• The KIPS Transactions:PartB
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• v.12B no.5 s.101
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• pp.513-520
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• 2005

In this paper, we propose a robust multi-watermarking method based on vector quantization using an index transform function. In contrast with the conventional watermark embedding methods to embed only one watermark at a time into the original image, we present a method to embed multiple watermarks for copyright protection. The proposed method efficiently enhances the robustness by index transform function which minimizes changes of vector quantization indices against various attacks. Experimental results show that the proposed method has a good robustness against various attacks compared with the conventional multi-watermarking method based on vector quantization.

• Fisheries and Aquatic Sciences
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• v.1 no.2
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• pp.187-191
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• 1998

Chemotherapy can not be applied for the control of fish viral diseases because viruses depend on host machinery for their replication. Although new control strategies including vaccination are under development, avoidance of virus introduction by rapid and correct diagnosis is the best way of fish viral disease control. Although observation of virus particles with an electron microscope is an easy method for virus detection, it take a few days for the sample preparation. In order to shorten the sample preparation time, microwave radiation was applied in the procedure. With this method, 15 seconds was enough for fixation of virus infected fish samples or cultured cells inoculated with infectious hematopoietic necrosis virus, which takes 2-4 hours with routine methods. Also four minutes was enough for polymerization of embedding resin which takes 24-48 hours with routine methods. Samples prepared with microwave were good enough for direct electron microscopic observation and immunogold labeling assay.

• Journal of Digital Contents Society
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• v.5 no.1
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• pp.66-72
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• 2004

Beyond the digital world from the analog age, the contents are very easily copied under the illegal conditions and these are rapidly distributed by the information super highway. The increase of ilegal usage and conflict in digital content market would diminish motivation of creators for their work, furthermore break down digital content market on cyberspace. Watermarking technology support to the legal users by the protection technique based chi the digital content copyright protection method(DRM). Most of previous digital watermarking have embeded to the content. In this paper, we have researched the standardization of digital rights management and developed more efficient watermark embedding method.

• Journal of Electrical Engineering and Technology
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• v.13 no.4
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• pp.1614-1622
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• 2018

The research related to fault diagnosis in permanent magnet synchronous motors (PMSMs) has attracted considerable attention in recent years because various faults such as permanent magnet demagnetization and short-circuited turns can occur and result in unexpected failure of motor related system. Several conventional current and back electromotive force (BEMF) analysis techniques were proposed to detect certain faults in PMSMs; however, they generally deal with a single fault only. On the contrary, cases of multiple faults are common in PMSMs. We propose a fault diagnosis method for PMSMs with single and multiple combined faults. Our method uses three phase BEMF voltages based on the fast Fourier transform (FFT), support vector machine(SVM), and visualization tools for identifying fault types and severities in PMSMs. Principal component analysis (PCA) and t-distributed stochastic neighbor embedding (t-SNE) are used to visualize the high-dimensional data into two-dimensional space. Experimental results show good visualization performance and high classification accuracy to identify fault types and severities for single and multiple faults in PMSMs.

• Annual Conference on Human and Language Technology
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• 2022.10a
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• pp.521-525
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• 2022

사용자와 상호작용하는 대화시스템에서 사용자의 의도를 이해하기 위한 의도 분류는 중요한 역할을 한다. 하지만, 실제 대화시스템에서는 범위 내의 의도를 가진 발화 뿐만 아니라 범위 외의 의도를 가진 발화에 대한 인식도 중요하다. 본 논문에서는 기존에 사용되던 인코더 기반의 모델이 아닌 인코더-디코더 구조를 가지는 T5 모델을 활용하여 의도 분류 실험을 진행하였다. 또한, (K+1)-way 의도 탐지 방식이 아닌 Kway의 방식에 템퍼러처 스케일링 기법을 적용하여 범위 외 의도 발화 데이터 구축과 재학습이 필요 없는 확장성 있는 범위 외 의도 탐지 방법을 제안하였다. 범위 내 의도 분류 실험 결과 인코더-디코더 구조의 T5 모델이 인코더 구조의 모델에 비해 높은 성능을 보이며, 흔히 생성 태스크에서 활용되던 모델의 분류 태스크로의 확장 가능성을 확인하였다. 또한, 범위 외 의도 탐지 실험 결과에서는 T5 모델이 인코더 구조의 모델인 RoBERTa 보다 범위 외 탐지 재현율이 14.2%p 이상의 높은 성능을 기록하여 인코더-디코더 구조를 활용한 모델이 인코더 구조를 활용한 모델보다 범위 외 의도 탐지에 강건함을 확인하였다.

• Advances in nano research
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• v.14 no.3
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• pp.261-271
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• 2023

The present study follows three main goals. First, an analytical solution with high accuracy is developed to assess the effects of embedding pre-strained shape memory alloy (SMA) wires on the critical buckling temperatures of rectangular sandwich plates made of soft core and graphite fiber/epoxy (GF/EP) face sheets based on piecewise low-order shear deformation theory (PLSDT) using Brinson's model. As the second goal, this study compares the effects of SMAs on the thermal buckling of sandwich plates with those of carbon nanotubes (CNTs). The glass transition temperature is considered as a limiting factor. For each material, the effective ranges of operating temperature and thickness ratio are determined for real situations. The results indicate that depending on the geometric parameters and thermal conditions, one of the SMAs and CNTs may outperform the other. The third purpose is to study the thermal buckling of sandwich plates with advanced hybrid SMA/CNT/GF/EP composite face sheets. It is shown that in some circumstances, the co-incorporation of SMAs and CNTs leads to an astonishing enhancement in the critical buckling temperatures of sandwich plates.

