was to evaluate the exposure levels to dust, ultra fine dust(PM2.5) and black carbon(BC) among aircraft cabin cleaners. Methods: Active personal air sampling for respirable dust(n=73) and BC(n=47) was conducted during quick transit cleaning(cabin general and vacuum-specific) and seat cover replacement and total dust and PM2.5 were area-air-sampled as well. Also, size distribution of particle was identified with the cleaning workers targeted. Dusts were collected with PVC filters using gravimetric analysis. The concentration of PM2.5 and the particle size distribution were measured with real-time direct reading portable equipment using light scattering analysis. The concentration of BC was measured by aethalometer(filter-based real-time light absorption analysis instrument). Results: The geometric mean of respirable dust was the highest at vacuum cleaning as 74.4 ㎍/m³, following by replacing seat covers as 49.3 ㎍/m³ and cabin general cleaning as 47.8 ㎍/m³ . The arithmetic mean of PM2.5 was 4.83 ~ 9.89 ㎍/m³ inside the cabin, and 28.5~44.5 ㎍/m³ outside the cabin(from bus and outdoor waiting space). From size distribution, PM_2.5/PM₁₀ ratio was 0.54 at quick transit cleaning and 0.41 at replacing seat covers. The average concentration of BC was 2~7 ㎍/m³, showing a high correlation with the PM2.5 concentration. Conclusions: The hazards concentration levels of aircraft cabin cleaners were very similar to those of roadside outdoor workers. As the main source of pollution is estimated to be diesel vehicles operating at airports, and it is necessary to replace older vehicles, strengthen pollutant emission control regulations, and introduce electric vehicles. In addition, it is necessary to provide as part of airport-inftastructure a stable standby waiting space for aircraft cabin cleaners and introduce a systematic safety and health management system for all workers in the aviation industry.

• 대한기계학회논문집A
• /
• 제36권3호
• /
• pp.289-295
• /
• 2012

최근에 들어 서비스 로봇의 효율성 향상을 위한 이동로봇에 대한 연구가 활발하다. 이동로봇은 서비스 로봇의 이동성을 향상시킴으로써, 다양한 공간에서 작업을 할 수 있도록 한다. 그러나 기존의 서비스 로봇은 높은 무게중심으로 인하여 작업 중 전복의 가능성이 높다. 또한, 이동로봇에 사용되는 바퀴는 작고 가벼우며, 환경에 따라 바퀴의 종류를 바꿔야 하므로 기존의 허브형 모터는 한계가 있다. 이를 해결하기 위하여 본 연구에서는 이동로봇에 적합한 허브형 구동모듈과 가변접지면 메커니즘을 개발하였으며, 전방향 이동로봇에 적용하였다. 이를 통해 이동성 및 안정성을 향상과 다양한 작업공간에서의 효율성 향상시켰다. 또한 다양한 시험을 통하여 제안한 메커니즘의 성능을 검증하였다.

• 건축역사연구
• /
• 제18권6호
• /
• pp.23-46
• /
• 2009

The history to have used lime in building construction was much long without distinction of the East or the West. The ancient nations of korean peninsula had used lime as construction material. The witness was discovered in the kings' tombs of fifth century. In the Joseon dynasty(15~19c), what applied several developed lime compounds to the kings' tombs have been recorded in 'Sanleong-Uigwe(山陵儀軌)' & 'Yeonggeon-Uigwe(營建儀軌)' of those days documents. Therefore, this paper is to examine the whole procedures from the product and provision of lime to its application through those days documents. Following conclusions have been reached through the study. Three lime compounds to be developed for the kings' tombs was extendedly applied to residential government buildings step by step within the current of time. These compounds to be used in the kings' tombs of the Joseon dynasty had been correlated to those of the ancient nations, which were nations of korean peninsula in narrow range, chinese and orient nations in broad range. These compounds have possibilities of development as the environmental-friendly building material. And these compounds should provide a standard specification for conservation & restoration of the traditional and cultural properties. I could confirm that the whole procedures had not been developed within limited space-time of the specified nation & period, but within interactions of the nations & periods. In the periods which disturb its interaction, the expansion of productivity in building construction was interfered.

• 천문학회보
• /
• 제40권2호
• /
• pp.28.3-29
• /
• 2015

$Ly{\alpha}$ nebulae, or "$Ly{\alpha}$ blobs", are extended (~100 kpc), bright (L[$Ly{\alpha}$] ~ 1044 erg/s) clouds of $Ly{\alpha}$-emitting gas. The origin of the $Ly{\alpha}$ emission remains unknown, but recent theoretical work suggests that measuring the polarization could discriminate among powering mechanisms. we will discuss current status of $Ly{\alpha}$ polarization observations at high-redshift and our on-going survey program. We will present the first narrow-band, imaging polarimetry of a $Ly{\alpha}$ blob, B3 J2330+3927 at z=3.09, with an embedded, radio-loud AGN (C. You et al. in prep.). The AGN lies near the blob's $Ly{\alpha}$ emission peak and its radio lobes align roughly with the blob's semi-major axis. With the SPOL polarimeter on the MMT telescope, we map the polarization in a grid of circular apertures of radius 0.6" (4.4 kpc), detecting a significant (>$2{\sigma}$) polarization fraction P% in 10 apertures and achieving strong upper-limits (as low as 2%) elsewhere. The degree of the polarization map increases from P% ~ 5% at ~5 kpc from the blob center to ~20% at the outer part (~30 kpc). The detections are distributed asymmetrically, roughly along the blob's major axis. The polarization angles (${\Theta}$) are mostly perpendicular to this axis. These results are consistent with the picture that $Ly{\alpha}$ photons produced at the AGN (or the host galaxy) are resonantly scattered away from the center. Higher polarization fraction on the radio jet suggests that the gas is more optically thin along the jet than the off-axis region.

• 건축역사연구
• /
• 제16권4호
• /
• pp.7-22
• /
• 2007

In San Francisco, two new museums were recently built in 1995 and 2005. The one is San Francisco Museum of Modern Art designed by Mario Botta and the other is De Young Museum designed by Jacques Herzog & Pierre de Meuron. The urban settings for the museums are compared with each other and theories of the architects are evolved on different branches in the modernist trends. The theories and settings are followed by the representation in the forms, facades, interior spaces and towers. SFMOMA is located on the SoMa area, which was recently developed into a cultural urban core with Moscone Center and Buena Yerba Garden. De Young Museum was rebuilt in the old museum site in the Golden Gate Park. The one is on the context of urban artefacts and the other on the context of natural artefacts. To Botta, the museum in today's city plays a role analogous to that of the cathedral of yesterday. It is a place of common encounter and confrontation. The volume of SFMOMA which is geometrical and symmetric with double pylons. The frontality on the street and public green open space and the axiality of SFMOMA runs through the Buena Yerba Garden over Buena Yerba Center for the Arts are reminded us of an urban core with a religious monument and a city square. The staircase with grandiose design in the atrium seems to work as an altar with lighting from skylight above enhancing the liturgical ambiance. De Young Museum is shaped in a rectangle with long narrow courtyards. Three bands of volumes are juxtaposed and the nature flows into the museum corridors and galleries. The tower is distorted so as to be aligned to the street grids of the surrounding area. The copper panel of De Young Museum and natural context evoke modern concept of "machine in the garden". The two museums from different pedigrees of Modern Architecture are now major landmarks of SF and urban expressions for the 21st century.