• Geotechnical Engineering
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• v.13 no.4
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• pp.121-134
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• 1997

Vibrations induced by traffic loading and construction activities are extremely important due to their potential to cause damage to adjacent structures and toy complaints to the neighbors. Vibration induced damage to the built environment may be caused by the direct transmission of vibrations as well as by the, vibration induced differential settlement. In order to effectively control the vibration related problems, the accurate in-situ vibration monitoring is essential. In this paper, a calibration technique of a geophone which is widely used in practice was described. Once the frequency characteristics of individual geophones were calibrated, the 3fomponent geophone was developed for the in-depth vibration measurement, and the dot ailed calibration and application techniques of the 3fomponent geophone were described. Vibrations caused by blasting, train loading, and pile driving were measured and the applicability of the 3fomponent geophone was assessed.

• Journal of Korean Society for Quality Management
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• v.48 no.1
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• pp.87-105
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• 2020

Purpose: This paper aims to propose a practical strategy for smart factories and a step-by-step quality strategy according to the maturity of smart factory construction. Methods: The characteristics, compositional requirements, and diagnosis system are examined for smart factories through theoretical considerations. Several cases of implementing smart factory are studied considering the company maturity level from the aspect of the smartness concept. And specific quality techniques and innovation activities are carefully reviewed. Results: The maturity level of smart factory was classified into five phases: 1) ICT non-application, 2) basic, 3) intermediate 1, 4) intermediate 2, 5) advanced level. A five-step quality strategy was established on the basis of case studies; identify, measure, analyze, optimize, and customize. Some quality techniques are introduced for step-by-step implementation of quality strategies. Conclusion: To build a successful smart factory, it is necessary to establish a quality strategy that suits the culture and size of the company. The quality management strategy proposed in this paper is expected to contribute to the establishment of appropriate strategies for the size and purpose of the company.

• Journal of the Institute of Electronics Engineers of Korea CI
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• v.46 no.2
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• pp.106-113
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• 2009

Recently, due to many industrial accidents at construction sites, a variety of researches for structural health monitoring (SHM) of buildings are progressing. For real site application of SHM, one of the advanced technologies has blown as wireless sensor networks (WSN). In this paper, we proposed WIVA(WSN Monitoring framework based on 3D Visualization and Augmented Reality in Mobile Devices) system that applies 3D visualization and AR technology to mobile devices with camera based on WSN in order to expand the extent of information can observe. Moreover, we performed experiments to validate effectiveness in 3D and AR mode that utilize WSN data based on IEEE 802.15.4. In real implementation scenario, we demonstrated a fire occurrence test in 3-story building miniature.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.35 no.6B
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• pp.970-976
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• 2010

Platform convergence originated from the convergence of broadcast and telecommunication is making rapid progress including IT and not-IT fields in order to provide a variety of converged services, S/W eco-system construction, and so on. With the advent of convergence environment, IEEE 802.15.4-based RF4CE technology is rising because of creating momentum for the market using converged connectivity between home and office devices as well as all around located devices. In this paper, we present enhanced RF4CE key seed distribution approach in order to provide efficient connection and control between devices. The proposed approach consists of device mutual authentication, initial vector assignment, and two-phase key seed distribution. Moreover, we make a development real RF4CE test board and its key agreement simulator to verify the proposed approach.

• Elastomers and Composites
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• v.46 no.1
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• pp.10-21
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• 2011

Recently, with developments in the automotive industry, sound and vibration damping have a considerable attraction with a diversified customer needs and advanced automobile. In general, among various materials, textile materials, such as felt and glass fibers, polyurethane foam, and PET fiber materials were used to reduce sound and vibration of the automobile. These materials were located in various main parts of the automobile to block sound and vibration, resulting in a comfortable ride. In addition, to improve fuel economy, weight reduction and cost saving for the automobile were also being considered together as well as the reduction of sound and vibration of the automobile. Therefore, in this paper, we focused on the need of interior sound and vibration absorption materials in the automobile and absorption materials-related technologies.

• Spatial Information Research
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• v.23 no.2
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• pp.59-68
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• 2015

According to the NGIS (National Geographic Information System) project conducted since 1995, the central and local government has been accumulating huge amount of geospatial data. Korean Ministry of Land, Infrastructure and Transport started its GeoSpatial open platform (V-World) service in January 2012, also offering a wide range of functions and services. However, the National GeoSpatial open platform is still woefully deficient for the users to find their desired data, lack of data for private business area, insufficient in publicity of local government and public-private partnerships. Through analyzing current research trend after GeoSpatial open platform served for three years, study on overseas expansion, system links, service improvement, utilization and future strategy has been mainly conducted. This study, by analyzing the advanced overseas GeoSpatial platform as well as domestic research trend and combining the concept of new technology, business platform and SMG (Seoul Metropolitan Government)'s GeoSpatial platform, proposes a policy for the construction of future GeoSpatial Open Platform model.

