• KDI Journal of Economic Policy
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• 제41권4호
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• pp.67-99
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• 2019

This paper, focusing on the renewable portfolio standard (RPS), evaluates alternative renewable energy policies. We propose a tractable equilibrium model which provides a structural representation of Korea's electricity market, including its energy settlement system and renewable energy certificate (REC) transactions. Arbitrage conditions are used to define the core value of REC prices to identify relevant competitive equilibrium conditions. The model considers R&D investments and learning effects that may affect the development of renewable energy technologies. The model is parameterized to represent the baseline scenario under the currently scheduled RPS reinforcement for a 20% share of renewable generation, and then simulated for alternative scenarios. The result shows that the reinforcement of the RPS leads to higher welfare compared to weakening it as well as repealing it, though there remains room to enhance welfare. It turns out that subsidies are welfare-inferior to the RPS due to financial burdens and that reducing nuclear power generation from the baseline yields lower welfare by worsening environmental externalities.

• 가정과삶의질연구
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• 제22권5호
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• pp.303-318
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• 2004

This study was conducted to develop and propose a model for an organizational system and management strategies for Healthy Families Centers. As baseline research, the organization of comparable institutions such as the Social Welfare Center, Women's Development Center, Elderly Welfare Center, Child Welfare Center, and Childcare Information Center was analyzed. Based on the results of baseline research and the draft version of Healthy Families Act, this study proposed a management model for Healthy Families Centers. This proposed model suggests the city, county, and district level centers to be organized with three divisions: 1. family counseling team, 2. family education team, and 3. family life team. Concrete assignments for the teams are also proposed. Finally, a networking system for more effective management of the healthy families centers was also proposed.

• 전기전자학회논문지
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• 제24권4호
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• pp.1011-1016
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• 2020

We propose a framework called Stacked Gated Recurrent Unit - Infrequent Residual Analysis (SG-IRA) that detects anomalies in time-series data that can be trained on streams of raw sensor data without any pre-labeled dataset. To enable such unsupervised learning, SG-IRA includes an estimation model that uses a stacked Gated Recurrent Unit (GRU) structure and an analysis method that detects anomalies based on the difference between the estimated value and the actual measurement (residual). SG-IRA's residual analysis method dynamically adapts the detection threshold from the population using frequency analysis, unlike the baseline model that relies on a constant threshold. In this paper, SG-IRA is evaluated using the industrial control systems (ICS) datasets. SG-IRA improves the detection performance (F1 score) by 5.9% compared to the baseline model.

• 한국농공학회논문집
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• 제53권6호
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• pp.75-84
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• 2011

The objective of this study is to evaluate the hydrologic impacts of climate and land use changes in a rural small watershed. HadCM3 (Hadley Centre Coupled Model, ver.3) A2 scenario and LARS-WG (Long Ashton Research Station - Weather Generator) were used to generate future climatic data. Future land use data were also generated by the CA-Markov (Cellular Automata-Markov) method. The Soil and Water Assessment Tool (SWAT) model was used to evaluate hydrologic impacts. The SWAT model was calibrated and validated with stream flow measured at the Baran watershed in Korea. The SWAT model simulation results agreed well with observed values during the calibration and validation periods. In this study, hydrologic impacts were analyzed according to three scenarios: future climate change (Scenario I), future land use change (Scenario II), and both future climate and land use changes (Scenario III). For Scenario I, the comparison results between a 30-year baseline period (1997~2004) and a future 30-year period (2011~2040) indicated that the total runoff, surface runoff, lateral subsurface runoff, groundwater discharge, and evapotranspiration increased as precipitation and temperature for the future 30-year period increased. The monthly variation analysis results showed that the monthly runoff for all months except September increased compared to the baseline period. For Scenario II, both the total and surface runoff increased as the built-up area, including the impervious surface, increased, while the groundwater discharge and evapotranspiration decreased. The monthly variation analysis results indicated that the total runoff increased in the summer season, when the precipitation was concentrated. In Scenario III, the results showed a similar trend to that of Scenario II. The monthly runoff for all months except October increased compared to the baseline period.

