• Journal of Information Processing Systems
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• 제17권5호
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• pp.989-1003
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• 2021

With the recent increase in the types of services provided by Internet companies, collection of various types of data has become a necessity. Data collectors corresponding to web services profit by collecting users' data indiscriminately and providing it to the associated services. However, the data provider remains unaware of the manner in which the data are collected and used. Furthermore, the data collector of a web service consumes web resources by generating a large amount of web traffic. This traffic can damage servers by causing service outages. In this study, we propose a website search engine that employs a system that controls user information using blockchains and builds its database based on the recorded information. The system is divided into three parts: a collection section that uses proxy, a management section that uses blockchains, and a search engine that uses a built-in database. This structure allows data sovereigns to manage their data more transparently. Search engines that use blockchains do not use internet bots, and instead use the data generated by user behavior. This avoids generation of traffic from internet bots and can, thereby, contribute to creating a better web ecosystem.

• International Journal of Computer Science & Network Security
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• 제21권9호
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• pp.247-260
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• 2021

Data modeling is a process of developing a model to design and develop a data system that supports an organization's various business processes. A conceptual data model represents a technology-independent specification of structure of data to be stored within a database. The model aims to provide richer expressiveness and incorporate a set of semantics to (a) support the design, control, and integrity parts of the data stored in data management structures and (b) coordinate the viewing of connections and ideas on a database. The described structure of the data is often represented in an entity–relationship (ER) model, which was one of the first data-modeling techniques and is likely to continue to be a popular way of characterizing entity classes, attributes, and relationships. This paper attempts to examine the basic ER modeling notions in order to analyze the concepts to which they refer as well as ways to represent them. In such a mission, we apply a new modeling methodology (thinging machine; TM) to ER in terms of its fundamental building constructs, representation entities, relationships, and attributes. The goal of this venture is to further the understanding of data models and enrich their semantics. Three specific contributions to modeling in this context are incorporated: (a) using the TM model's five generic actions to inject processing in the ER structure; (b) relating the single ontological element of TM modeling (i.e., a thing/machine or thimac) to ER entities and relationships; and (c) proposing a high-level integrated, extended ER model that includes structural and time-oriented notions (e.g., events or behavior).

• 한국인터넷방송통신학회논문지
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• 제19권1호
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• pp.127-132
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• 2019

본 논문에서는 유비쿼터스 컴퓨팅에 의한 농수산물의 생장관리에 필요한 정보시스템을 설계하고 구축하였다. 그러기 위하여 여러 센서 시스템을 설치하고 IP Cam을 개발하여 모니터링을 구축하였다. 이러한 모니터링에 의한 농수산물의 생육조건을 직접 제어하고 관리하는 데이터베이스에 의해 IT 기술에 의한 환경관리시스템을 구축할 수 있었다. 이를 위하여 생육조건을 취합하고 실시간으로 데이터를 획득할 수 있는 여러 센서를 설치하였으며 IP Cam을 세부분으로 나누어 설계하고 제작하였으며 농수산용으로 적용함으로써 토양수분, 온도조절, 환경정보 등 각종정보를 모니터링하여 최적의 생육환경조건을 마련할 수 있었다.

• Geomechanics and Engineering
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• 제30권5호
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• pp.437-448
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• 2022

Alluvial soil is challenging to work with due to its high compressibility. Thus, consolidation settlement of this type of soil should be accurately estimated. Accurate estimation of the consolidation settlement of alluvial soil requires accurate prediction of compressibility parameters. Geotechnical engineers usually use empirical correlations to estimate these compressibility parameters. However, no attempts have been made to develop correlations to estimate compressibility parameters of alluvial soil. Thus, this paper aims to develop new models to predict the compression and recompression indices (Cc and Cr) of alluvial soils. As part of the study, geotechnical laboratory tests have been conducted on large number of undisturbed samples of local alluvial soil. The obtained results from these tests in addition to available results from the literature from different parts in the world have been compiled to form the database of this study. This database is then employed to examine the accuracy of the available empirical correlations of the compressibility parameters and to develop the new models to estimate the compressibility parameters using the nonlinear regression analysis. The accuracy of the new models has been accessed using mean absolute error, root mean square error, mean, percentage of predictions with error range of ±20%, percentage of predictions with error range of ±30%, and coefficient of determination. It was found that the new models outperform the available correlations. Thus, these models can be used by geotechnical engineers with more confidence to predict Cc and Cr.

• 한국지리정보학회지
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• 제8권1호
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• pp.23-39
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• 2005

위성 통신 기술의 발달로 국부적으로 수행되던 위치 추적의 범위가 전 세계로 확산되었다. 하지만 기존의 물류 관제 시스템들은 관제 서버와 물류간의 통신을 위하여 휴대폰 통신망을 이용하기 때문에 일부 지역 내에서 이동하는 물류에 대해서만 관제가 가능하다. 이 논문에서는 위성 통신을 이용하여 전 세계를 이동하는 물류 매체인 냉동 컨테이너의 위치 및 상태 정보를 관리하기 위한 시스템을 제안하였다. 제안 시스템은 냉동 컨테이너의 상태를 직접 관제하는 데이터 수집부, 관제 서버와의 통신을 담당하는 위성 통신부, 냉동 컨테이너 정보를 관리하는 관제부로 구성된다. 시스템의 관제부에서는 냉동 컨테이너의 위치 추적 및 관제를 효과적으로 수행하기 위하여 기존의 TB 트리를 기반으로 하는 다중 버전 이동 객체 색인을 사용하였다. 제안된 냉동 컨테이너 관제시스템은 화주, 운송회사 등 육해상 물류관련 기관에서 냉동컨테이너 및 선박 위치추적, 컨테이너 통제, 컨테이너 통계 등 다양한 용도로 사용될 수 있어 화주에게는 컨테이너 운송에 대한 서비스를 제공하며, 선사에게는 선박안전경보시스템, 선박 관리, 냉동컨테이너를 효율적인 관리 기능을 제공하게 한다.

