• 사회경제평론
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• no.38
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• pp.51-83
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• 2012

Consider an n goods production economy. Assume the equilibrium condition of Sraffa's price system, a balanced growth condition and the goods market clearing conditions. If both equations are given to determine a real wage rate and investment, the economic system is over-determined. It suggests that there exists no long-period equilibrium to satisfy both labor market and goods market conditions. This paper interprets this situation of over-determinacy as a disequilibrium state, and attempts to solve it through disequilibrium dynamics. It constructs a model of accumulation and real wage rates consistent with Lotka-Volterra system, and shows that the overall growth path fluctuates endogenously around a resting point of long-period disequilibrium.

• The Korean Journal of Applied Statistics
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• v.33 no.2
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• pp.185-201
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• 2020

Scenario population projection reflects the high probability of future realization and ease of statistical interpretation. Statistics Korea (2019) also presents the results of 30 combinations, including special scenarios, as official statistics. However, deterministic population projections provide limited information about future uncertainties with several limitations that are not probabilistic. The deterministic population projections are scenario-based estimates and show a perfect autocorrelation of three factors (birth, death, movement) of population variation over time. Therefore, international organizations UN, the Max Planck Population Research Institute (MPIDR) of Germany and the Vienna Population Research Institute (VID) of Austria have suggested stochastic based population estimates. In addition, some National Statistics Offices have also adopted this method to provide information along with the scenario results. This paper calculates the demographics of Korea based on a probabilistic or stochastic basis and then draws the pros and cons and show implications of the scenario (deterministic) population projections.

• Proceedings of the Korea Water Resources Association Conference
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• 2018.05a
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• pp.461-461
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• 2018

우리나라를 포함하여 전 세계적으로 기후변화로 기인하는 기상변동성 증가 등의 원인으로 물, 식량, 에너지의 시공간적 불균형이 발생할 것으로 전망되고 있다. 특히 미국 캘리포니아 2012-2015 대가뭄, 우리나라의 2013-2015 대가뭄 등 물부족의 위험 가능성이 증폭됨에 따라, 이와 관련된 에너지와 식량 등의 연계자원들도 기존의 방법과 같이 관리되고 활용하는 것에 한계점이 도달하고 있다. 기후변화와 같이 기상학적 스트레스 증가와 더불어, 국제적으로 인구증가 및 도시화가 확대될 것으로 전망되며, 한국, 미국, 중국, 인도 등에서 물안보에 대한 우려가 현실로 다가오고 있으며, 세계경제포럼(world economic forum)의 "전 지구적 위험도 인지 조사"에서도 물, 식량, 에너지 위기에 대한 심각성을 강조하고 있다. 물, 식량 그리고 에너지는 서로 밀접한 연관성을 가지고 있으며, 개별 분야에서의 문제는 그 자체의 위기로 그치지 않고 다른 타 분야의 위험도를 증폭시키는 원인으로 작용하게 된다. 과거와 다르게 교통, 물류 등의 발달로 물, 식량 및 에너지의 국가간 의존도가 더욱 증가하는 방향으로 전개되고 있으며, 세 가지 자원의 연계성 강화는 결국 상호위기를 선제적으로 대응할 수 있는 방법으로 전망된다. 따라서 물안보 및 물복지 실현을 위한 물과 에너지의 저비용, 고효율의 최적화 방안은 상당히 중요한 요인이 될 수 있다. 이를 위해 본 논문에서는 자원간 Trade-off, 평가 등 에너지소비를 줄이고 에너지 효율성을 증가하며 에너지 절약형 기술에 개발에 중점을 두는 방안을 찾아야 한다. 또한 원예시설 및 관개 기술의 개선에 따른 물과 에너지 소비량 비교 분석, 시설원예 산업의 에너지 생산성 및 절약형 기술 등 에너지-물-식량 분야의 상호연결을 정량화하고 최적화하는 방안들을 지속적으로 모색해야 할 필요가 있다.

