• 한국식품영양학회지
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• 제25권4호
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• pp.1016-1022
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• 2012

In order to investigate the effects of 70% EtOH extract obtained from Hovenia dulcis Thunberg on enzymes relating reactive oxygen intermediate, cancer-stricken animals induced by DEN (N,N-diethylnitrosamine) were recovered by administering the extract of Hovenia dulcis Thunberg. It showed that there was no effect on the generation of superoxide radical by the extract of Hovenia dulcis Thunberg. However, considering the increase of the activity of Cu, Zn-SOD and Mn-SOD in the tested animal class, the extract of Hovenia dulcis Thunberg could participate directly in removing of superoxides. The experimented-animals treated with the extract of Hovenia dulcis Thunberg showed an increase in the activity of the enzymes, catalase and glutathione peroxidase, which can eliminate hydrogen peroxide pertained in liver tissue. The extract of Hovenia dulcis Thunberg seemed to have some factors that accelerate the oxidation. Also, the extract of Hovenia dulcis Thunberg showed effects on the enzymes relating to the active oxygen toxicity which could be an indicator of aging and body toxicity.

• 한국전기전자재료학회논문지
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• 제26권4호
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• pp.309-314
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• 2013

This paper dealt with the radiated electromagnetic wave detection of partial discharge (PD) in oil for insulation diagnostics of oil-immersed transformers. Three types of electrode system were fabricated to simulate the insulation defects that could occur in oil-immersed transformers. Frequency components of radiated electromagnetic wave in oil was measured by broadband bi-conical antennas of 300 MHz~2 GHz and a spectrum analyzer of 9 kHz~3 GHz. Frequency component of electromagnetic waves from PD in oil were highly distributed at 500 MHz. From the result, a narrow-band monopole antenna with the center frequency of 500 MHz was fabricated. We could detect PD signal in insulation oil without an influence of external noise by a measurement system which consists of the prototype monopole antenna, a LNA (Low Noise Amplifier), an oscilloscope and a spectrum analyzer.

• ETRI Journal
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• 제39권3호
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• pp.398-405
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• 2017

In this paper, an artificial stereo extension method that creates stereophonic sound from a mono sound source is proposed. The proposed method first trains deep neural networks (DNNs) that model the nonlinear relationship between the dominant and residual signals of the stereo channel. In the training stage, the band-wise log spectral magnitude and unwrapped phase of both the dominant and residual signals are utilized to model the nonlinearities of each sub-band through deep architecture. From that point, stereo extension is conducted by estimating the residual signal that corresponds to the input mono channel signal with the trained DNN model in a sub-band domain. The performance of the proposed method was evaluated using a log spectral distortion (LSD) measure and multiple stimuli with a hidden reference and anchor (MUSHRA) test. The results showed that the proposed method provided a lower LSD and higher MUSHRA score than conventional methods that use hidden Markov models and DNN with full-band processing.

• 한국자동차공학회논문집
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• 제20권2호
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• pp.64-69
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• 2012

Head injury is one of the most common cause of deaths in car-to-pedestrian collisions. To reduce the severity of such injuries, many international safety committees have performed headform impact test for pedestrian protection. In this paper, an adult headform impactor model is developed based on the finite element (FE) method and validated through the numerical simulation. The skin material of headform impactor is known as polyvinyl chloride skin (PVC) and its material was assumed as viscoelastic. The viscoelastic parameters of headform skin are identified by a series of trial and error methods. The new developed FE adult headform impactor is verified by the drop test and FE JARI adult headform impactor provided by Madymo program.

• Transactions on Electrical and Electronic Materials
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• 제12권4호
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• pp.152-155
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• 2011

This paper presents a comparative analysis on step and the touch voltages generated by either a sine and a ring wave voltage generator; this analysis was done as a basic study in order to develop a small and lightweight ground meter. A ring wave generator using pulsed power technology was fabricated; an experimental grounding system specified in Institute of Electrical and Electronics Engineers standards 80 and 81 was installed. The step and the touch voltages, which were measured using comparable a sine and a ring waves in terms of magnitude and frequency, were equal. Using pulsed power technology, the weight of the fabricated ring wave generator could be reduced to one-fifth of that of a sine wave generator. Consequently, if a ground meter adopts the ring wave instead of a sine wave, it will be possible to reduce the weight of a ground meter and improve the efficiency of measurement.

• 한국전기전자재료학회논문지
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• 제31권6호
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• pp.412-416
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• 2018

Most series arcs lead to electrical fires that cannot be interrupted by circuit breakers, because the arc's current is outside the breaker's operating range. In this paper, experiments were conducted on the detection and identification of series arcs to prevent electrical fires. Plugs and outlets specified in KS C 8305 were deteriorated to replicate arc faults commonly found in fields. The characteristics of series arcs resulting from various types of loose connections were determined by analyzing the frequency spectra and phase distributions of detected arc pulses. The results showed that the simulated arc defects used in this study were more similar to actual arc phenomena than the existing arc generator specified in UL 1699. In addition, loose connections, such as wire-wire, terminal-wire, and outlet-plug, can be identified by phases of $0^{\circ}$, $180^{\circ}$ and $360^{\circ}$, respectively. These phases can be detected by a band pass filter with a frequency range of 5~10 MHz, which can be used as the trip signal for circuit breakers.

