• 대한지리학회지
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• 제39권4호
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• pp.544-561
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• 2004

본 연구에서는 대관령 지역의 산림 및 농경지 소유역을 대상으로 주 1회의 유량 및 수질 조사를 실시하고 유량 및 수질 항목간의 상관관계를 분석하였다. 산림 소유역의 수질 변화는 적었던 반면 농경지 소유역에서는 화학비료 및 가축분 퇴비의 시용과 토양 유실로 인해 큰 폭의 수질 변화를 보였다. 용존산소량(DO)은 두 소유역에서 유량보다는 수온과 매우 뚜렷한 음의 상관관계를 나타냈다. 산림 소유역에서는 농경지 소유역에 비해 유량과 총질소(T-N) 및 $K^{+}$의 양의 상관관계가 뚜렷하게 나타났다. 반면, 농경지 소유역에서는 부유물질 총량(TSS), 총인(T-P) 및 화학적 산소요구량(COD)이 유량과 높은 상관성을 보였다. 대관령 지역에서는 도암호의 수질 오염, 특히 T-P의 증가가 심각하다는 점에 비추어 볼 때 수질 개선을 위해서는 농경지의 토양 유실 방지가 매우 중요하다. 특히 고랭지 채소 파종기에 해당하는 6월말에서 7월초에 이르는 기간의 토양 및 양분유실이 가장 심각한 것으로 나타나 이를 줄이기 위한 친환경농법 도입이 요구된다.

• Tuberculosis and Respiratory Diseases
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• 제81권4호
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• pp.261-273
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• 2018

Chronic obstructive pulmonary disease (COPD) results in high morbidity and mortality among patients nationally and globally. The Korean clinical practice guideline for COPD was revised in 2018. The guideline was drafted by the members of the Korean Academy of Tuberculosis and Respiratory Diseases as well as the participating members of the Health Insurance Review and Assessment Service, Korean Physicians' Association, and Korea Respiration Trouble Association. The revised guideline encompasses a wide range of topics, including the epidemiology, diagnosis, assessment, monitoring, management, exacerbation, and comorbidities of COPD in Korea. We performed systematic reviews assisted by an expert in meta-analysis to draft a guideline on COPD management. We expect this guideline to facilitate the treatment of patients with respiratory conditions by physicians as well other health care professionals and government personnel in South Korea.

• 대한후두음성언어의학회지
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• 제18권2호
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• pp.108-112
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• 2007

Otolaryngological manifestations of acid reflux include a wide range of pharyngeal and laryngeal symptoms ; and the constellation of symptoms has been called laryngopharyngeal reflux (LPR). In the absence of definite diagnostic criteria, LPR disease remains a subjective entity. A diagnosis of LPR is usually based on response of symptoms to empirical treatment. Investigative modalities such as pH monitoring and, more recently, impedance studies are generally reserved for treatment failures. LPR usually requires more aggressive and prolonged treatment to achieve regression of both symptoms and laryngeal findings. The suppression of gastric acid and secretion with anti-secretary agents has been the mainstay of medical treatment for patients with acid-related disorders. The suppression of gastric acid secretion achieved with Hz-receptor antagonist $(H_2RA)$ has proved suboptimal for relief of reflux symptoms. The rapid development of tolerance and rebound acid hypersecretion after the with-drawal of $H_2RA$ limit their clinical use. Proton pump inhibitors (PPI) have been proved to be very effective for suppressing intragastric acidity, but the optimal dose and duration is unknown. Current evidence indicates that pharmacologic intervention should include, at a minimum, a 3 month trial of twice daily PPI. Symptoms of LPR improve over 2 months of therapy. The physical findings of LPR resolve more slowly than the symptoms and this continues through out at least 6 months of treatment. For most patients with LPR, twice daily dosing with a PPI is usually recommended for an initial treatment for a period of no less than 6 months treatment, and lifetime treatment may be required.

