Clustering and Recommendation for Semantic Web Service in Time Series

( Yu Lei ),( Wang Zhili ),( Meng Luoming ),( Qiu Xuesong ) 한국인터넷정보학회 2014 KSII Transactions on Internet and Information Syst Vol.8 No.8

Promoted by cloud technology and new websites, plenty and variety of Web services are emerging in the Internet. Meanwhile some Web services become outdated even obsolete due to new versions, and a normal phenomenon is that some services work well only with other services of older versions. These laggard or improper services are lowering the performance of the composite service they involved in. In addition, using current technology to identify proper semantic services for a composite service is time-consuming and inaccurate. Thus, we proposed a clustering method and a recommendation method to deal with these problems. Clustering technology is used to classify semantic services according to their topics, functionality and other aspects from plenty of services. Recommendation technology is used to predict the possible preference of a composite service, and recommend possible component services to the composite service according to the history information of invocations and similar composite services. The experiments show that our clustering method with the help of Ontology and TF/IDF technology is more accurate than others, and our recommendation method has less average error than others in the series of missing rate.

中國商業銀行流動性風險的決定要因

( Yu Lei ),( Kwanghyun Yu ),( Sungchul Bang ) 아시아.유럽미래학회 2013 유라시아연구 Vol.10 No.1

2006년 WTO가입을 계기로 중국의 은행 보험산업의 개방이 확대되면서 많은 외자은행들이 중국에 진출하게 되었다. 이에 따라 많은 중국 상업은행들은 치열한 경쟁 속에서 살아남기 위해 유동성을 포기하는 대가로 수익성을 추구하는 사례가 종종 나타나고 있다. 또한 2007년 미국 서브프라임 모기지 사태로 촉발된 유동성 리스크로 인해 많은 은행들과 금융기업들이 파산하게 되었으며 이는 글로벌 실물경제에 큰 영향을 미쳤다. 1978년 중국공산당 11기 3중 전회를 통해 개혁 개방 정책을 선언한 이후 중국 정부가 경제개혁 기간에 은행산업의 개혁을 추진함으로써 은행산업의 독점 국면이 점차 타파하게 되며 경쟁 시스템을 도입하게 되었다. 아시아 금융위기 무렵에 중국 은행산업에 과대경쟁으로 유동성 위기가 발생하게 되었으며 국유은행인 하이난발전은행(Hainan Development Bank)이 유동성 고갈로 파산하게 되었다. 이로 말미암아 중국인민은행(People``s Bank of China: PBC)이 약 40억 위안 손실을 입혀 중국 은행산업에 매우 큰 영향을 미쳤다. 또한, 중국은 장기적으로 무역지수 흑자와 대량 외국자본 유입의 까닭으로 은행산업에 유동성 과잉 (excess liquidity) 현상이 나타났다. 이러한 유동성 과잉 상황은 단기적으로는 시장 금리(inter-bank rate)가 은행 예금 금리보다 더 낮아지는 금리 역전현상이 나타나고 은행은 아무리 수익성이 높은 투자를 할지라도 바닥을 볼 것이며, 장기적으로는 부실채권의 누적이 가속화되어 자산 거품을 유발할 수 있으며 최종 외부의 충격으로 자산의 거품은 사라지고 상업은행의 유동성 위기가 초래될 수 있다(노진호 & 이승준, 2009). 게다가 유동성 과잉으로 말미암아 은행들 간에 과대 경쟁의 현상을 유발하며 신용 리스크와 이자율 리스크를 동반한 유동성 리스크를 촉발할 가능성도 높아진다. 한편, 중국은 한국의 최대 교역국으로서 한국 경제에 영향을 미치는 중요변수 중 하나다. 그러나 한국의 경우 중국 은행 보험산업에 잠복해 있는 다양한 불확실성으로 인해 발생할 수 있는 유동성 리스크에대한 인식 정도는 매우 부족한 편이다. 이러한 상황에서 중국 상업은행들의 유동성 위기는 중국 경제에 대한 의존도가 높은 한국에 큰 영향을 줄 수 있으며, 특히 이미 중국에 투자한 한국기업들과 지속적으로 중국 전역으로 확장을 시도하는 글로벌 금융회사들에게 직접적 영향을 미칠 수 있다. 따라서 본 연구는 중국 상업은행의 유동성 리스크에 영향을 미치는 내부적 요인과 거시 경제 요인을 실증분석하고, 은행의 자산규모별로 어떤 차이가 있는지를 분석해보고자 한다. 이를 위해 국제 은행 통계사이트인 BankScope의 데이터, 중국인민은행의 자료 그리고 중국 통계연보(China Statistical Yearbook)를 활용하여 홍콩, 마카오, 타이완 등 지역을 제외하며 중국 국유상업은행(State-owned Commercial Bank), 주식제상업은행(Joint-stock Commercial Bank) 그리고 도시상업은행(Urban Commercial Bank)을 포함한 25개 중국 상업은행을 대상으로 추정한다. 횡단면자료의 이분산과 시계열자료의 자기상관 문제로 발생하는 분산의 과소평가 문제로 인하여 패널OLS 추정방법을 사용하는 것을 타당하지 않다. 