• Title/Summary/Keyword: variability management

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Spatial and Temporal Variations of Water Quality in an Urban Miho Stream and Some Influences of the Tributaries on the Water Quality (청주지역의 도심하천인 미호천에서 시공간적 수질변이 특성 및 유입지천의 영향)

  • Kim, Ji-Il;Choi, Ji-Woong;An, Kwang-Guk
    • Journal of Environmental Science International
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    • v.23 no.3
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    • pp.433-445
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    • 2014
  • The objective of study was to analyze seasonal and inter-annual patterns of water chemistry of Miho Stream watershed during 2004 - 2007 along with some influences of tributaries and summer monsoon on the stream water quality. For the study, eight physico-chemical parameters such as nitrogen, phosphorus, BOD, COD and chlorophyll-a (CHL) etc. were analyzed in relation to spatial and temporal variability of seven sampling sites of the mainstream and some tributaries in the watershed. In the upstream reach, Mean of BOD, COD and TP averaged 3.2 mg/L, 6.5 mg/L and $186{\mu}g/L$, respectively, indicating an eutrophic conditions as a III-rank in the stream water quality criteria from the Ministry of Environment, Korea(MEK). The eutrophic water was due to a combined effect of Chiljang tributary with high nutrients ($TP=844{\mu}g/L$, TN=8.087 mg/L) and the point sources from some wastewater treatment plants. In the meantime, BOD, TN, and TP in the downstream reach were about > 1.2-1.5 folds than the values of the midstream reaches. This was mainly attributed to effluents of nutrient rich-water (mean TN: 11.980 mg/L) from two tributaries of Musim Stream and Suknam Stream, which is directly influenced by nearby wastewater disposal plants. Seasonal analysis of water chemistry showed that summer monsoon rainfall was one of the important factors influencing the water quality, and water quality had a large spatial heterogeneity during the rainfall period. In the premonsoon, BOD in the downstream averaged $6.0{\pm}2.47mg/L$, which was 1.4-fold greater than the mean of upstream reach. Mean of CHL-a as an indicator of primary productivity in the water body, was > 2.2 - 2.9 fold in the downstream than in the upstream, and this was a result of the high phosphorus loading from the watershed. Overall, our data suggest that some nutrient controls in point-source tributary streams are required for efficient water quality management of Miho Stream.

Assessment of Climate Change Impacts on Water Resources in the Gyeongan-cheon Watershed Using Multiple GCMs (다중 GCM 미래 기후자료를 이용한 경안천 유역의 수자원에 대한 기후변화 영향 평가)

  • Kim, Chul-Gyum;Cho, Jaepil;Kim, Hyeonjun
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.40 no.1
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    • pp.119-126
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    • 2020
  • This study analyzed the effects of future climate change on water resources in the Gyeongan-cheon watershed of the Han River. Considering the uncertainties of GCM climate data, future data using 16 GCMs and SQM downscaling method are used. And SWAT model was applied to simulate the hydrological changes from the past to the future. The maximum to minimum difference according to GCM for the future period (2010-2099) was about 1,500 mm of annual precipitation, 150 mm of evapotranspiration, 1,380 mm of runoff, and the deviation from the mean was -40 % to +60 % of precipitation, ±15 % of evapotranspiration, -60 % to +90 % of runoff, which means that the variability is very high according to GCM. The impacts of climate change over the three future periods showed that precipitation, evapotranspiration, and runoff were expected to increase gradually toward the far future (2070-2099), and would be relatively larger under the RCP 8.5 scenario. On a monthly basis, it was analyzed that precipitation and runoff increased in July to September, while the evapotranspiration decreased in July and August, and increased in September and October. The results of this study are expected to be helpful in understanding the future climate impacts of various GCM data and the uncertainties associated with GCMs.

