• Title/Summary/Keyword: Two-stage expansion

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A Study on the BIM Application in Architecture Design Phase - Focus on BIM(Building Information Modeling) Process for Schematic Design- (건축설계에서 BIM(Building Information Modeling) 적용에 관한 연구 -계획설계 BIM(Building Information Modeling) 프로세스를 중심으로-)

  • Min, Young-Gi;Lee, Jae-Kook
    • Journal of The Korean Digital Architecture Interior Association
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    • v.11 no.4
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    • pp.29-38
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    • 2011
  • In this study, neighborhood facility and office building to target two cases were performed BIM process. In the initial design phase of the planning process was conducted for the BIM process modeling, BIM in the design stage while performing the required range and level of the process were studied. Accordingly, from architectural firms to leverage BIM process, the proposed methods, efficient use of the modeling process proposed. Quality management information and input for the modeling and design process should be determined from the initial design and construction, including, for each field should be considered BIM, which require an appropriate range of information, according to these requirements, BIM creation and expansion of the level of information should be clearly defined. Perform the procedure for BIM in the process of communicating with stakeholders is critical. In addition, the input data and output data needed to perform management and to perform at the level obtained BIM design process and the model should be clear.

Measurement during Construction of Nakdong Bridge by Incremental Launching Method (낙동강교 ILM 가설에 따른 시공 중 계측)

  • Kim, Hyung-Tae;Cho, Nam-So;Jung, Ji-Man;Yang, Sung-Man
    • Proceedings of the KSR Conference
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    • 2007.11a
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    • pp.575-580
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    • 2007
  • As the volume of traffic in southern part of the republic of Korea grew, expansion of transportation was required. In that purpose, the railway between Samnangjin and Gwangyang is being extended to a double-track line. This construction includes Nakdong bridge located across Nakdong river. This truss bridge is constructed in incremental launching method (ILM) and composed of two sections, straight line and curved one. Bridge construction in the method goes with the shift of roller supports which results in the change of structural system. To accomplish safe construction, the measurement during the whole launching stages. The locations of member in severe condition and the corresponding response values were estimated through the preliminary construction stage analysis. Based on the analysis, the measurement during construction was planned. Several sensors and measurement devices were installed at appropriate locations. During the whole launching stages, the measurement was performed and the corresponding data were monitored and stored in real time. The comparison of the responses from the analysis and the measurement showed no indication of yielding of the structural members. Consequently, the construction of Nakdong bridge was concluded to be relevant.

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A Composition and Basis Experiment of Single Cylinder Low Speed Diesel Engine for Atkinson Cycle Materialization (앳킨슨사이클 실현을 위한 단기통 저속 디젤기관의 구성과 기초 실험)

  • Jang, Jtaeik
    • Transactions of the Korean hydrogen and new energy society
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    • v.24 no.5
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    • pp.461-466
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    • 2013
  • In this research, the diesel cycle was thermodynamically interpreted to evaluate the possibility of high efficiency by converting diesel engine to the atkinson cycle, and general cycle features were analyzed after comparing these two cycles. That an experimental single cylinder and a long stroke diesel-atkinson engine, of which S/B ratio was more than 3, were manufactured. After evaluating the engine through basic experiments, a diesel engine was converted into the atkinson cycle by constituent VCR (variable compression ratio) device and VVT (variable valve timing) system. The experimental method was to observe compression work reduction effects due to low compression effects from delayed intake valve closing of the early stage atkinson engine. The result, the possibility of increasing compression ratio about each engine load was confirmation by constructing compensate expansion-compression ratio in accordance with the delayed intake valve close.

Reversible Data Hiding Using a Piecewise Autoregressive Predictor Based on Two-stage Embedding

  • Lee, Byeong Yong;Hwang, Hee Joon;Kim, Hyoung Joong
    • Journal of Electrical Engineering and Technology
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    • v.11 no.4
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    • pp.974-986
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    • 2016
  • Reversible image watermarking, a type of digital data hiding, is capable of recovering the original image and extracting the hidden message with precision. A number of reversible algorithms have been proposed to achieve a high embedding capacity and a low distortion. While numerous algorithms for the achievement of a favorable performance regarding a small embedding capacity exist, the main goal of this paper is the achievement of a more favorable performance regarding a larger embedding capacity and a lower distortion. This paper therefore proposes a reversible data hiding algorithm for which a novel piecewise 2D auto-regression (P2AR) predictor that is based on a rhombus-embedding scheme is used. In addition, a minimum description length (MDL) approach is applied to remove the outlier pixels from a training set so that the effect of a multiple linear regression can be maximized. The experiment results demonstrate that the performance of the proposed method is superior to those of previous methods.