• Journal of Korea Water Resources Association
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• v.42 no.3
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• pp.259-270
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• 2009

The applicability of the developed distributed rainfall runoff model using a multi-directional flow allocation algorithm and a real-time updating algorithm was evaluated. The rainfall runoff processes were simulated for the events of the Andong dam basin and the Namgang dam basin using raingauge network data and weather radar rainfall data, respectively. Model parameters of the basins were estimated using previous storm event then those parameters were applied to a current storm event. The physical propriety of the multi-directional flow allocation algorithm for flow routing was validated by presenting the result of flow grouping for the Andong dam basin. Results demonstrated that the developed model has efficiency of simulation time with maintaining accuracy by applying the multi-directional flow allocation algorithm and it can obtain more accurate results by applying the real-time updating algorithm. In this study, we demonstrated the applicability of a distributed rainfall runoff model for the advanced basin-wide flood management.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.41 no.9
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• pp.1010-1019
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• 2016

The K-user multiple-input single-output broadcast channel is considered under per-antenna power constraints, i. e., each transmit antenna must satisfy its own power constraints. A low complexity zeroforcing(ZF) precoder is proposed when the number of transmit antennas M is greater than K. The proposed precoder design significantly reduces computational complexity for the precoder construction while attaining the sum spectral efficiency close to that achievable by the optimal ZF precoder.

• Journal of the Korean association of regional geographers
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• v.4 no.2
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• pp.139-150
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• 1998

Recently in connection with the development of network technology, GIS researches shift their focuses to openGIS which enables to share heterogeneous geodata and geoprocessing resource under the environment of LAN and WAN. This study proposes an easy method to develope GUIs which enables openGIS in the intranet environment. In the developing stage of GUI, the most important thing is to develop effective windows programming technique and apply a internet linking technique to developed GUIs. This study shows an internet linking technique and a GUI developing method using OLE automation and ActiveX/COM standards. Using a case study of Taegu City Library, the study constructs a GIS database and develops its GUI which performs map overlaying, referencing attribute tables, drawing up of thematic map, buffer analysis, and statistical calculations. This study remains same further research areas of developing a new advanced technique for openGIS and its GUI using distributed object model of CORBA, Java language, and JDBC data accessing technique.

• Environmental Engineering Research
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• v.10 no.3
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• pp.138-143
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• 2005

Laboratory batch experiments were conducted to evaluate the Fenton degradation rates of phenanthrene. Fenton reactions for the degradation of phenanthrene were carried out with aqueous and slurry phase, to investigate the effects of sorption of phenanthrene onto solid phase. Various types of surfactants and electrolyte solutions were used to evaluate the effects on the phenanthrene degradation rates by Fenton's reaction. A maximum 90% removal of phenanthrene was achieved in aqueous phase with 0.9% of $H_2O_2$ and 300 mg/L of $Fe^{2+}$ at pH 3. In aqueous phase reaction, inhibitory effects of synthetic surfactants on the removal of phenanthrene were observed, implying that surfactant molecules acted as strong scavenger of hydroxyl radicals. However, use of $carboxymethyl-{\beta}-cyclodextrin$ (CMCD), natural surfactant, showed a slight enhancement in the degradation of phenanthrene. It was considered that reactive radicals formed at ternary complex were located in close proximity to phenanthrene partitioned into CMCD cavities. It was also show that Fenton degradation of phenanthrene were greatly enhanced by addition of NaCl, indicating that potent radical ion ($OCI^-$) played an important role in the phenanthrene degradation, although chloride ion might be acted as scavenger of radicals at low concentrations. Phenanthrene in slurry phase was resistant to Fenton degradation. It might be due to the fact that free radicals were mostly reacting with dissolved species rather than with sorbed phenanthrene. Even though synthetic surfactants were added to increase the phenanthrene concentration in dissolved phase, low degradation efficiency was obtained because of the scavenging of radicals by surfactants molecules. However, use of CMCD in slurry phase, showed a slight enhancement in the phenanthrene degradation. As an alternative, use of Fenton reaction with CMCD could be considered to increase the degradation rates of phenanthrene desorbed from solid phase.