• 대한임상독성학회지
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• 제16권2호
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• pp.172-175
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• 2018

Acute nicotine poisoning by liquid nicotine for electronic cigarettes is becoming an increasing problem worldwide. On the other hand, there are no regulations regarding its concentration, container or labelling in Korea. This is the first case of a cardiac arrest after liquid nicotine ingestion that was confirmed by plasma nicotine detection in Korea. A 34-year-old male was found with a cardiac arrest at home by the emergency medical services crew, and had a return of spontaneous circulation after 27 minutes of cardio-pulmonary resuscitation. The cause of his cardiac arrest was suspected to be acute nicotine poisoning by the ingestion of liquid nicotine. Toxicology analysis of the National Forensic Service confirmed plasma nicotine, and the pharmacokinetic estimated average concentration of plasma nicotine at the time of the cardiac arrest was 29.7 mg/L, a lethal dose. He was hospitalized for further treatment, but was discharged after 20 days without any improvement. Considering the strong toxicity of nicotine, appropriate policy decisions are required for sales and distribution.

• 대한임상독성학회지
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• 제16권2호
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• pp.176-180
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• 2018

Drug abuse and its related problems are increasing continuously in Korea. One of the most frequently abused drugs is methamphetamine, but there are few medical report in Korea. This is the first report of the identification of methamphetamine in the blood of a patient who had a return of spontaneous circulation after cardiac arrest and survived discharge. A 33-year-old male arrived at the emergency department presenting with chest pain and dyspnea. He had ingested methamphetamine and alcohol approximately 7 hours before arrival. One hour after arrival, he had seizure followed by cardiac arrest. Spontaneous circulation was recovered after 4 minutes of CPR. An analysis of the National Forensic Service identified plasma methamphetamine with an estimated average concentration of plasma methamphetamine at the time of arrival of 0.6 mg/L, a lethal dose. He had rhabdomyolysis and acute kidney injury but survived after continuous renal replacement therapy. Since then, he has suffered chronic kidney disease, and he is being followed up at the out-patient department. In Korea, although drug abuse is still uncommon, it is on the increase. Therefore, emergency physicians should be aware of the clinical characteristics of methamphetamine poisoning.

• 정보보호학회논문지
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• 제33권2호
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• pp.295-303
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• 2023

클라우드 컴퓨팅 시장이 성장하면서 다양한 클라우드 서비스가 안정적으로 제공되고 있으며 국내행정·공공기관은 모든 정보시스템을 클라우드 시스템으로 운영하기 위한 전환사업을 수행하고 있다. 그러나 인터넷을 통해 클라우드 자원에 접근할 경우, 내·외부 인력의 잘못된 자원 사용 및 악의적인 접근이 가능하기 때문에 사전에 클라우드 서비스를 안전하게 운영하기 위한 보안 기술을 마련하는 것이 필요하다. 본 논문은 클라우드 서비스 중, 민감한 데이터를 저장하는 클라우드 스토리지 서비스에 대해 제로 트러스트 기반으로 보안 기술을 설계하고, 설계된 보안기술을 실제 클라우드 스토리지에 적용하여 보안 기술의 실효성을 검증한다. 특히, 보안 기술 적용 여부에 따른 클라우드 사용자의 상세 접근 및 사용 행위를 추적하기 위하여 메모리 포렌식, 웹 포렌식, 네트워크 포렌식을 수행한다. 본 논문에서는 클라우드 스토리지 서비스로서 Amazon S3(Simple Storage Service)를 사용하고, S3의제로트러스트 기술로는 접근제어목록 및 키 관리 기술을 사용한다. 또한, S3에 대한 다양한 접근 유형을 고려하기 위하여 AWS(Amazon Web Services) 클라우드 내·외부에서 서비스 요청을 발생시키고, 서비스 요청위치에 따른 보안 기술 적용 효과를 분석한다.

• 생약학회지
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• 제43권2호
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• pp.137-146
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• 2012

Dipsaci Radix (Dipsacaceae) has been used as a tonic, an analgesic, anti-inflammatory and anti-complement agents in traditional herbal medicine for the therapy of low back pain, knee pain, rheumatic arthritis, traumatic hematoma, and bone fractures. A high-performance liquid chromatography-electrospray ionization-mass spectrometric method (HPLC-ESI-MS) was developed for the simultaneous quantitation method of the five compounds from the herbal drug: asperosaponin VI and asperosaponin XII (terpene glycosides), sweroside, loganin and dipsacus A(iridoid glycosides). HPLC separation of the analytes was achieved on a C18 column ($150{\times}2.0$ mm i.d., 5 ${\mu}m$) using the aqueous methanol containing 5 mM ammonium acetate with gradient flow of the mobile phase. Detection of the analytes was performed by positive ion electrospray ionization, and selected ion monitoring was used for data acquisition using m/z corresponding molecular adduct ion, $[M+NH_4]^+$ and $[M+H]^+$. Calibration graphs showed good linearity ($r^2$=0.9997) over the wide range of the analytes; intra- and inter-day precisions (RSD, %) were within 9.1% and the accuracy between 94.0-111.0%. Recoveries of the analytes through the assay procedure were in the range of 93.7-110.8%. Analytical results of the herbal drugs of Dipsaci Radix (17 samples) show wide distribution of the five marker compounds and clear difference of the species from Phlomidis Radix (4 samples). The developed method would provide a practical guide for the quality control of the herbal drug.