• The Journal of the Acoustical Society of Korea
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• v.18 no.3E
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• pp.9-20
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• 1999

To investigate the characteristics of internal waves (IWs) and their effects on acoustic wave propagation, a series of sea experiment were performed in the east coast of Donghae city, Korea in 1997 and 1998 where the water depth varies between 130 and 140 m. Thermistor strings were deployed to measure water temperatures simultaneously at 9 depths. CW source signals with the frequencies of 250,670 and 1000 Hz were received by an array of 15 hydrophones. Through the Wavelet transform analysis, the IWs are characterized as having typical periods of 2-17 min and duration of 1-2 hours. The IWs exist in a group of periods rather than in one period. Underwater acoustic signals also show obvious energy peaks in the periods of less than 12 min. Consistency in the periods of the two physical processes implies that acoustic waves react to the IWs through some mechanisms like mode interference and travel time fluctuation. Based on the thermistor string data, mode arriving structures are analyzed. As thermocline depth varies with time, it may cause travel time difference as much as 4-10 ms between mode 1 and 2 over 10 km range. This travel time difference causes interference among modes and thus fluctuation from range-independent stratified ocean structure. In real situations, however, there exist additional spatial variation of IWs. Model simulations with all modes and simple IWs show clear responses of acoustic signals to the IWs, i.e., fluctuations of amplitude and phase.

• ETRI Journal
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• v.10 no.2
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• pp.13-19
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• 1988

This paper describes on the interworking services. interworking issues and the design concepts in the Interworking System (IWS) between Pubilc Switched Telephone Network (PSTN) and Packet Switched Data Network (PSDN), which has been developed at the Electronics and Tedecommunications Research Institute (ETRI). As a gateway between PSTN and PSDN, IWS provides the interconnection between PSTN and PSDN. In addition to the provision of basic interconnection services (i.e. dial-in/dial-out services), IWS provides the Maintenance and Administration (M&A) services for system itself and the supplementary services such as the call barring, direct call and closed user group. The architecture of IWS is based on the multiprocessor system with single system bus. And a multiprocessor real time kernel is used to support the inter-board communication as well as the inter-process commmunications. Especially, the operation and maintenance functions of IWS are treated in detail.

• Proceedings of the KSRS Conference
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• 2007.10a
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• pp.61-64
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• 2007

Subsurface Internal Waves (IWs) can be detected in satellite images as periodic alternating brighter/darker stripes. It is known that there are two types of IWs - depression type and elevation type - depending on the water depth in stratified oceans. In this study, we have quantitatively verified the process of converting polarity from depression waves to elevation waves using ERS-2 SAR images acquired over the northern South China Sea. We simulated the evolution of IWs near a turning point with a numerical model for internal wave propagation. The simulation results near the turning point clearly showed us not only a conversion process of IWs from depression to elevation waves, but also a similar wave pattern with the observed SAR image. We also simulated SAR intensity variation near the turning point. The upper layer currents were computed at regular intervals using the numerical model, as the IWs were passing through the turning point. Then, an integrated hydrodynamic-electromagnetic model was used for simulating SAR intensity profiles from the upper layer currents at each position. The simulated SAR intensity profiles at each position were compared with the observed SAR intensities.

• Korean Journal of Remote Sensing
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• v.23 no.5
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• pp.385-391
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• 2007

Subsurface Internal Waves(IWs) can be detected in satellite images as periodic alternating brighter/darker stripes. It is known that there are two types of IWs-depression type and elevation type-depending on the water depth in stratified oceans. In this study, we have quantitatively verified the process of converting polarity from depression waves to elevation waves using ERS-2 SAR image acquired over the northern South China Sea. We simulated the evolution of IWs near a turning point with a numerical model for internal wave propagation. The simulation results near the turning point clearly showed us not only a conversion process of IWs from depression to elevation waves, but also a similar wave pattern with the observed SAR image. We also simulated SAR intensity variation near the turning point. The upper layer currents were computed at regular intervals using the numerical model, as the IWs were passing through the turning point. Then, an integrated hydrodynamic-electromagnetic model was used for simulating SAR intensity profiles from the upper layer currents. The simulated SAR intensity profiles were compared with the observed SAR intensities.