A Feasibility Study of Wood-plastic Composite Paver Block for Basic Rest Areas

  • Yang, Sungchul
    • Journal of the Korean Wood Science and Technology
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    • v.47 no.1
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    • pp.51-65
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    • 2019
  • A wood-plastic composite (WPC) paver block was manufactured using wood chips waste through an extrusion process, and it was intended to be used for paving in basic rest areas. The first stage in this study covered preliminary tests in terms of flexural strength and dimensional swelling to determine the optimal WPC compounding mix condition, by variation of the WPC ingredients. Next, three different paver blocks including the WPC block, a non-porous cement block, and a porous cement block were tested in terms of various material properties in the laboratory. Finally, two outdoor test sections of the proposed paver blocks were prepared to simulate a basic rest area. Test results indicated that the flexural strength of the WPC paver blocks was about 1.6 times greater than that of the tested cement paver blocks. The WPC block pavement was unaffected by water buoyance as well as volume expansion due to swelling. Results from the impact absorbance test and light falling weight deflectometer (LFWD) test clearly showed that the WPC block paving system marginally satisfied the comfortable and safe hardness range from the pedestrians' perspective, while the results demonstrated that it is structurally sound for application as a road paving block.

Development and Effectiveness of a University Student Coaching Program Using Metaverse Space (메타버스 공간을 활용한 대학생 코칭 프로그램 개발과 효과)

  • Kyoung A Kim;Hui-Jeong Yun;Jieun Kim
    • Human Ecology Research
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    • v.61 no.3
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    • pp.445-458
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    • 2023
  • This study aims to develop and implement a coaching program in the metaverse space to address issues faced by university students during their life stage and verify their effectiveness. The overall program consists of four sessions: "Opening," "Metaverse-based Coaching Clinic (2 sessions)," and "Coaching Clinic Reflection and Feedback." A total of 20 participants were selected through S University's extracurricular program system. To assess the effectiveness of the program, surveys, as well as focus group interviews (FGIs) were conducted. Using SPSS 26.0, significant differences were observed in the participants' career decision self-efficacy and resilience. The FGIs were conducted with a total of four participants divided into two groups, with each group lasting for one hour. The analysis revealed key phases, including the introductory phase comprising participants' motivation and expectations, the main phases consisting of program operation, coaching perception and outcomes, metaverse environment, and metaverse coaching perception and outcomes, as well as the concluding phase in which recommendations are suggested for subsequent programs. The study confirmed the significant impact of coaching in the metaverse space and highlighted the maximization of coaching effectiveness through mutual anonymity facilitated by avatars. This research holds significance as an exploratory study that practically verifies the potential expansion of the metaverse environment in the coaching field.

A study on Management Strategy of Italian Hotel Restaurant in Korea (국내호텔 이태리식당 경영전략에 대한 연구)

  • 추상용
    • Culinary science and hospitality research
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    • v.6 no.1
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    • pp.57-78
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    • 2000
  • In the 21st century the size of sales of food service business in Korea will be 30 trillion won which means Food service business in Koreas is a mega market, but it is only quantitative growth and might face the limit of growth. At the same time it is predicted that from the academic world Food service business will develop endlessly after IMF condition. Of course I hope so as a member of national. Al though I propose that quantitative side is important, qualitative side must not be disregarded the present and future customer is needs should be met because the 1st goal of company is to achieve a management goal and pursuit profit. The present situation requires a peculiar and specific strategy of its own which can not be followed by competing hotels so that value can be created and buying intention can be occurred after buying. Until now the goal of marketing campaign has been transacted marketing just for closing a transaction, but it must be related marketing which is seeking mutual interests of customer and company. The strategies to attain these goals are : 1) to change from products and service management-focused to customer management and relationship building-focused. 2) to establish a core strategy which needs to be changed from market occupancy of volume expansion to customer occupancy. 3) to change from one-way communication to two-way communication. 4) to change from large scale marketing by company dimension to small scale marketing by sections. If companies focus on core benefit and augmented service to be sought by customers and make every efforts to create a value customer occupancy will increase automatically, the reduction of marketing cost will be followed, and marketing efforts will be much more efficient. In introducing a new product it is still easier to diffuse through the existing customers, and also important market information can be obtained from customers using this close relationship. If this close relationship maintains well customers will say even a trivial inconvenience and complaint and propose an idea of new product. Kotler divides relationship marketing into 5 stages such as Basic, Reactive, Accountable, Proactive, and Partnership. From the 1st stage to the last stage customer management is absolutely important and also in management strategy. The last stage, Partnership can come into the stage which is actively participated in service development and problem solving by customers. so more loyal customers have more successful performance the company attain.