Comparison of the Clinical Characteristics of Patients with Burning Mouth Syndrome due to Hyposalivation (타액분비저하에 따른 구강작열감증후군 환자의 임상적 특징 비교)

  • Lee, Ha-nul;Kim, Dong-yoon;Baek, So-young;Jeong, Hae In;Lee, Hyun-Jin;Cho, Yunjae;Ha, Na-yeon;Kim, Jinsung
    • The Journal of Internal Korean Medicine
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    • v.41 no.5
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    • pp.838-847
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    • 2020
  • Objectives: The aim of this study was to investigate the clinical characteristics of patients with Burning Mouth Syndrome (BMS) due to hyposalivation (HS). Methods: We reviewed the clinical records of 39 BMS patients who visited the Department of Digestive Diseases of Kyunghee Korean Medicine Hospital from March 1st, 2020 to July 31st, 2020. The subjects were classified according to the presence or absence of hyposalivation and both groups were compared for the proportion of coated tongue, heart rate variability (HRV), Ryodoraku, and the numeral rating scale (NRS) score of tongue pain results. Results: The BMS with Hyposalivation (HS group) and the BMS without Hyposalivation (Non-HS group) showed a significant difference in the proportion of coated tongue and the NRS score for tongue pain. The NRS score was significantly higher in the Non-HS group and the proportion of coated tongue was lower. However, no significant differences were noted in several HRV parameters between the two groups. The most frequent accompanying symptoms were xerostomia and dyspepsia. Conclusions: The results of this study suggest that hyposalivation might be one of the main causes of tongue pain, the key complaint in BMS patients. Sympathetic/parasympathetic imbalance might not be a main contribution of hyposalivation in BMS. Instead, factors such as the number of medications taken seem to correlate with hyposalivation in BMS. This results could be useful in the management of BMS patients with hyposalivation in clinical practice.

Development of Biomass Evaluation Model of Winter Crop Using RGB Imagery Based on Unmanned Aerial Vehicle (무인기 기반 RGB 영상을 이용한 동계작물 바이오매스 평가 모델 개발)

  • Na, Sang-il;Park, Chan-won;So, Kyu-ho;Ahn, Ho-yong;Lee, Kyung-do
    • Korean Journal of Remote Sensing
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    • v.34 no.5
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    • pp.709-720
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    • 2018
  • In order to optimize the evaluation of biomass in crop monitoring, accurate and timely data of the crop-field are required. Evaluating above-ground biomass helps to monitor crop vitality and to predict yield. Unmanned Aerial Vehicle (UAV) imagery are being assessed for analyzing within field spatial variability for agricultural precision management, because UAV imagery may be acquired quickly during critical periods of rapid crop growth. This study reports on the development of remote sensing techniques for evaluating the biomass of winter crop. Specific objective was to develop statistical models for estimating the dry weight of barley and wheat using a Excess Green index ($E{\times}G$) based Vegetation Fraction (VF) and a Crop Surface Model (CSM) based Plant Height (PH) value. As a result, the multiple linear regression equations consisting of three independent variables (VF, PH, and $VF{\times}PH$) and above-ground dry weight provided good fits with coefficients of determination ($R^2$) ranging from 0.86 to 0.99 with 5 cultivars. In the case of the barley, the coefficient of determination was 0.91 and the root mean squared error of measurement was $102.09g/m^2$. And for the wheat, the coefficient of determination was 0.90 and the root mean squared error of measurement was $110.87g/m^2$. Therefore, it will be possible to evaluate the biomass of winter crop through the UAV image for the crop growth monitoring.

Non-stationary Frequency Analysis with Climate Variability using Conditional Generalized Extreme Value Distribution (기후변동을 고려한 조건부 GEV 분포를 이용한 비정상성 빈도분석)

  • Kim, Byung-Sik;Lee, Jung-Ki;Kim, Hung-Soo;Lee, Jin-Won
    • Journal of Wetlands Research
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    • v.13 no.3
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    • pp.499-514
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    • 2011
  • An underlying assumption of traditional hydrologic frequency analysis is that climate, and hence the frequency of hydrologic events, is stationary, or unchanging over time. Under stationary conditions, the distribution of the variable of interest is invariant to temporal translation. Water resources infrastructure planning and design, such as dams, levees, canals, bridges, and culverts, relies on an understanding of past conditions and projection of future conditions. But, Water managers have always known our world is inherently non-stationary, and they routinely deal with this in management and planning. The aim of this paper is to give a brief introduction to non-stationary extreme value analysis methods. In this paper, a non-stationary hydrologic frequency analysis approach is introduced in order to determine probability rainfall consider changing climate. The non-stationary statistical approach is based on the conditional Generalized Extreme Value(GEV) distribution and Maximum Likelihood parameter estimation. This method are applied to the annual maximum 24 hours-rainfall. The results show that the non-stationary GEV approach is suitable for determining probability rainfall for changing climate, sucha sa trend, Moreover, Non-stationary frequency analyzed using SOI(Southern Oscillation Index) of ENSO(El Nino Southern Oscillation).

