• Membrane and Water Treatment
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• v.6 no.2
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• pp.161-172
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• 2015

Forward osmosis (FO) is an emerging membrane technology with potential applications in desalination and wastewater reclamation. The osmotic pressure gradient across the FO membrane is used to generate water flux. In this study, flux performance and foulant deposition on the FO membrane were systematically investigated with a co-current cross-flow membrane system. Sodium alginate (SA), bovine serum albumin (BSA) and tannic acid (TA) were used as model foulants. Organics adsorbed on the membrane were peeled off via oscillation and characterized by Fourier transform infrared (FTIR) spectroscopy and scanning electron microscopy (SEM). When an initial flux of $8.42L/m^2h$ was applied, both flux reduction and foulant deposition were slight for the feed solution containing BSA and TA. In comparison, flux reduction and foulant deposition were much more severe for the feed solution containing SA, as a distinct SA cake-layer was formed on the membrane surface and played a crucial role in membrane fouling. In addition, as the initial SA concentration increased in FS, the thickness of the cake-layer increased remarkably, and the membrane fouling became more severe.

• Journal of KIISE:Information Networking
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• v.37 no.1
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• pp.57-65
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• 2010

Recently, the character recognization technique is strongly needed to enable the mobile communication devices with cameras to gather input information from the users. In general, it is not easy to reuse a CBOCR(Camera Based Optical Character Recognizer) module because of its dependency on a specific platform. In this paper, we propose a software architecture for CBOCR module providing the easy adaptability to various mobile communication platforms. The proposed architecture is composed of the platform dependency support layer, the interface layer, the engine support layer, and the engine layer. The engine layer adopts a plug-in data structure to support various hardware endian policies. We show the effectiveness of the proposed method by applying the architecture to a practical product.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.14 no.12
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• pp.4946-4960
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• 2020

In a device-to-device (D2D) underlaid cellular network, there exist two types of co-channel interference. One type is inter-layer interference caused by spectrum reuse between D2D transmitters and cellular users (CUEs). Another type is intra-layer interference caused by spectrum sharing among D2D pairs. To mitigate the inter-layer interference, we first derive the interference limited area (ILA) to protect the coverage probability of cellular users by modeling D2D users' location as a Poisson point process, where a D2D transmitter is allowed to reuse the spectrum of the CUE only if the D2D transmitter is outside the ILA of the CUE. To coordinate the intra-layer interference, the spectrum sharing criterion of D2D pairs is derived based on the (signal-to-interference ratio) SIR requirement of D2D communication. Based on this criterion, D2D pairs are allowed to share the spectrum when one D2D pair is far from another sufficiently. Furthermore, to maximize the energy efficiency of the system, a resource allocation scheme is proposed according to weighted graph coloring theory and the proposed ILA restriction. Simulation results show that our proposed scheme provides significant performance gains over the conventional scheme and the random allocation scheme.

• Journal of the Semiconductor & Display Technology
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• v.22 no.3
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• pp.142-148
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• 2023

In this paper, we identify performance issues in executing compute kernels from PolyBench, which includes compute kernels that are the core computational units of various data-intensive workloads, such as deep learning and data-intensive applications, on Processing-in-Memory (PIM) devices. Therefore, using our in-house simulator, we measured and compared the various performance metrics of workloads based on traditional out-of-order and in-order processors with Processing-in-Memory-based systems. As a result, the PIM-based system improves performance compared to other computing models due to the short-term data reuse characteristic of computational kernels from PolyBench. However, some kernels perform poorly in PIM-based systems without a multi-layer cache hierarchy due to some kernel's long-term data reuse characteristics. Hence, our evaluation and analysis results suggest that further research should consider dynamic and workload pattern adaptive approaches to overcome performance degradation from computational kernels with long-term data reuse characteristics and hidden data locality.

• Proceedings of the Korea Concrete Institute Conference
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• 1996.04a
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• pp.186-191
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• 1996

The recycled aggregate obtained from the recycled concrete may be used in road construction as crushed aggregate. The properties of recycled aggregate are reached to the values in accordance with specification for the subbase layer of the road construction. However, for the base layer of road construction, the mixtures of recycled aggregate and crushed aggregate have to be used in order to satisfy the specification. In the Batch Leaching Test the recycled aggregate has lower content of heavy matal and organic matter than those written in environmental pollution law. So it does not occur the environmental pollution.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.8 no.1
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• pp.57-63
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• 2010

Layer crystallization process was tested for the separation(or concentration) of cesium and strontium fission products in a LiCl waste salt generated from an electrolytic reduction process of a spent oxide fuel. In a crystallization process, impurities (CsCl and $SrCl_2$) are concentrated in a small fraction of the LiCl salt by the solubility difference between the melt phase and the crystal phase. Based on the phase diagram of LiCl-CsCl-$SrCl_2$ system, the separation possibility by using crystallization was determined and the molten salt temperature profile during layer crystallization operation was predicted by using mathematical calculation. In the layer crystallization process, the crystal growth rate strongly affects the crystal structure and therefore the separation efficiency. In the conditions of about 20-25 l/min cooling air flow rate and less than 0.2g/min/$cm^2$ crystal flux, the separation efficiency of both CsCl and $SrCl_2$ showed about 90% by the layer crystallization process, assuming a LiCl salt reuse rate of 90wt%.