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Occurrence of Phytophthora Root Rot of Atractylodes macrocephala in field contitions (포장조건에 따른 백출의 역병 발생)

  • Cho, Joon-Hyeong;Kim, Yong-Wook;Park, Chun-Geon;Bang, Kyong-Hwan;Seong, Nak-Sul
    • Korean Journal of Medicinal Crop Science
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    • v.9 no.3
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    • pp.211-219
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    • 2001
  • The disease incidence rates of Phytophthora root rot of A. macrocephala caused by P. drechsleri were dramatically increased in two distinctive periods at experimental fields of National Crop Experiment Station(NCES), Suwon, in 1999 and in 2000 ; one was in the period of 30 to 45 days old seedling stage in spring and the other was just after heavy rainy season in late summer or in early fall. The disease was occurred at seedling stage under the conditions of ${{\geq}15^{\circ}C}$ of average temperature with ${{\geq}100mm}$ rainfalls for 20 days and the tendencies were similar in both year. By the disease, rhizome propagated field was more damaged(18.6%) than seed propagated field(56.0%). Comparing the disease incidence rates at five different fields in Suwon, Youngju and Andong, the damages at soil improving fields and non-mulching fields were less severe than those at continuous cropping fields without soil improvement and mulching fields and occurrence. Expansion of the disease were seemed to be highly related with the populations of P. drechsleri in soils depend on the cultivation method and field conditions. Although the populations of the pathogen in soils collected from Andong and Youngju, in which rhizome were continuously propagated for two and three years respectively, were comparably less than that from Suwon, in which rhizome were propagated for one year, however, the damages by the disease were more severe in Andong and Youngju. So, two or more years of cultivation at the same field may not be useful for Atractylodes plants..

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Effect of Intake Flow Control Method on Part Load Performance in SI Engine(1) - Comparison of Throttling and Masking (스파크점화기관에서 흡기제어 방식이 부분부하 성능에 미치는 영향(1) - 스로틀링과 마스킹의 비교)

  • Kang, Min Gyun;Ohm, Inyong
    • Transactions of the Korean Society of Automotive Engineers
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    • v.22 no.2
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    • pp.156-165
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    • 2014
  • This paper is the first investigation on the effect of flow control methods on the part load performance in a spark ignition engine. For comparison of the methods, two control devices, port throttling and masking, were applied to a conventional engine without any design change of the intake port. Steady flow evaluation shows that steady flow rates per unit opening area and swirl ratio are very low compared with the port throttling and saturated from mid-stage valve lift, however, swirl increases slightly as the lift is higher in case of 1/4 masking control. In the part load performance, the effect of simple port throttling on lean misfire limit expansion is limited and insufficient; on the other hand a masking improves the limit considerably without any port modification for increasing swirl. Also the results show that the intake flow control improves the combustion with following two mechanisms: stratification induced by the combination of the flow pattern and the fuel injection timing attribute to ignition ability and the intensified flow ensure fast burn. In addition fuel consumption reduces under the flow controls and the reduction rate is different according to the operation conditions and control methods. At the Stoichiometric and/or low speed and low load the throttling method is more advantageous; however vice versa at lean and high load condition. Finally, the throttling is more efficient for HC reduction than masking, on the other side the NOx emissions increase under the masking and decrease under the port throttling compared with conventional port scheme.

Thermal Deformation Analysis of a Scroll Compressor for Automobile according to the Change of Materials (소재변경에 따른 차량용 스크롤압축기의 열변형 해석)

  • Lee, Hyoungwook;Lee, Geunan;Kim, Jeongbae
    • Journal of the Korean Solar Energy Society
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    • v.34 no.6
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    • pp.67-74
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    • 2014
  • An inverter scroll compressor is used for the air conditioning in cars. Scrolls would be changed from the aluminum material to the magnesium material in order to satisfy the light weight trends of cars. The material changing influences on the scroll dimensions particularly the gap between two scrolls. Since the larger gap declines the performance of the compression, the gap between wraps of scrolls or the gap between wraps of scrolls to the plate of the opposite scroll is regarded as an important design variable. This paper is focused on the effects of the thermal stress due to the materials changing. The temperature difference between the inlet and the outlet is about 60 degrees and the highest operating temperature in the compressor is less than 110 degrees. The level of thermal stresses in the magnesium scroll is less than the result from aluminum one. The trend of the deformation is revealed that the normal directional deformation is 2 times lager than the in-plane directional deformation. Therefore the gap between the top of the wrap to the plate of the opposite scroll become more important than the other gaps. The orbiting scroll deforms larger than the fixed scroll by the thermal stresses. The deformation of the magnesium scroll is about 10% lager than that of the aluminum scroll. This value is similar to the ratio of the coefficients of thermal expansion of two materials. At the initial design stage, the results give many useful guides to engineers to propose gaps between parts.