Seasonal Relationship between El Nino-Southern Oscillation and Hydrologic Variables in Korea (ENSO와 한국의 수문변량들간의 계절적 관계 분석)

  • Chu, Hyun-Jae;Kim, Tae-Woong;Lee, Jong-Kyu;Lee, Jae-Hong
    • Journal of Korea Water Resources Association
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    • v.40 no.4
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    • pp.299-311
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    • 2007
  • Climatic abnormal phenomena involving El Nino and La Nina have been frequently reported in recent decades. The interannual climate variability represented by El Nino-Southern Oscillation (ENSO) is sometimes investigated to account for the climatic abnormal phenomena around the world. Although many hydroclimatologists have studied the impact of ENSO on regional precipitation and streamflow, however, there are still many difficulties in finding the dominant causal relationship between them. This relationship is very useful in making hydrological forecasting models for water resources management. In this study, the seasonal relationships between ENSO and hydrologic variables were investigated in Korea. As an ENSO indicator, Southern Oscillation Index (SOI) was used. Monthly precipitation, monthly mean temperature, and monthly dam inflow data were used after being transformed to the standardized normal index. Seasonal relationships between ENSO and hydrologic variables were investigated based on the exceedance probability and distribution of hydrologic variables conditioned on the ENSO episode. The results from the analysis of this study showed that the warm ENSO episode affects increases in precipitation and temperature, and the cold ENSO episode is related with decreases in precipitation and temperature in Korea. However, in some regions, the local relationships do not correspond with the general seasonal relationship.

Evaluation of Peri-procedural Anticoagulation Drug Therapy undergoing Radiofrequency Ablation in Patients with Atrial Fibrillation (심방세동 환자의 고주파 도자절제술 전.후의 항응고약물요법 사용실태 분석)

  • Kim, Su-Hyun;An, Sung-Shim;Kim, Soon-Joo;Bang, Joon-Seok;La, Hyen-Oh
    • Korean Journal of Clinical Pharmacy
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    • v.20 no.2
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    • pp.159-164
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    • 2010
  • Radiofrequency ablation (RA) is being used to manage atrial fibrillation (AF) with patients failed at the $1^{st}$-line anti-arrhythmic medications. Patients undergoing this procedure are at increased risk of thromboembolism after ablation, and anticoagulation management surrounding the ablation remains controversial. Although no conclusive recommendations can be made, published guidelines and data support therapeutic anticoagulation with warfarin. The purpose of this study was to analyze effectiveness of current therapy and to find factors fluctuate International Normalized Ratio (INR) values in patients undergone RA followed by anticoagulation service (ACS). Retrospective review was conducted utilizing database in a hospital. Among 110 patients under warfarin around ablation between January 2006 to September 2007, 54 patients were selected and allocated into 2 groups: Group A included 47 who discontinued warfarin after ablation, while 7 in B continued the medication. Information on demographics, amount and length of warfarin dosing, INR values and measuring frequencies, and the causing factors on INR fluctuation were abstracted. Differences were analyzed using chi-squared test, Fisher's Exact test, and unpaired Student t-test. Mean amount of warfarin before and after surgery was 4.0 mg, 4.1 mg in Group A and was 5.1 mg, 4.6 mg in Group B, respectively. Average duration of warfarin doing before ablation was 73.7 days in Group A, 129.9 days in B with no significant difference (p = 0.312). The duration time of warfarin on groups after ablation lasted several months. The number of checking INRs was 4.1 and 7.6, respectively. Inter-individual variability of INR fluctuations were $2.1{\pm}0.6$ in Group A and $2.2{\pm}0.7$ in B which were not significantly different (p = 0.062). 164 cases of decreased INR were: 'omission in taking medication, stressfulness and headache, 'increased intake of high vitamin K foods', 'lifestyle change of increased physical activities', and 'increase of food-intakes'. To the contrary, 36 cases of increased INR were: 'reduce of food-intake', 'use of non-prescription drugs', 'reduction in physical activities', and 'excessive restriction on food-intake', consecutively. In conclusion, the study validated therapeutic outcomes of RA patients who we treated with standard guideline and demonstrated 9 factors of INR fluctuations in the patient. A well-trained, pharmacist-monitored anticoagulation service could reduce the risk of adverse effects and prevent complications in patients with AF around RA operation.

