• Korean Journal of Computational Design and Engineering
• /
• v.9 no.2
• /
• pp.102-111
• /
• 2004

In this paper, the efficient layout method for generating common and continuous cutting path of flat-bar profile. The ‘flat -bar’ is a stiffener and has long rectangular shape. This paper describes a fast nesting algorithm of the flat-bar, and a procedure to generate cutting path of gas/plasma torch, which is operated by a NC (numerically controlled) gas/plasma cutting machine. By using this common and continuous path, the machining-time for cutting and the maintenance-cost of plasma-torch could be reduced. Proposed procedures are written in C-language and applied to the Interactive Flat-Bar-Nesting System executable on Open VMS with X-Window system.

• Journal of KIISE:Computer Systems and Theory
• /
• v.33 no.1_2
• /
• pp.44-51
• /
• 2006

In this paper, we present a network-based integrated nesting system, that is adapted a current engineering concept. Generally, sheet cutting processes proceed in turn following an existing order In this study, however, the special characteristics of these processes were analyzed and the processes were redesigned with distributed design so that they could be operated in a client/server environment. Also, the necessary sheet material cutting processes, part CAD, nesting, part CAM, and NC post-processor capabilities, were implemented so that many workers could handle them all on the Web. Compared to existing commonly used systems, the developed system can provide integrated work environment for cutting automation, allow job collaboration between workers, and it has proved that it can shorten the standby time for work. By grafting computer system technologies to sheet material cutting automation field, this research expects to contribute to the enhancement of factory automation efficiency and productivity.

• Special Issue of the Society of Naval Architects of Korea
• /
• 2013.12a
• /
• pp.35-41
• /
• 2013

Nowadays, automated modeling system for steel margin based on interactive user interface has been developed and applied to the production design stage. The system could increase design efficiency and minimize human error owing to recent CAD technique. However, there has been no approach to the pre-nesting design stage at all in early modeling process especially where ship model should be handled at more than two design stages using AVEVA Marine. A designer of the design stage needs artificial intelligence system beyond modeling automation when 3D model must be prepared in early modeling process using AVEVA Marine because they have focused on 2D nesting traditionally. In addition, they have a hard time figuring out the model prepared in previous design stage and modifying the model for steel purchase size in early modeling process. In this paper, artificial intelligence modeling system for automated application of steel margin in early modeling process using AVEVA Marine is developed in order to apply to the pre-nesting design stage that can detect effective segments before a calculation to find if a segment locates near block butt boundaries by filtering noise segments among lines, curves and surface intersections based on IT big data analysis.

• Korean Journal of Computational Design and Engineering
• /
• v.2 no.3
• /
• pp.195-210
• /
• 1997

In Rapid Prototyping process, the time required to build multiple prototype parts can be reduced by packing several parts optimally in a work volume. Interactive arrangement of the multiple parts is a tedious process and does not guarantee the optimal placement of all the parts. In this case, packing is a kind of 3-D nesting problem because parts are represented by STL files with 3-D information. 3-D nesting is well known to be a problem requiring an intense computation and an efficient algorithm to solve the problem is still under investigation. This paper proposes that packing 3-D parts can be simplified into a 2-D irregular polygon nesting problem by using the characteristic of rapid prototyping process that the process uses 2-dimensional slicing data of the parts and that slice of the STL parts are composed of polygons. Our algorithm uses no-fit-polygon (NFP) to place each slice without overlapping other slices in the same z-level. The allowable position of one part at a fixed orientation for given parts already packed can be determined by obtaining the union of all NFP's that are obtained from each slice of the part. Genetic algorithm is used to determine the order of parts to be placed and orientations of each part for the optimal packing. Optimal orientation of a part is determined while rotating it about the axis normal to the slice by finite angles and flipping upside down. This algorithm can be applied to any rapid prototyping process that does not need support structures.

• Korean journal of applied entomology
• /
• v.41 no.4
• /
• pp.263-267
• /
• 2002

