Vector Quantized Bayesian Neural Network Inference for Data Streams

Bayesian neural networks (BNN) can estimate the uncertainty in predictions, as opposed to non-Bayesian neural networks (NNs). However, BNNs have been far less widely used than non-Bayesian NNs in practice since they need iterative NN executions to predict a result for one data, and it gives rise to prohibitive computational cost. This computational burden is a critical problem when processing data streams with low-latency. To address this problem, we propose a novel model VQ-BNN, which approximates BNN inference for data streams. In order to reduce the computational burden, VQ-BNN inference predicts NN only once and compensates the result with previously memorized predictions. To be specific, VQ-BNN inference for data streams is given by temporal exponential smoothing of recent predictions. The computational cost of this model is almost the same as that of non-Bayesian NNs. Experiments including semantic segmentation on real-world data show that this model performs significantly faster than BNNs while estimating predictive results comparable to or superior to the results of BNNs.Comment: AAAI 202

Source signatures from combined isotopic analyses of PM2.5 carbonaceous and nitrogen aerosols at the peri-urban Taehwa Research Forest, South Korea in summer and fall.

Isotopes are essential tools to apportion major sources of aerosols. We measured the radiocarbon, stable carbon, and stable nitrogen isotopic composition of PM2.5 at Taehwa Research Forest (TRF) near Seoul Metropolitan Area (SMA) during August-October 2014. PM2.5, TC, and TN concentrations were 19.4 ± 10.1 μg m-3, 2.6 ± 0.8 μg C m-3, and 1.4 ± 1.4 μg N m-3, respectively. The δ13C of TC and the δ15N of TN were - 25.4 ± 0.7‰ and 14.6 ± 3.8‰, respectively. EC was dominated by fossil-fuel sources with Fff (EC) of 78 ± 7%. In contrast, contemporary sources were dominant for TC with Fc (TC) of 76 ± 7%, revealing the significant contribution of contemporary sources to OC during the growing season. The isotopic signature carries more detailed information on sources depending on air mass trajectories. The urban influence was dominant under stagnant condition, which was in reasonable agreement with the estimated δ15N of NH4+. The low δ15N (7.0 ± 0.2‰) with high TN concentration was apparent in air masses from Shandong province, indicating fossil fuel combustion as major emission source. In contrast, the high δ15N (16.1 ± 3.2‰) with enhanced TC/TN ratio reveals the impact of biomass burning in the air transported from the far eastern border region of China and Russia. Our findings highlight that the multi-isotopic composition is a useful tool to identify emission sources and to trace regional sources of carbonaceous and nitrogen aerosols

Methylsulfonylmethane Suppresses Breast Cancer Growth by Down-Regulating STAT3 and STAT5b Pathways

Breast cancer is the most aggressive form of all cancers, with high incidence and mortality rates. The purpose of the present study was to investigate the molecular mechanism by which methylsulfonylmethane (MSM) inhibits breast cancer growth in mice xenografts. MSM is an organic sulfur-containing natural compound without any toxicity. In this study, we demonstrated that MSM substantially decreased the viability of human breast cancer cells in a dose-dependent manner. MSM also suppressed the phosphorylation of STAT3, STAT5b, expression of IGF-1R, HIF-1α, VEGF, BrK, and p-IGF-1R and inhibited triple-negative receptor expression in receptor-positive cell lines. Moreover, MSM decreased the DNA-binding activities of STAT5b and STAT3, to the target gene promoters in MDA-MB 231 or co-transfected COS-7 cells. We confirmed that MSM significantly decreased the relative luciferase activities indicating crosstalk between STAT5b/IGF-1R, STAT5b/HSP90α, and STAT3/VEGF. To confirm these findings in vivo, xenografts were established in Balb/c athymic nude mice with MDA-MB 231 cells and MSM was administered for 30 days. Concurring to our in vitro analysis, these xenografts showed decreased expression of STAT3, STAT5b, IGF-1R and VEGF. Through in vitro and in vivo analysis, we confirmed that MSM can effectively regulate multiple targets including STAT3/VEGF and STAT5b/IGF-1R. These are the major molecules involved in tumor development, progression, and metastasis. Thus, we strongly recommend the use of MSM as a trial drug for treating all types of breast cancers including triple-negative cancers

