• Journal of the Society of Naval Architects of Korea
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• v.48 no.1
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• pp.76-83
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• 2011

FCAW(Flux Cored Arc Welding) is a widely used welding method in shipbuilding. It also conducts WPS(Welding Procedure Specification) requested by the classification variations of the factors which affect the quality on the welded area such as thickness of base metal, type of welding wire and shielding gas etc. which has to be satisfied. CO2 is commonly used as a shielding gas for FCAW due to the economic point of view. The amount of shielding gas is stated when classification certify WPS. However, the shielding gas is unnecessarily used at the shipyard leaning only on the welder's experience as there are classification standards for using the shielding gas. It causes production cost to rise. Also recently, CO2 is a main contributor for global warming, and large amounts of CO2 are discharged into the atmosphere during shipbuilding processes without any filtration. Therefore it was confirmed by the security of the welded area as a result of conducting the destructive and non-destructive tests with setting up the factors and the standards by using the Taguchi method. Then the FCAW shielding gas's amounts were calculated precisely when assembling a ship. It will be applied to cost reduction and prevention of environmental pollution at the shipyard.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.37 no.7B
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• pp.586-594
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• 2012

The drastic growth of mobile communication and spreading of smart phone make the significant attention on Location Based Service. The one of most important things for vitalization of LBS is the accurate estimating position for mobile object. Focusing on AP's probabilistic position estimation, we develop an AP distribution map and new pattern matching algorithm for position estimation. The developed approaches can strengthen the advantages of Radio fingerprint based Wi-Fi Positioning System, especiall on the algorithms and data handling. Compared on the existing approaches of fingerprint pattern matching algorithm, we achieve the comparable higher performance on both of average error of estimation and deviation of errors. Furthermore all fingerprint data have been harvested from the actual measurement of radio fingerprint of Seoul, Kangnam area. This can approve the practical usefulness of proposed methodology.

• Proceedings of the Korea Water Resources Association Conference
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• 2019.05a
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• pp.185-185
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• 2019

Sustaining future wheat production is challenged by anthropogenically forced climate warming and drying led by increased concentration of greenhouse gases all around the globe. Warming stresses, originating from the elevated $CO_2$ concentration, are continuously reported to have negative impacts on wheat growth and yield. Yet, elevated $CO_2$ concentration, despite being disparagingly blamed for promoting warming, is also associated with a phenomenon called $CO_2$ enrichment; in which wheat yield can improve due to the enhanced photosynthesis rates and less water loss through transpiration. The conflicting nature of climate warming and $CO_2$ enrichment and their interplay can have specific implications under different environments. It is established form the field and simulation studies that the two contrasting phenomena would act severely in their own respect under arid and semi-arid environments. Wheat is a dietary staple for masses in Pakistan. The country's wheat production system is under constant stress to produce more from irrigated agricultural lands, primarily lying under arid to semi-arid environments, to meet the rapidly growing domestic needs. This work comprehensively examines the warming impacts over wheat yield and water productivity (WP), with and without the inclusion of $CO_2$ enrichment, under semi-arid environment of Punjab which is the largest agricultural province of Pakistan. Future wheat yields and WPs were simulated by FAO developed AquaCrop model v 5.0. The model was run using the bias-correction climate change projections up to 2080 under two representative concentration pathways (RCP) scenarios: 4.5 and 8.5. Wheat yield and WPs decreased without considering the $CO_2$ enrichment effects owing to the elevated irrigation demands and accelerated evapotranspiration rates. The results suggested that $CO_2$ enrichment could help maintain the current yield and WPs levels during the 2030s (2021-2050); however, it might not withhold the negative climate warming impacts during the 2060s (2051-2080). Furthermore, 10 - 20 day backward shift in sowing dates could also help ease the constraints imposed by climate warming over wheat yields and WPs. Although, $CO_2$ enrichment showed promises to counteract the adverse climate warming impacts but the interactions between climate warming and $CO_2$ concentrations were quite uncertain and required further examination.

• The KIPS Transactions:PartD
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• v.14D no.3 s.113
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• pp.311-318
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• 2007

A wearable computer has appeared as the next generation computer with the development of embedded system technique in our country, although it has not been applicable well since the hardware and software capabilities are limited for multimedia service. We have implemented a MPEG-4 video player to provide with such multimedia application service using the embedded systems. This paper illustrates the development of MPEG-4 video player operating on the wearable computer named WPS(Wearable Personal Station), the wristwatch PC developed at ETRI.

• Advances in environmental research
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• v.5 no.2
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• pp.141-151
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• 2016

Large amounts of aluminum hydroxide ($Al(OH)_3$) exist in water purification sludge (WPS) because of the added aluminum coagulant in water treatment process. Notably, $Al(OH)_3$ is an amphoteric compound, can be dissolved in its basic condition using sodium hydroxide to form aluminate ions ($Al(OH)_4{^-}$). However, in a process in which pH is increasing, the humid acid can be dissolved easily from WPS and will inhibit the recovery and reuse of the dissolved aluminate ions. This study attempts to fix this problem by a novel approach to separate $Al(OH)_4{^-}$ ions using nanofiltration (NF) technology. Sludge impurity in a alkaline solution is retained by the NF membrane, such that the process recovers $Al(OH)_4{^-}$ ions, and significantly decreases the organic matter or heavy metal impurities in the permeate solution. The $Al(OH)_4{^-}$ ion is an alkaline substance. Experimental results confirm that a recovered coagulant of $Al(OH)_4{^-}$ ion can effectively remove kaolin particles from slightly acidic synthetic raw water.