• 응용통계연구
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• 제26권6호
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• pp.923-932
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• 2013

이 논문에서는 우리나라에서 발생하는 원인균별 식중독 발생건수를 예측하는 방법을 제안한다. 우리나라에서 보고되는 주별 식중독 발생 건수를 원인균로 나누면 자료에 많은 0의 관측값이 포함되어 있으며 식중독 발생 간에 종속성을 가진다. 이 현상을 모형화하기 위해 이 논문에서는 전체 식중독 건수를 자기회귀모형으로 예측하고 원인균별 식중독 발생 확률을 다범주 로짓모형으로 추정한다. 예측된 식중독 건수와 추정된 원인균별 식중독 발생 확률을 곱하여 원인균별 식중독 발생건수를 예측한다. 제안된 방법의 타당성을 확인하기 위해 평균제곱오차와 평균절대편차를 이용하여 제안 방법과 영과잉모형을 비교해 본다.

• 한국건설관리학회논문집
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• 제24권3호
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• pp.3-11
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• 2023

건설업은 노동집약적 산업으로, 성능과 생산성의 변동성이 매우 높다. 따라서 계약자의 실제 성과를 파악하기 위해 기준생산성을 정량적이고 객관적으로 산출하여야 한다. 하지만, 기존 문헌에서 주로 제시된 기준생산성 산출 방법은 주관성이 내재된 기준을 사용하여 기준생산성을 산출한다는 한계가 있다. 또한, 데이터 수집에 과도한 비용과 시간이 투입되는 기존의 'Five-minute Rating'과 같은 데이터 수집 방식으로는 공사 현장에서 실적 물량, 실적 자원과 저해 요인이 포함된 Detailed Data를 수집하기 어렵다. 이에 본 연구에서는 Unimpacted Productivity BP를 산출할 때 활용되는 Detailed Data를 체계적인 형식으로 기록할 수 있는 작업 체크시트 와 과도한 비용과 시간을 들이지 않고 데이터를 수집하고 활용할 수 있는 프로세스를 제시하였다. 또한 기존 기준생산성 산출 방법의 객관성과 신뢰도 문제를 해결하기 위해 비교 분석하여. Detailed Data를 활용한 보다 더 객관적이고 정확한 Unimpacted Productivity BP를 활용한 기준생산성 산출을 제안한다.

• 한국기후변화학회지
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• 제7권3호
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• pp.341-349
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• 2016

This study is intended to set a greenhouse gas emission scenario based on green remodeling pilot project (Annex building of Seoul Customs Office) using LEAP model, a long-term energy plan analysis model, to calculate the energy saving and greenhouse gas emission till year 2035 as well as to analyze the effect of electric power saving cost. Total 4 scenarios were made, Baseline scenario, assuming the past trend is to be maintained in the future, green remodeling scenario, reflecting actual green remodeling project of Seoul Customs Office, behavior improvement and renewable energy supply, and Total scenario. According to the analysis result, the energy demand in 2035 of Baseline scenario was 6.1% decreased from base year 2013, that of green remodeling scenario was 17.5%, that of behavior improvement and renewable energy supply scenario was 21.1% and that of total scenario was 27.3%. The greenhouse emission of base year 2013 was $878.2tCO_2eq$, and it was expected $826.3tCO_2eq$, approx. 5.9% reduced, in 2035 by Baseline scenario. the cumulative greenhouse gas emission saving of the analyzing period were $-26.5tCO_2eq$ by green remodeling scenario, $2.8k\;tCO_2eq$ by behavior improvement and renewable energy supply scenario, and $2.0k\;tCO_2eq$ by total scenario. In addition the effect of electricity saving cost through energy saving has been estimated, and it was approx. 634 million won by green remodeling scenario and appro. 726 million won by behavior improvement and renewable energy supply scenario. So it is analyzed that of behavior improvement and renewable energy supply scenario would be approx. 12.7% higher than that of green remodeling scenario.