• Smart Structures and Systems
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• 제22권2호
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• pp.133-137
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• 2018

Increasing interest in prognostics and health management has heightened the need for wireless sensor networks (WSN) with efficient power sources. Piezoelectric energy harvesters using Pb(Zr,Ti)O3 (PZT) are one of the candidate power sources for WSNs as they efficiently convert mechanical vibration energy into electrical energy. These types of devices are resonated at a specific frequency, which has a significant impact on the amount of energy harvested, by external vibration. Hence, precise prediction of mechanical deformation including modal analysis of piezoelectric devices is crucial for estimating the energy generated under specific conditions. In this study, an experimental vibrational system capable of controlling a wide range of frequencies and accelerations was designed to generate mechanical vibration for piezoelectric energy harvesters. In conjunction with MATLAB, the system automatically finds the resonance frequency of harvesters. A small accelerometer and non-contact laser displacement sensor are employed to investigate the mechanical deformation of harvesters. Mechanical deformation under various frequencies and accelerations were investigated and analyzed based on data from two types of sensors. The results verify that the proposed system can be employed to carry out vibration experiments for piezoelectric harvesters and measurement of their mechanical deformation.

• 한국인터넷방송통신학회논문지
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• 제14권3호
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• pp.1-6
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• 2014

최근 네트워크회선 사용비용의 안정화로 인해 IP방송과 통신장비가 확대 보급되고 있으나, TV, DID와 같은 멀티미디어에는 고가의 네트워크 시스템을 이용한 통합관리 시스템을 사용하고 있지 않다. 제안된 멀티미디어 통합 TCU(terminal control unit)는 Wake-on-Lan을 셋탑박스에 탑재한 후에 기존 네트워크의 IP통신망을 사용하여 TV전원의 On/Off의 상태 확인 및 원격제어, 전원 제어 예약 기능(관제실 소프트웨어 지원), TV채널 변경, 다양한 인터페이스 입출력 AC전원 & Lan포트, RS-232C, IR등을 지원하는 제어기기로 기존에 저가의 제어기기로 사용되던 RF방식과는 다르게 24시간 감시 및 제어할 수 있다. 높은 가격과 확장성이 전무한 기존 제어장비에서 24시간 모니터링 기능과 자동제어 시스템 지원과 저가격인 TCU(Termial Control Unit)의 개발은 폭넓은 사용처를 확보할 것으로 예상된다.

• Journal of Electrochemical Science and Technology
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• 제9권3호
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• pp.229-237
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• 2018

The electrochemical sensing performance of metal-graphene hybrid based sensor may be significantly decreased due to the dissolution and aggregation of metal catalyst during operation. For the first time, we developed a novel large-area high quality three dimensional graphene foam-incorporated gold nanoparticles (3D-GF@Au) via chemical vapor deposition method and employed as free-standing electrocatalysis for non-enzymatic electrochemical glucose detection. 3D-GF@Au based sensor is capable to detect glucose with a wide linear detection range of $2.5{\mu}M$ to 11.6 mM, remarkable low detection limit of $1{\mu}M$, high selectivity, and good stability. This was resulted from enhanced electrochemical active sites and charge transfer possibility due to the stable and uniform distribution of Au NPs along with the enhanced interactions between Au and GF. The obtained results indicated that 3D-GF@Au hybrid can be expected as a high quality candidate for non-enzymatic glucose sensor application.

• Natural Product Sciences
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• 제17권2호
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• pp.147-159
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• 2011

A high-performance liquid chromatography-electrospray ionization-tandem mass spectrometric method was developed to determine simultaneously eight marker constituents of Forsythiae fructus, and subsequently applied it to classify its two botanical origins. The marker compounds of Forsythia suspensa were phillyrin, pinoresinol, phillygenin, lariciresinol and forsythiaside; those of F.viridissima were arctiin, arctigenin and matairesinol. Separation of the eight analytes was achieved on a phenyl-hexyl column (150${\times}$2.0 mm i.d., 3 ${\mu}M$) using gradient elution with the mobile phase: (A) 10% acetonitrile in 0.5% acetic acid, (B) 40% aqueous acetonitrile. A few fragment ions specific to the types of lignans, among the product ions generated by collisonally induced dissociation (CID) of molecular ion clusters, such as [M-H]$^-$ or [M+OAc]$^-$ were used not only for fingerprinting analysis but for the quantification of each epimer by using multiple-reaction monitoring mode. It was shown good linearity ($r^2{\geq}$ 0.9998) over the wide range of all analytes; intra- and inter-day precisions (RSD, %) were within 9.14% and the accuracy ranged from 84.3 to 115.1%. The analytical results of 40 drug samples, combined with multivariate statistical analyses - principal component analysis (PCA) and hierarchical cluster analysis (HCA) - clearly demonstrated the classification of the test samples according to their botanical origins. This method would provide a practical strategy for assessing the authenticity or quality of the herbal drug.