• The KIPS Transactions:PartB
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• v.13B no.5 s.108
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• pp.561-568
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• 2006

WPS(Wearable Personal Station) for next generation PC can define as a core terminal of 'Ubiquitous Computing' that include information processing and network function and overcome spatial limitation in acquisition of new information. As a way to acquire significant dynamic gesture data of user from haptic devices, traditional gesture recognizer based on desktop-PC using wire communication module has several restrictions such as conditionality on space, complexity between transmission mediums(cable elements), limitation of motion and incommodiousness on use. Accordingly, in this paper, in order to overcome these problems, we implement hand gesture recognition system using fuzzy algorithm and neural network for Post PC(the embedded-ubiquitous environment using blue-tooth module and WPS). Also, we propose most efficient and reasonable hand gesture recognition interface for Post PC through evaluation and analysis of performance about each gesture recognition system. The proposed gesture recognition system consists of three modules: 1) gesture input module that processes motion of dynamic hand to input data 2) Relational Database Management System(hereafter, RDBMS) module to segment significant gestures from input data and 3) 2 each different recognition modulo: fuzzy max-min and neural network recognition module to recognize significant gesture of continuous / dynamic gestures. Experimental result shows the average recognition rate of 98.8% in fuzzy min-nin module and 96.7% in neural network recognition module about significantly dynamic gestures.

• Korean Journal of Remote Sensing
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• v.31 no.6
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• pp.561-570
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• 2015

Till now, applications of many kinds of satellite images have been accentuated in the datacentric scientific studies, researches regarding system development and concerned technologies for them are on the un-matured stage. Especially, satellite image processing requires large volume data handling and specific analysis functionalities, so that practical necessity of base study for system development is emphasized on. In the view of information system, various edged trends such as web standards, cloud computing, or web framework are utilized owing to their application benefits proven and business needs. Considered these aspects, a testing implementation was carried out using OpenStack cloud computing environment and e-government framework. As for the processing functions, WPS in GeoServer, as one of OGC web standards, was applied to perform interoperable data processing scheme between two or more remote servers. Working with the server implemented, client-side was also developed using several open sources such as HTML 5, jQuery, and OpenLayers. If it is that completed further experiments onsite applications with actual multi-data sets and extension of on-demand functionalities with the result of this study, it will be referred as an example case model for complicated and complex system design and implementation which needs cloud computing, geo-spatial web standards and web framework.

• Proceedings of the KIEE Conference
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• 2005.10b
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• pp.216-218
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• 2005

This paper present a new approach to a noise robust recognizer for WPS interface. In noisy environments, performance of speech recognition is decreased rapidly. To solve this problem, We propose the recognition system using vocal-cord signal instead of speech. Vocal-cord signal has low quality but it is more robust to environment noise than speech signal. As a result, we obtained 75.21% accuracy using MFCC with CMS and 83.72% accuracy using ZCPA with RASTA.

• Journal of the Society of Naval Architects of Korea
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• v.51 no.6
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• pp.548-555
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• 2014

As a considerable, experimental approach, an Auto-carriage type of $CO_2$ welding machine and a MIG(Metal Inert Gas) welding robot under inert gas atmosphere were utilized in order to realize Al 5083 welding applied to hull and relevant components of green Al leisure ships. This study aims at investigating the effect of welding conditions(current, voltage, welding speed, etc) on thermal deformation that occurs as welding operation and tensile characteristics after welding, by using Al 5083, non-ferrous material, applied to manufacturing of co-environmental Al leisure ships. With respect to welding condition to minimize the thermal deformation, 150A and 16V at the wire-feed rate of 6mm/sec were acquired in the process of welding Al 5083 through an auto carriage type of $CO_2$ welding feeder. As to tensile characteristics of Al 5083 welding through a MIG welding robot, most of tensile specimens showed the fracture behavior on HAZ(Heat Affected Zone) located at the area joined with weld metal, except for some cases. Especially, for the case of the Al specimen with 5mm thickness, 284.62MPa of tensile strength and 11.41% of elongation were obtained as an actual allowable tensile stress-strain value. Mostly, after acquiring the optimum welding condition, the relevant welding data and technical requirements might be provided for actual welding operation site and welding procedure specification(WPS).

• Proceedings of the Korean Society of Computer Information Conference
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• 2015.01a
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• pp.67-70
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• 2015

특정 인터넷 서비스는 그 성격에 따라 제한된 위치에서만 서비스를 제공하도록 설계한다. 이러한 시스템 구조에서 사용자의 위치정보는 서비스 접근을 통제하는 과정에서 핵심적으로 사용되며 LSB(Location Based Service), WPS(Wifi Positioning System)와 같은 기술로 제안되었다. 그러나 기존 인증 기법은 대상이 일정하지 않은 불특정 다수의 사용자가 접근하기에 적합하지 않고, 서비스 공급자의 무선 AP를 이용하기 때문에 과도한 서버 부하에 취약하다. 따라서 본 논문에서는 이러한 문제를 해결하기 위해서 Beacon을 이용한 위치기반 인증 시스템을 제안한다. Beacon이란 Bluetooth 기술을 기반으로 근거리 무선 통신 기기이다. 사용자가 서비스 접근 권한을 획득하기 위해 인증 서버에서 요구하는 인증 코드는 BLE(Bluetooth Low Energy)를 사용하는 Beacon이 브로드캐스팅한다. 즉, 사용자는 Beacon이 BLE로 브로드캐스팅한 데이터를 수신할 수 있는 물리적인 범위까지 접근해야 인증 절차를 수행할 수 있다.