Bank risk-taking, regulations and market discipline : three essays

textIn the first chapter, I analyze how early corrective actions affect bank risk taking and welfare of agents in an economy. Early corrective actions considered in this paper are classified into two categories: early closure and (early) recapitalization. It is shown that early closure might be preferable to save government expenses (explicit costs), but it causes inefficient bank risk-taking (implicit costs). It is not obvious whether the resolution costs and inefficiency in bank risk taking are smaller under recapitalization. However, there is a type of recapitalization in which not only does the government incur no resolution costs, but also recapitalization might reduce inefficiency. This type of recapitalization gives better ex ante expected returns so that there is Pareto improvement. The second chapter examines market discipline in the Korean banking system. Evidence of strong market discipline is essential to justify the cession of government regulatory control to the market. Two types of markets are tested: (i) the market for uninsured liabilities, and (ii) the market for bank equity. I find week evidence of market discipline in the market for uninsured liabilities in Korea. In the case of the market for bank equity, no evidence of market discipline is found. Overall, the estimation results in the two markets do not provide strong evidence of market discipline in the Korean banking system during the sample periods. In the third chapter, I examine the relationship between bank size, diversification and risk in Korean banks. Recent mergers in the Korean banking industry show that the government encourages and supports banking consolidation in various ways as a part of restructuring the financial sector. This policy trend is based on the presumptions that bigger banks are better diversified than smaller banks, and that diversification can potentially reduce the probability of failure. I test this conventional wisdom. The estimation results provide strong evidence of the positive relationship between bank size and diversification; bigger banks are better diversified than small banks. However, the results show that bigger banks’ diversification, at least in bank loans, does not generate enhanced safety in Korean banks. This suggests the possibility of the “too-big-to-fail” (TBTF) moral hazard incentives that could drive large banks to hold diversified but riskier asset portfolios.Economic