• Proceedings of the Korean Society of Agricultural Engineers Conference
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• 2003.10a
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• pp.219-222
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• 2003

Bech scale tests were performed to evaluate the adaptability of industrial wastes, especially bottom ash, salg and phosphogypsum among others, for constructing the surface layer of a landfill or reclamation, which function is a vegetation base layer. In the test, columes test were used to check the extraction characteristics of wastes and small PVC soil-box that equipped the drainage device was used to model a performance of layers and to monitor the growth of plants at the composite layer of those. Tests have been continued during one and half year and It has been verified that bottom ash and phosphogypsum look like as a valuable material to safely reuse as the vegetation base layer even though some unconfined factors are remain.

• Membrane and Water Treatment
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• v.11 no.5
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• pp.323-331
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• 2020

With the increasing demand on reverse osmosis (RO) membranes for water purification worldwide, the number of disposed membrane elements is expected to increase accordingly. Thus, recycling and reuse of end-of-life RO membranes should be a global environmental action. In this work, we aim to reuse the spent RO membrane for nanofiltration (NF) and ultrafiltration (UF) process by subjecting the spent membrane to solvent and oxidizing solution treatment, respectively. Our results showed that solvent-treated RO membrane could perform as good as commercial NF membrane by achieving similar separation efficiencies, but with reduced water permeability due to membrane surface fouling. By degrading the polyamide layer of RO membrane, the transformed membrane could achieve high water permeability (85.6 L/㎡.h.bar) and excellent rejection against macromolecules (at least 87.4%), suggesting its reuse potential as UF membrane. More importantly, our findings showed that in-situ transformation on the spent RO membrane using solvent and oxidizing solution could be safely conducted as the properties of the entire spiral wound element did not show significant changes upon prolonged exposure of these two solutions. Our findings are important to open up new possibilities for the discarded RO membranes for reuse in NF and UF process, prolonging the lifespan of spent membranes and promoting the sustainability of the membrane process.

• Journal of the Korea Fashion and Costume Design Association
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• v.14 no.2
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• pp.215-227
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• 2012

This study aims to analyze the influences of LOHAS cuticle management, which based on LOHAS consciousness among customers using nail art shops and removes only Cuticle layer without Eponychium, on the preference and expected value of service quality. Further, it tackles how above related variables have important bearing on reuse intention. A survey was conducted only with customers over the age of 20 in Seoul, Daejeon and Daegu areas in terms of LOHAS consciousness. For the collected 389 data, frequency analysis, t-test, ANOVA, correlation analysis and multiple regression analysis were carried out by using SPSS 18.0 Version statistical package. The results are as follows. First, according to the results, it shows high positive correlation between LOHAS cuticle management based on the consciousness of LOHAS, and LOHAS cuticle management preference, tendency and willingness to transfer toward it. Second. it is proven that LOHAS consciousness tend to be possessed in older age groups, married and a professional employee layers and this LOHAS motivated groups showed high LOHAS cuticle management preference, inclination and intention of a change in management. Lastly, the reuse intention is mostly affected by experience and preference of LOHAS cuticle management. There is negative correlation between reuse intention and experience in blooding and pain during care service. Higher interest in preference of LOHAS cuticle management has highly influenced positive link with the repurchase intention.

• Membrane and Water Treatment
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• v.12 no.1
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• pp.1-9
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• 2021

This study optimized the chemical cleaning process of discarded RO membranes for reuse in less demanding separation processes. The effect of physicochemical parameters, including the temperature, cleaning time, pH of the cleaning solution, and addition of additives, on the cleaning process was investigated. The membrane performance was evaluated by testing the flux recovery rate and salt rejection before and after the cleaning process. High temperatures (45-50 ℃) resulted in a better flux recovery rate of 71% with more than 80% salt rejection. Equal time for acid and base cleaning 3-3 h presented a 72.43% flux recovery rate with salt rejection above 85%. During acid and base cleaning, the best results were achieved at pH values of 3.0 and 12.0, respectively. Moreover, 0.05% concentration of ethylenediaminetetraacetic acid presented 72.3% flux recovery, while 69.2% flux was achieved using sodium dodecyl sulfate with a concentration of 0.5%; both showed >80% salt rejection, indicating no damage to the active layer of the membrane. Conversely, 0.5% concentration of sodium percarbonate showed 83.1% flux recovery and 0.005% concentration of sodium hypochlorite presented 85.2% flux recovery, while a high concentration of these chemicals resulted in oxidation of the membrane that caused a reduction in salt rejection.