A faunistic survey was conducted to find Osmia bees to be used as an effective pollinator in apple orchards. Collections were carried out from more than 50 selected sites in mountainous areas throughout Korea for 3 years (1996-98) with providing bundle of bamboo traps (6-8 mm of inner diameter) as Osmia nesting site. Five species of Osmia ：O. cornifrons (Radoszkowsky), O. pedicornis Cockerell, O. taurus Smith, O. satoi Yasumatsu et Hirashima and O. jacotti Cockerell, were collected at the rates of 39.9-51.7, 28.3-53.7, 5.5-19.1, 0.8-0.9 and 0.0-0.1%, respectively. And O. cornifrons and O. pedicornis were the dominants with over 80% of total Osmia collected through the collections. Out of those bees collected, rates of female were 29-43% for O. cornifrons. 10-12% for O. pedicornis and 22-43% for O. taurus. When the collection sites of the dominant 3 species were grouped in relation to altitudes above the sea level, about 50% or more bees were collected form the higher sites (500m or higher) while 20% or less were from the lower sites (200m or lower). When the bamboo traps were placed at the same sites continuously for 3 years, number of O. cornrfrons and O. taurus collected was slightly increased while that of O. pedicornis was drastically decreased year after year. Nesting by Osmia bees seems to have started at around early April, peaked at early May and ended by Mid June, while nest competing species of Sphecidae and Eumenidae started nesting at around early June, peaked at early July and ended by the Mid August.

• Proceedings of the IEEK Conference
• /
• 2006.06a
• /
• pp.717-718
• /
• 2006

In this paper, we present an RTOS named HEART (Highly Expandable AOP-based Real-Time operating system). It is modularized into a single base and multiple optional features. The base implements a core functionality and each feature implements a specific functionality of RTOS such as interrupt nesting, multithreading, inter-thread communication, and etc. Users can customize HEART just by selecting needed features. Then a specialized version of HEART is automatically generated. We argue that HEART enables the rapid construction of optimized and application-specific RTOSes for diverse embedded systems.

• IE interfaces
• /
• v.21 no.1
• /
• pp.131-140
• /
• 2008

To shorten product development time and cost, integrated information managements of product, manufacturing process and resource are essential. In the area of material addressing, process engineers should make their decisions in the manner of collaborative engineering in order to reduce the manufacturing preparation time and cost in the product development and production. A digital virtual factory which is an united digital model of entire factory could be very useful for these areas. In this paper, the digital virtual factory is constructed and used for material addressing and analysis of an automotive general assembly shop. We developed the material addressing system for automotive general assembly shops using digital virtual factory models and nesting algorithms, and applied it to realistic problems of a Korean automotive company as an convenient and effective way of material addressing.

• Proceedings of the Korean Society for Technology of Plasticity Conference
• /
• 2003.05a
• /
• pp.283-287
• /
• 2003

In recent years, design of an optimal blank shape is very important for sheet metal forming process in the automobile industry because the raw material cost rate is significant part in the automobile industry. With the design of an optimal blank shape, the engineer can protect a blank from an excessive holding force to improve the quality and reduce the ratio of material scrap. Therefore design of an optimal blank shape is inevitable in sheet metal forming process. However, if it causes a complicated shape of blank, it may be difficult to do the blank layout optimally. In this study, we developed software of optimal blank layout connected with the software of optimal blank shape design which was created in the past by the present authors. And by using these softwares, we would like to present the method in order to get optimal utilization ratio easily and precisely within short time for the sequence of works from design to blank layout.

• Journal of Korean Society for Atmospheric Environment
• /
• v.19 no.1
• /
• pp.13-23
• /
• 2003

A local wind model and a three dimensional local environmental model including advection, diffusion, deposition. and photochemical reactions were performed at Gwangyang Bay, Korea, to predict air flow and air pollutants concentrations. A large grid was used, and nesting method was employed for small grid calculation. From the meterological module simulation, we were able to reproduce local wind characteristics such as sea/land winds and mountain/valley winds simulation at Gwangyang Bay. In addition, the concentration module showed high concentration regions at Yosu industrial complex, Gwangyang steel company. and Container anchor. It was also seen that air pollutants were dispersed by sea/land winds. A comparison between the measurement and the prediction of sulfur dioxide and nitric oxide, which are relatively low-reacted pollutants, was performed. However, the measured nitrogen dioxide and ozone concentrations were higher than the simulated ones. Particularly, ozone concentration between 8 a..m. and 8 p.m. agreed well, but the measured ozone during the rest of time were generally higher.

• Journal of Environmental Impact Assessment
• /
• v.18 no.3
• /
• pp.123-129
• /
• 2009

In Korea the population of breeding house swallow is continuously decreasing. In this regard this study was conducted to find out the overall population trend during 2001-2005. The areas of urban and rural sites were separated to estimate population. Also the sites in Yangpyung areas were chosen to compare population density between two sites during Mar-Aug, 2006. The house swallow had two breeding periods and I tried to correlated amount of days of incubation and number of eggs in the nest. After egg hatching the homing behavior also was estimated assuming lack of foods takes longer to bring foods back to the nest. This study signified that a long term study should be conducted for population change and spring arrival time due to climate change in Korea.