• 응용통계연구
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• 제30권5호
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• pp.647-663
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• 2017

와이블 분포는 제품의 물리적 특성을 잘 반영하고 고장률이 증가하거나 감소하는 경우 모두를 나타낼 수 있기 때문에 재품의 수명을 모델링할 때 가장 많이 사용되는 분포이다. 일반적으로 수명시험에서 표본의 모든 제품의 수명이 측정될 때까지 시험을 진행하는 것이 원칙이지만 여러 가지 시간적 또는 비용적인 제약으로 인해 시험을 중도절단 하는 경우가 빈번하게 발생한다. 이 논문에서는 제품의 수명 데이터가 와이블 분포를 따르고 제1형 우측중도절단된 경우 척도모수의 변화를 탐지하는 Weibull generalized likelihood ratio (GLR) 관리도 절차를 제안하였다. 모의실험을 실시하여 제안한 GLR 관리도와 기존에 제안된 두 가지 CUSUM 관리도의 성능을 average run length (ARL)을 이용하여 비교하였다. 그 결과 이 논문에서 제안한 GLR 관리도는 형상모수와 표본의 크기가 크고 중도절단율이 아주 높지 않은 경우 척도모수의 다양한 변화를 탐지하는데 효율적임을 알 수 있었다.

• Bulletin of the Korean Chemical Society
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• 제35권2호
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• pp.371-376
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• 2014

A novel three-phase hollow fiber liquid phase microextraction was developed for the determination of malachite green (MG) in environmental waters, which selected [BMIM][$PF_6$] mixed with 1% trioctylphosphine oxide (TOPO) as supported phase. Several parameters (accepter phase pH, sample pH, supported phase membrane, volume of accepter phase, salinity, extraction time) that could affect extraction performance were investigated. Under the optimal extraction conditions, the established approach showed excellent characters as: high enrichment factor (212), wide linear range ($0.20-100{\mu}gL^{-1}$), low detection limit ($0.01{\mu}gL^{-1}$), good reproducibility (RSD, 8.9%, n=5) and satisfactory recovery (84.0-106.2%). The method was applied to detect MG at Yangtze River and pond waters in Zhenjiang, Jiangsu province, and 4 sites among 15 sampling sites were found MG with the concentration of $1.73-11.06{\mu}gL^{-1}$, which confirmed that the proposed environmentally friendly method was simple and effective for monitoring MG in aquatic system.

• 한국태양에너지학회 논문집
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• 제28권6호
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• pp.78-86
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• 2008

The aim of this paper is to show the daylight environment of a light pipe system according to sun movement. A light pipe system has been mounted on the roof of the windowless full scale model: the solar spot has diameter of 0.65m and is 1.3m long, giving an aspect ratio of 1:2. The full scale model was installed on the rooftop of the SHINAN apartment in Yongin city that has no obstructions against sunlight. The test room is equipped with sensors for the measurements of the internal illuminance and has an area of 6m(W)$\times$6m(D)$\times$4m(H). The system has been monitored with a data-logger to evaluate the cumulative distribution of illuminance on a floor-plane from 16th, April to 29th, May, 2008 over one month and selected clear sky condition. For the daylight performance of floor area, the totally 49 measuring points has been used to determine the internal illuminance and an HP datalogger(HP34970A) records the measurements for one consecutive month. The horizontal external illuminance has been measured with two outdoor sensors. This paper presents the results of monitoring light pipe system with internal/external illuminance ratio and cumulative frequency distribution of floor-plane illuminance are discussed The results show that lightpipe is proficient device for introducing daylight into the building. However It provided different daylight indoor environment with wide or narrow Interquatile range of illuminance, internal/external illuminance ratio and cumulative frequency distribution according to solar positions under suuny sky condition. For more achieving the improvement of lightpipes also include energy savings, user visual comfort with various indicators; seasonal solar height, room and lightpipes geometries.