A Feature-Oriented Method for Extracting a Product Line Asset from a Family of Legacy Applications (레거시 어플리케이션 제품군으로부터 제품라인 자산을 추출하는 휘처 기반의 방법)

  • Lee, Hyesun;Lee, Kang Bok
    • KIPS Transactions on Software and Data Engineering
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    • v.6 no.7
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    • pp.337-352
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    • 2017
  • Clone-and-own reuse is an approach to creating new software variants by copying and modifying existing software products. A family of legacy software products developed by clone-and-own reuse often requires high maintenance cost and tends to be error-prone due to patch-ups without refactoring and structural degradation. To overcome these problems, many organizations that have used clone-and-own reuse now want to migrate their legacy products to software product line (SPL) for more systematic reuse and management of software asset. However, with most of existing methods, variation points are embedded directly into design and code rather than modeled and managed separately; variation points are not created ("engineered") systematically based on a variability model. This approach causes the following problems: it is difficult to understand the relationships between variation points, thus it is hard to maintain such code and the asset tends to become error-prone as it evolves. Also, when SPL evolves, design/code assets tend to be modified directly in an ad-hoc manner rather than engineered systematically with appropriate refactoring. To address these problems, we propose a feature-oriented method for extracting a SPL asset from a family of legacy applications. With the approach, we identify and model variation points and their relationships in a feature model separate from implementation, and then extract and manage a SPL asset from legacy applications based on the feature model. We have applied the method to a family of legacy Notepad++ products and demonstrated the feasibility of the method.

An Approach to Managing Requirements as a Core Asset in Software Product-Line (소프트웨어 프로덕트 라인에서 핵심 자산으로서 요구사항을 관리하는 방법)

  • 문미경;염근혁
    • Journal of KIISE:Software and Applications
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    • v.31 no.8
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    • pp.1010-1026
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    • 2004
  • The goal of product line engineering is to support the systematic development of a set of similar software systems by understanding and controlling their common and distinguishing characteristics. The product line engineering is a process that develops reusable core assets and develops a set of software-intensive systems from a common set of core assets in a prescribed way. Currently, many software development technologies are accomplished in context of product line. However, much of the product line engineering research have focused on the reuse of work products relating to the software's architecture, detail design, and code. The product lines fulfill the promise of tailor-made systems built specifically for the needs of particular customers or customer groups. In particular, commonality and variability play central roles in the all product line development processes. These must be treated already during the requirement analysis phase. Requirements in product line engineering are basis of software development just like as traditional system development engineering, and basis of deciding other core assets' property - commonalities and variabilities. However, it is difficult to elicit, analyze and manage correct requirements. Therefore, it is necessary to develop systematic methods which can develop and manage requirement as core asset, which can be stable in anticipative change and can be well adapted to unpredictable change. In this paper, we suggest a method of managing requirements as core asset in product line. Through this method, the reuse of domain requirements can be enhanced. As a result, the cost and time of software development can be reduced and the productivity can be increased.

Analysis of Association with Risk Factors of Cardiovascular Disease and Heart Rate Variability (심박동수 변이에 따른 심혈관질환 위험 인자와의 관련성에 미치는 영향 분석)

  • Lim, Bo-Hee;Seok, Jong-Min;Jeon, Woo-Jin;Ko, Eun-Ju;Lee, Jin
    • Journal of the Korean Society of Radiology
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    • v.12 no.3
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    • pp.321-328
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    • 2018
  • The purpose of this study was to investigate factors affecting the heart rate, to analyze the relevance and to use it as a management index of factors of increase in heart rate. A total of 204 adults from November, 2016 to March, 2017 who responded to a personal questionnaire among the adults who underwent coronary computed tomography scans for health screening, were the target of the investigation. In the study, there was a statistically significant difference (p <.05) between the heart rate and the gender, CACS, Stenosis and the forces affecting cardiovascular disease. CACS, Stenosis had a statistically significant difference (p <.05) compared with the other groups in the group with a heart rate of 80 bpm or more, the ability to influence cardiovascular disease was different from that of other groups There was a meaning difference in the heart rate below 60 bpm group compared (p <.05). In conclusion, it is important and desirable to maintain heart rate below 60 bpm in order to prevent having cardiovascular disease history, and below 80 bpm to prevent CACS and stenosis.