(2010) 경제발전경험모듈화사업 : 민간부문 개발

In Korea, full-fledged industrialization policies began in 1961 when President Park Chunghee took office. During the course of industrialization, the most frequently utilized policies for corporate support included the finance and tax measures over which the government had a strong control. The financial support policies under the Park Administration included the export finance of the 1960s and the financial support for the heavy and chemical industries(HCIs) of the 1970s. For export finance, the automatic loan approval system played an important role. Additionally, export financing by the banks was supported by re-discount of the Bank of Korea. For the promotion of HCIs, policy loans were concentrated on the HCI sector, while the National Investment Fund(NIF) was established to utilize domestic savings for HCI investment. During the early stages of development, the financial supports were provided to the exporting companies, and the HCIs played a critical role in advancing industrialization of Korea in a short period. These policies also had served as a substitute for the underdeveloped financial market of the time. However, the Korean economy had to suffer from chronic inflation caused by monetary expansion as it developed. In addition, the government’s financial control also brought a harmful side effect that undermined the development of the financial industry. In the 1960s - the early stages of the industrialization - tax policy was focused on the increasing of tax revenues to secure the financial resources required for the economic development. While the corporate tax rate was maintained at high to increase tax revenues, various tax reduction schemes were also in places as incentives to boost exports. Entering 1970s when the government embarked on the policy to foster HCIs, the focus of tax policy shifted from direct taxes to indirect ones so that capital accumulation in the corporate sector could be accelerated. Especially, lowering the corporate tax rate was highly regarded as a significant contributor to the formation and the rapid growth of the private capital. In addition, the introduction of the value-added tax simplified consumption taxes and enhanced efficiency to a great extent, by improving the taxation neutrality among industries. On the other hand, the tax reduction and exemption system executed to nurture HCIs and to support exports has often been criticized to have caused an over-investment in HCIs via an inefficient allocation of resources among industries. At the turn of the 1980s, after the Park administration, the government policy began to prioritize the stability over the growth. With the change in the policy direction from growth to stability, the taarge of the policies to promote businesses was changed from large enterprises to the small-and-medium-ones, and is applicable until today. In terms of financial support to small-and-medium-sized enterprises(SMEs), some policies rely on market intervention like the regulation of mandatory lending by commercial banks to SMEs. But government support to SMEs is mostly provided through the policy loans. In order to promote SMEs, corporate tax benefits and support are also provided. The SME support system greatly contributed to the startups and the promotion of the SMEs, but came under criticism for emphasizing equity rather than efficiency resulting in another kind of inefficient resource allocation. Since the late 1990s, the government has focused its support on the venture businesses based on IT, the national strategic industry. In fostering the venture businesses, the policies also promoted equity financing through KOSDAQ. This approach was taken in order to spur risk sharing in the capital market and to expand the long-term fund for the venture business. Although the number of venture businesses increased exponentially, following these friendly measures, many of them went to bankruptcy due to the over-investment. As the result, the investors faced great financial losses at the consequent collapse of KOSDAQ market. Since then, the financial support system for venture businesses has relied less on direct support and has put greater emphasis on raising capital through “Fund of Funds(FOF)”. One of the remarkable policy changes since the 1980s is that the industry supportive policies shifted from the target-based, selective one to the function-based, general one. For industries that meet performance standards in terms of productivity improvement, energy strategy and etc., they were eligible for the same support. Therefore, policy support was not determined by the government but by the market, which resulted in substantially higher efficiency of the resource allocation. Furthermore, revolutionary tax support for venture businesses was introduced after the 1997 Asian Financial Crisis, which resulted in the growth of IT industries, venture capital, and the equity market(KOSDAQ). Meanwhile, even though various tax support measures were introduced temporarily with sunset provisions to promote venture businesses, the types of policy support continued to increase as time went on. Even after achieving the intended goals, a certain categories remained in the system. This implies that the venture businesses support system was not focused or selective, but rather impartial. Therefore, it resulted in the increased complexity in the tax system and the decreased tax base.Chapter 01 Financial and Tax Support for Promoting Businesses Summary (12P) 1. Introduction (14P) 2. Supporting Export-led Growth Strategy (15P) 3. Promoting Heavy & Chemical Industries (26P) 4. Promoting Small & Medium-sized Enterprises (38P) 5. Promotion of Venture Companies (48P) 6. Assessment (56P) References (63P) Chapter 02 Korea’s Experience in Regulatory Reform and Achievements Summary (66P) 1. Background on Regulatory Reform (68P) 2. History of Korea’s Regulatory Reform (69P) 3. Periodical Changes in the Regulatory Reform Apparatus (74P) 4. Changes in the Regulatory Management System (83P) 5. Representative Measures to Conduct Regulatory Reform (87P) 6. Conditions of Successful Regulatory Reform (91P) 7. Achievements and Tasks in Regulatory Reform (96P) References (101P) Chapter 03 Manifestation of Korean Entrepreneurship and Its Achievement Summary (104P) 1. Introduction (106P) 2. Enterprise, Entrepreneur, Entrepreneurship (107P) 3. Entrepreneurship, Internal and External Environment and the Role of Government (108P) 4. Economic Development of Korea and Entrepreneurship (111P) 5. Manifestation of Entrepreneurship in Korea and Its Achievements (129P) 6. Conclusion (144P) References (146P

Heat Dissipation of Open-Cell-Type Aluminum Foams Manufactured by Replication-Casting Process

Open-cell-type aluminum foam demonstrates excellent heat dissipation owing to interconnected pores. In this study, open-cell-type aluminum foams with various pore sizes and porosities were fabricated using the replication-casting process, which is a relatively simple process. The porosity of the manufactured foams ranged from approximately 55% to 62%. To assess the heat dissipation of the manufactured foams, an air-cooling system was designed. The device could pass a controlled amount of air through the connected pores, simultaneously measuring pressure drop ∆P and temperature changes. It was confirmed that the open-cell-type aluminum foams exhibited a very high cooling rate in the initial cooling phase, and the thermal behavior is influenced by structural characteristics. At a porosity of 62%, the initial maximum cooling rate was measured to be 1.41 ℃/s for a pore size of 0.7~1.0 mm, and it was observed to significantly increase to 3.82 ℃/s for a pore size of 2.8~3.4 mm. Furthermore, for the same pore size, an increase in porosity resulted in an increase in the initial cooling rate. Lager pore sizes and higher porosities led to lower pressure drop ∆P and improved airflow, enhancing the cooling efficiency of open-cell-type aluminum foams