• 대한기계학회논문집
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• 제16권1호
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• pp.31-40
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• 1992

본 연구에서는 CAD 시스템의 테이터구조로 부터 특성을 추출하여 CAPP 시스템 의 입력으로 사용되는 형상특징을 자동적으로 인식하고 형상특징의 관련정보를 생성하 는 형상특징인식시스템을 개발하는데 있다. X.Y.Z 축에 수직인 평면들로 구성되는 비회전형상부품을 대상으로 하여, 주로 밀링작업과 연관이 있는 관통슬롯, 막힌슬롯, 관통스텝, 막힌스텝, 포켓의 5가지 형상특징을 자동적으로 인식하는데 특히 X.Y.Z축에 수직인 평면들로 구성되고 내부에 볼록 부위가 업는 형상 특징을 대상으로 한다. CAD시스템은 AutoCAD를 사용하여 퍼스널 컴퓨터에서 시스템을 개발한다.

• 한국생산제조학회지
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• 제18권3호
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• pp.261-269
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• 2009

Micro end-milling process is applied to fabricate precision mechanical parts cost-effectively. It is a complex and time-consuming job to select optimal process conditions with high productivity and quality. To improve the productivity and quality of precision mechanical parts, micro end-mill wear and cutting force characteristics should be studied carefully. In this paper, high speed machining experiments are studied to construct the optimum process design as well as the mathematical modeling of tool wear and cutting force related to cutting parameters in micro ball end-milling processes. Cutting force and wear characteristics under various cutting conditions are investigated through the condition monitoring system and the design of experiment. In order to construct the cutting database, mathematical models for the flank wear and cutting force gradient are derived from the response surface method. Optimal milling conditions are extracted from the developed experimental models.

• 한국기계가공학회지
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• 제11권1호
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• pp.101-106
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• 2012

The press bulging process is very useful and productive method to produce round-type mechanical components which have not been able to be manufactured because of limitation of the conventional press technology. The application of the press bulging process has expanded very quickly in the hydraulic and electronic industry and more recently it has been used to produce other mechanical parts such as the automobile and shipping parts. This expanding application also has brought some unsolved problems and leads many researchers to put their effort into the die design of the press bulging process. In this study, to obtain the optimum die shape for the press bulging process, various process parameters have been considered such as corner radius, bulging height, pressing length, and forming load, etc. The main interest of this paper is to verify the press bulging process which has more than 4.0 in height-length ratio. From this aspect, Finite Element analysis shows great ability to simulate the precise deformation process and gives us manufacturing database. Consideration of strain, stress, and strain-rate for the various cases has been also taken to keep the forming load within a particular range.

• 한국CDE학회논문집
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• 제5권2호
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• pp.103-112
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• 2000

CAD databases are the core element to the management of product information. A key to the successful use of the databases is a rational method of query to and retrieval from the databases. Although it is parts geometry that users eager to retrieve from the CAD databases, no system yet supports geometry-based query. This paper aims at developing a new method of assessing geometric similarity which can serve as the basis of geometric query for CAD database. The proposed method uses ASVP (Alternating Sums of Volumes with Partitioning) decomposition that is a volumetric representation of a part obtained from its boundary representation. A measure of geometric similarity between two solid models is defined on their ASVP tree representations. The measure can take into account overall shapes of parte, shapes of features and their locations. Several properties that a similarity measure needs to satisfy are discussed. The geometric query developed in this paper can be used in a wide range of applications using CAD databases, which include similarity-based design retrieval, variant process planning, and components selection from part library. An experiment has been carried out to demonstrate the effectiveness of the method, and the results are presented.

• 한국정밀공학회지
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• 제20권12호
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• pp.115-125
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• 2003

The design methodology of plastic injection molding die has been gradually moved from two-dimensional line drawings to three-dimensional solid models. The 3D design gives many benefits, a few of which are: ease of design change, data associativity from concept design to final assembly. In the paper represented is the implementation of a program which automatically generates 3D mold-bases and cooling-lines, conforming to given geometric constraints. It utilized a commercial CAD software and the related API(application program interface) libraries. We constructed a DB(database) of typical mold-bases assembled from standard parts, from which the geometry (position & dimension) of a mold-base and composed parts can be automatical]y determined by a few key parameters. Also we classified cooling lines into several typical types and constructed a DB, from which the position of cooling lines is automatically determined. The research is expected not only to simplify construction of a 3D mold-base model including cooling lines but also to reduce design efforts, by way of databases and automatized determination of geometric dimensions.