• Journal of Internet Computing and Services
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• v.24 no.2
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• pp.67-74
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• 2023

Stock price prediction research in the financial sector aims to ensure trading stability and achieve profit realization. Conventional statistical prediction techniques are not reliable for actual trading decisions due to low prediction accuracy compared to randomly predicted results. Artificial intelligence models improve accuracy by learning data characteristics and fluctuation patterns to make predictions. However, predicting stock prices using long-term time series data remains a challenging problem. This paper proposes a stable and reliable stock price prediction method using K-means clustering-based data augmentation and normalization techniques and LSTM models specialized in time series learning. This enables obtaining more accurate and reliable prediction results and pursuing high profits, as well as contributing to market stability.

• Proceedings of the Korea Water Resources Association Conference
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• 2021.06a
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• pp.39-39
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• 2021

기상재해를 극소화하기 위해서는 그 원인이 되는 기상현상의 규모와 거동을 명확히 감시하고 분석하여 신뢰성 있는 예측정보가 제공되어야 한다. 최근 위험기상 발생빈도가 증가하여 초단기 및 위험기상 예보의 정확도 향상을 위한 고품질 레이더 정보 활용 연구가 활발하게 진행되고 있다. 레이더는 전자파를 이용하여 강우의 양과 분포, 이동특성을 관측하는 장비로써 우리나라는 초단기적 위험기상 대응능력 향상을 추진하기 위한 목적으로 첨단 성능의 이중편파레이더 관측망을 구축하고 있다. 국내 기상관측용 레이더는 기상예보(기상청), 홍수예보(환경부), 군 작전 기상지원(국방부) 등으로 각 기관이 개별적으로 설치운영 하고 있다. 본 연구에서는 관계부처에서 운영하고 있는 레이더의 합성장을 이용하여 강수장의 상관성을 기반으로 이류(advection) 특성을 도출하였다. 정확도 있는 이류특성을 도출하기 위하여 시간해상도는 10분을 적용하였으며 가우시안 필터링 기법을 적용하여 강수장 상관분석을 수행하였다. 호우와 태풍을 대상으로 강수장의 이류패턴을 추출하여 강수장의 이동방향 및 속도를 고려한 강수량 예측기법의 적용성을 평가하였다. 본 연구 결과는 격자형 강수예측정보를 제공하여 AI 홍수예보 및 수치예보 모델의 초기조건 입력 등에 활용되어 기후변동성에 따른 대국민 안전 실현을 확보하는데 기후변화 대응전략의 핵심기술로 활용될 수 있을 것으로 판단된다. 덧붙어, 4차 산업혁명에 따른 수문기상 빅 데이터(big data) 통합 플랫폼을 구축하여 고해상도 홍수대응 기술 및 GIS 및 모바일 시스템을 연계한 실시간 기후재해 예·경보가 가능할 것으로 사료된다.

• The Korean Journal of Applied Statistics
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• v.32 no.1
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• pp.69-81
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• 2019

We consider bivariate long range dependent (LRD) time series forecasting using a deep learning method. A long short-term memory (LSTM) network well-suited to time series data is applied to forecast bivariate time series; in addition, we compare the forecasting performance with bivariate fractional autoregressive integrated moving average (FARIMA) models. Out-of-sample forecasting errors are compared with various performance measures for functional MRI (fMRI) data and daily realized volatility data. The results show a subtle difference in the predicted values of the FIVARMA model and VARFIMA model. LSTM is computationally demanding due to hyper-parameter selection, but is more stable and the forecasting performance is competitively good to that of parametric long range dependent time series models.

• The Southeast Asian review
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• v.27 no.2
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• pp.155-184
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• 2017

ASEAN marking its 50th anniversary in 2017 draws hopes and concerns. There is hope for the full realization of the vision of ASEAN Community since 2015 while there are increasing concerns about the changing internal and external environments. This article reviews the process of ASEAN's community building and its external relations. First, after reviewing institutionalization and functional cooperation in 2016, it argues that there is increasing pressure for the modification of the 'ASEAN Way' mainly due to the recent political changes in some ASEAN member states. Second, this article considers the nature of ASEAN's external relation focusing on continuity rather than change. The tendency of external relations of ASEAN appears to be 'avoiding conflict' and 'status quo' while it concentrates on development cooperation. We argue that such attitude contributes to the unity of ASEAN as it is useful in searching for regional resilience which is a common goal of ASEAN power elites.