• Journal of the Korean Geotechnical Society
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• v.39 no.12
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• pp.47-60
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• 2023

At present, in South Korea, there is a growing concern regarding solar power facilities installed on slopes because they are prone to damage caused by natural disasters, such as heavy rainfall and typhoons. Each year, these solar power facilities experience soil erosion due to heavy rainfall and foundation damage or detachment caused by strong wind loads. Despite these challenges, the interaction between the ground and structures is not adequately considered. Current analyses primarily focus on the structural stability under external loads; the overall facility site's stability-excluding the solar structures-in relation to its surrounding slopes is neglected. Therefore, in this study, we use finite-difference method analysis to simulate the behavior of the foundation and piles to assess changes in lateral displacement and bending stress in piles, as well as the safety factor of sloped terrains, in response to various influencing factors, such as pile diameter, spacing between piles, pile-embedding depth, wind loads, and dry and wet conditions. The analysis results indicate that pile spacing and wind loads significantly influence lateral displacement and bending stress in piles, whereas pile-embedding depth strongly influences the safety factor of sloped terrains. Moreover, we found that under certain conditions, the design criteria in domestic standards may not be met.

• Journal of Mechanical Science and Technology
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• v.20 no.4
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• pp.455-466
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• 2006

This study was an attempt to control and monitor Computerized Numerical Controller (CNC) machines anywhere and anytime for the development of a ubiquitous machine (u-machine). With a Personal Digital Assistant (PDA) phone, the machine status and machining data of CNC machines can be monitored in wired and wireless environments, including the environments of IMT2000 and Wireless LAN. Moreover, CNC machines can be controlled anywhere and anytime. The concept of the anywhere-anytime controlling and monitoring of a manufacturing system was implemented in this study for the purpose of u-manufacturing and u-machines. In this concept, the communication between the CNC controller and the PDA phone was successfully performed anywhere and anytime for the real-time monitoring and control of CNC machines. In addition, the interface between the CNC controller and the developed application module was implemented by Object linking and embedding for Process Control (OPC) and shared CNC memory. For communication, the design of a server contents module within the target CNC was based on a TCP/IP. Furthermore, the client contents module within the PDA phone was designed with the aid of embedded c++ programming for mobile communication. For the interface, the monitoring data, such as the machine status, the machine running state, the name of the Numerical Control (NC) program, the alarm and the position of the stage axes, were acquired in real time from real machines with the aid of the OPC method and by sharing the CNC memory. The control data, such as the start, hold, emergency stop, reserved start and reserved stop, were also applied to the CNC domain of the real machine. CNC machines can therefore be controlled and monitored in real time, anywhere and anytime. Moreover, prompt notification from CNC machines to mobile phones, including cellular phones and PDA phones, can be automatically realized in emergencies.

• Journal of Pharmacopuncture
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• v.13 no.1
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• pp.121-128
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• 2010

Objectives : This study was to investigate the effects of Oriental medical treatment on ALS. Methods : We investigated 12 ALS patients which were admitted to Gwang-Ju O.M.hospital for 3 months and follow-up at 8 months after discharge. All patients were treated by SAAM-acupuncture, herb medication, Bee venom Pharmacopuncture therapy, Needle-embedding therapy, etc and after discharge self-therapy at home. We evaluated patients using the Amyotrophic lateral sclerosis Functional Rating Scale-Revised(ALSFRS-R), Medical Research Council (MRC) Scale. Results : After 1 month, mean ALSFRS-R score of patients was $29.08{\pm}7.99$, 2 months $28.70{\pm}7.17$, 3 months $28.16{\pm}8.23$, 1 year $21.33{\pm}9.93$ and mean MRC Scale of patients was $25.34{\pm}8.45$, 2 months $25.34{\pm}8.45$, 3months $21.56{\pm}9.20$. But in both cases, the variation was not statistically significant. Conclusions : We think that the results of this case be a pilot study that proves the effect of Oriental Medical treatment on ALS.

• Journal of Korean Neurosurgical Society
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• v.29 no.11
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• pp.1429-1436
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• 2000

Objectives : This study was performed in cultured rat hippocampal neurons to investigate the acute electrophysiological features of ionotropic glutamate receptors which act as a major excitatory neurotransmitter in mammalian brain. Method : Glutamate receptor agonists were applied into the bath solution embedding in whole-cell patch-clamp recording of single hippocampal neuron. Results : In voltage-clamped at -60mV and the presence of 1mmol $Mg^{2+}$, extracellulary applied NMDA did not induce any inward current. Both the elimination of $Mg^{2+}$ and addition of glycine in bath, however, elicited a NMDAinduced inward current. $Mg^{2+}$ block current was increased gradually in more negative potentials from -30mV, showing a negative slope in I-V plot with $Mg^{2+}$. Glutamate-induced current represented an outward rectification. A non-NMDA receptor component occupied about 40% of glutamate-induced current in the voltage range of -80mV to +60mV. Conclusion : Present study suggests that glutamate activates acutely the non-NMDA receptors which induces an inward current in the level of resting membrane potential. This makes the membrane potential increase and can activate the NMDA receptors that permit calcium influx against $Mg^{2+}$ block. At the depolarized state of neuron, there may be recovery mechanisms of membrane potential to repolarize irrespective of voltage-dependent potassium channels in the hippocampal neurons.