• 한국음향학회지
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• 제40권6호
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• pp.578-586
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• 2021

종단간 음성인식기의 성능향상을 위한 변분 오토인코더(Variational AutoEncoder, VAE) 및 비교사 데이터 증강(Unsupervised Data Augmentation, UDA) 기반의 준지도 학습 방법을 제안한다. 제안된 방법에서는 먼저 원래의 음성데이터를 이용하여 VAE 기반 증강모델과 베이스라인 종단간 음성인식기를 학습한다. 그 다음, 학습된 증강모델로부터 증강된 데이터를 이용하여 베이스라인 종단간 음성인식기를 다시 학습한다. 마지막으로, 학습된 증강모델 및 종단간 음성인식기를 비교사 데이터 증강 기반의 준지도 학습 방법으로 다시 학습한다. 컴퓨터 모의실험 결과, 증강모델은 기존의 종단간 음성인식기의 단어오류율(Word Error Rate, WER)을 개선하였으며, 비교사 데이터 증강학습방법과 결합함으로써 성능을 더욱 개선하였다.

• Journal of Positioning, Navigation, and Timing
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• 제4권2호
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• pp.79-85
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• 2015

Existing Differential GPS (DGPS) pseudorange correction (PRC) generation techniques based on a virtual reference station cannot effectively assign a weighting factor if the baseline distance between a user and a reference station is not long enough. In this study, a virtual reference station DGPS PRC generation technique was developed based on an enhanced inverse distance weighting method using an exponential function that can maximize a small baseline distance difference due to the dense arrangement of DGPS reference stations in South Korea, and its positioning performance was validated. For the performance verification, the performance of the model developed in this study (EIDW) was compared with those of typical inverse distance weighting (IDW), first- and second-order multiple linear regression analyses (Planar 1 and 2), the model of Abousalem (1996) (Ab_EXP), and the model of Kim (2013) (Kim_EXP). The model developed in the present study had a horizontal accuracy of 53 cm, and the positioning based on the second-order multiple linear regression analysis that showed the highest positioning accuracy among the existing models had a horizontal accuracy of 51 cm, indicating that they have similar levels of performance. Also, when positioning was performed using five reference stations, the horizontal accuracy of the developed model improved by 8 ~ 42% compared to those of the existing models. In particular, the bias was improved by up to 27 cm.

• Journal of Preventive Medicine and Public Health
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• 제53권4호
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• pp.275-284
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• 2020

Objectives: Police officers may be at a greater risk for cardiovascular disease (CVD) than the general population due to their highstress occupation. This study evaluated how an educational program based on the health belief model (HBM) may protect police officers from developing CVD. Methods: In this single-group experimental study, 58 police officers in Iran participated in a 5-week intervention based on HBM principles. Outcomes included changes in scores on an HBM scale, time spent on moderate to vigorous physical activity (International Physical Activity Questionnaire), body mass index (BMI), blood lipid profile, blood glucose, and blood pressure. The intervention consisted of 5 HBM-based educational sessions. Follow-up was conducted at 3 months post-intervention. The paired t-test was used to examine differences between baseline and follow-up scores. Results: All aspects of the HBM scale improved between baseline and follow-up (p<0.05), except the cues to action subscale. Self-efficacy and preventive behaviors improved the most. BMI decreased from 26.7±2.9 kg/㎡ at baseline to 25.8±2.4 kg/㎡ at follow-up. All components of the lipid profile, including triglycerides, cholesterol, high-density lipoprotein, and low-density lipoprotein, showed significant improvements post-intervention. Blood glucose and blood pressure also decreased, but not significantly. Nearly 25% of participants who were not physically active at baseline increased their physical activity above or beyond the healthy threshold. Conclusions: A relatively brief educational intervention based on HBM principles led to a significant improvement in CVD risk factors among police officers. Further research is needed to corroborate the effectiveness of this intervention.