• Journal of Legislation Research
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• no.44
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• pp.655-688
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• 2013

Most of all the transfer of undertakings in such a service provision business as labour-intensive operation creates uncertainty of employment, aggravates terms of employment and breaks a trade union. However there are no regulations in Korea to protect employees from these undesirable situations. On the other hand Great Britain has introduced the concept of a transfer of undertakings by service provision change in 2006. It was intended to remove or at least alleviate the uncertainties and difficulties created by the need under TUPE 1981 and EU Directive to establish a transfer of a stable economic identity which retained its identity in the hands of the alleged transferee. In contrast to the words used to define transfer in the 1981 Regulations 'service provision change' is a wholly new statutory concept and distinguished from the economic entity. The new provisions seems to be straightforwards and the circumstances in which service provision change is established are clearly set out in Regulations. In this context there is no need for a judicially prescribed multi-factorial approach, as advanced by European Court of Justice like Spijkers test. The new concept of service provision change apply even though there are some minor difference or differences between the nature of the tasks carried on after service provision change as compared with before it. A commonsense and pragmatic approach is required and It is enough only to ask whether the activities carried on by the alleged transferee are fundamentally or essentially the same as those carried out by the alleged transfer. TUPE 2006 of Great Britain far exceeding the scope of the Acquired Rights Directive is full of suggestions as a model of legislation to secure a stable employment itself and favorable and fair conditions of employment. More active efforts are needed for lawmaking to prohibit a dismissal and vary conditions of employment for the reason of the transfer of undertakings itself.

• Journal of Korea Foundry Society
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• v.42 no.2
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• pp.83-93
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• 2022

Throughout this research course, we have analyzed the financial situation of more than 2,700 companies using credit evaluation disclosures from 2017 to 2019. The population was gathered based on the certification of Ppuri companies and Ppuri Expertise companies through the Korea National Ppuri Industry Center, accompanied by the NICE credit evaluation index. For the first time in Korea, we wanted to look at growth, profitability, and stability through financial analysis of the Ppuri industry. Through an indepth analysis, we identified operating income (rate), net income (rate), asset size, and debt ratio, along with three years of Ppuri company workers and total sales fluctuations, and looked at the financial structure per capita. In addition, financial status per person was compared by dividing Ppuri companies into six groups by employee size. Groups were 10 or fewer people, 11 to 20 people, 21 to 50 people, 51 to 200 people, 201-300 people, and 300 or more people; single individual companies were excluded for research convenience. Overall, the financial situation of Ppuri companies was judged to be in a very bad downturn, and financial indicators deteriorated over the course of the three years of investigation. In particular, the smaller the number of employees, the greater the financial fluctuations were and the worse the situations were. Among Ppuri companies, the casting industry, which is the technical starting point for the value chain of the industry, was found to also be in a very bad state, with continued workforce declines, total assets and sales reductions at severe levels, and operating income (rate) and net income (rate) also very poor. This is why we need a suitable and feasible policy direction, something that is difficult but must be allowed to develop.

• Journal of IKEEE
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• v.23 no.4
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• pp.1288-1294
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• 2019

The channel-achieving property made the polar code show to advantage as an error-correcting code. However, sufficient error-correction performance shows the asymptotic property that is achieved when the length of the code is long. Therefore, efficient architecture is needed to realize the implementation of very-large-scale integration for the case of long input data. Although the most basic fully parallel encoder is intuitive and easy to implement, it is not suitable for long polar codes because of the high hardware complexity. Complementing this, a partially parallel encoder was proposed which has an excellent result in terms of hardware area. Nevertheless, this method has not been completely generalized and has the disadvantage that different architectures appear depending on the hardware designer. In this paper, we propose a hardware design scheme that applies the proposed systematic approach which is optimized for bit-dimension permutations. By applying this solution, it is possible to design a generalized partially parallel encoder for long polar codes with the same intuitive architecture as a fully parallel encoder.