• Proceedings of the KIEE Conference
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• 1987.07b
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• pp.911-915
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• 1987

In this thesis, the architecture and design of IWS(Inter Working System) which interconnects two different networks (PSDN: Packet Switched Data Network, PSTN:Public Switched Telephone Network) are described. IWS provides interconnection services for the compatibility of communication between two networks. IWS consists of network interface protocols, protocol conversion facilities and management facilities.

• ETRI Journal
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• v.11 no.1
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• pp.136-144
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• 1989

This paper presents the interworking services and the call connection procedures in the PSTN-PSDN(Public Switched Telephone Network-Packet Switched Data Network) Interworking System(IWS). Also the architecture and design for the software and hardware in IWS are described.

• Korean Journal of Food Science and Technology
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• v.53 no.5
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• pp.521-526
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• 2021

This study characterized the chemical structure and physical properties of domestic commercial wheat starch and compared them with those of imported commercial wheat starch. Three varieties of domestic commercial wheat starch (DWS) were compared to three types of imported wheat starch (IWS). The morphology of DWS granules was spherical with diameters 17.0-18.3 ㎛; the IWS granules exhibited various diameter sizes (16.6-17.7 ㎛). The amylose content of both DWS and IWS was between 23.2-23.8%. DWS exhibited smaller gelatinization temperature ranges and gelatinization enthalpies compared to IWS. These results suggest that IWS-PW (plain wheat starch) is a mixture of many types of wheat starch. In conclusion, the quality of domestic wheat flour and imported wheat flour was related to gluten content as well as to the starch properties.

• Journal of Institute of Control, Robotics and Systems
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• v.17 no.6
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• pp.602-609
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• 2011

In this paper, we standardized the water operation system picture, process control logic, realtime database and system configuration. All aspects, including monitoring & controlling processes, symbols such as pumps, valves and pipes were standardized. As a result we have developed a specialized Integrated water operation system, iWater. We have developed a variety of advanced application programs that are essential for water treatment systems, such as IWS (Integrated Warning system), MBO(modbus opc)/LSE(LS ethernet) driver, video monitoring, self diagnosis system, network monitoring, etc. IWS prevents water supply accidents by using a variety of alarms and warning messages. Drivers have the flexibility to communicate with other 3rd party systems. We expect that iWater will eliminate any concerns regarding water-related issues while also promoting the production and fair distribution of clean water.

• Journal of Korea Society of Industrial Information Systems
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• v.3 no.1
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• pp.117-139
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• 1998

This study is intended to identify the factors affecting the successful information warehouse (IW) implementation through the technology acceptance model. As the IW has played an important role with the organizations, it has become a strategic management tool. However, because the building of an IWS requires a great amound of financing and a multi-period, managers should consider identifying the variables as a predictor of IWS success. The related research areas, such as TAM , TRA, and innovation diffusion theory, and previous research associated with the EWS success factors are reviewed in this paper. Based on the hypotheses presented , the study will empirically test the relationships between six external variable-user involvement, computer self-efficacy, OLAP characteristics, problem difficulty , user training and top management support-and system utilization via user's perceptions of ease of use, unusefulness. This study semmes to be a first attempt in this research area, and its results will provide general guidclines for IWS project managers to enhancement the like hood of system succes.

• Proceedings of the KIEE Conference
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• 1987.07b
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• pp.916-920
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• 1987

This paper describes the maintenance function and administration function in the IWS (InterWorking System between PSTN and PSDN) which Interconnects the PSTN and PSDN. The former function is for the stable operation of the IWS system, and the latter function is for the management of the subscriber, billing and statistics informations.