그러나 본 연구는 고정효과모형(fixed effects)모형 및 확률효과(random effects)모형과 비교하는 차원에서 먼저 패널OLS로 추정한 결과를 제시하며, 그 후 Hausman 검정에 따라 고정효과모 형과 확률효과모형을 동시에 추정하여 효율적인 모형을 위주로 분석하였다. 실증분석결과, 첫째 고정효과모형으로 25개 상업은행의 유동성을 추정한 경우, 부실채권 비율(NPL), 요구불 예금 대 총 예금 비율(CURRENT), 자기자본수익률(ROE), 자기자본비율(CAR) 등 은행 내부적요소는 중국 상업은행의 유동성에 영향을 미치지 않는 반면, 명목 이자율(R), 광의통화 변동률(M2), 소비자 물가지수(CPI) 등 거시적 결정요인들이 은행의 유동성에 (-)효과가 나타났다. 이는 중국에서 인민은행이 통화정책을 활용하여 중국 상업은행의 유동성을 조정하고 유동성 리스크를 통제할 수 있다는 것으로 해석된다. 둘째, 총자산 규모가 1조 위안을 기준으로 대행은행과 중소형은행을 구분하여 확률효과모형을 추정하였다. 따라서 대형상업은행의 유동성은 요구불 예금 대 총 예금의 비율(CURRENT), 자기자본수익률 (ROE)와 같은 은행 내부의 요소와 명목 이자율(R), 광의통화 변동률(M2), 소비자 물가지수(CPI), 2008 금융위기(CRISIS) 등 거시적 경제요인의 영향을 받을 반면, 중소형 상업은행의 경우, 부실채권 비율 (NPL), 명목 이자율(R), 광의통화 변동률(M2) 등 요소들이 상업은행의 유동성에 마이너스(-)효과가 있음을 보여준다. 즉, 은행 내부의 요소와 거시적 경제요인이 중국 대형 상업은행의 유동성에 영향을 미치나 중소형 상업은행의 유동성에 부실채권, 거시적 경제요소를 영향을 받는 것으로 추정되었다. With China’s accession to the World Trade Organization (WTO), many foreign banks have started to enter into China while Chinese banking and insurance industries have been deepening and opening up. Commercial banks will pay more attention to profit and abandon appropriate liquidity in order to survive in fierce competition. Particularly in recent years, liquidity risk caused by the US sub-prime mortgage crisis has lead banks and many financial institutions to collapse and has also been bringing the devastating impact on the global economy. In 1978, Chinese government began to implement the reform and opening up, and in the meanwhile began to reform the banking sector, which interrupted the banking monopoly and led in competition system into banking sector. During the Asian financial crisis in 1997, China’s banking sector experienced liquidity crises due to over competition, leading to the bankruptcy of Hainan Development Bank because of exhausted liquidity. The bankruptcy of Hainan Development Bank resulted in the loss of nearly 4 billion yuan of People’s Bank of China, which had a graveness influence on China’s banking sector. In addition, China’s long-term trade surplus and a large inflow of foreign capital lead to the excess liquidity in the banking sector. In the pressure of such excess liquidity, banks will blindly decrease lending rates to get inter-bank rate lower than bank-deposit rate appearing interest rate inversion phenomenon to decrease bank returns. In the long term, this will probably accelerate the accumulation of non-performing loan of bank. When the economy changes, asset bubbles of bank will quickly be shattered, which will directly result in the systematic financial crisis in the banking sector. Meanwhile, China as a largest trading partner of South Korea has been a key factor on its economy. However, South Korea is lacking of understanding of potential various uncertainties and liquidity risk in China’s Economy, which bases on banking. In this case, South Korea will be significantly influenced due to its highly dependence on China’s Economy if Chinese commercial banks suffer from liquidity risk. Especially, Korean companies already invested in China and global financial companies constantly attempting to expand all over of China should be directly affected. Therefore, this paper is to analyze the determinants of the bank’s liquidity risk in Chinese commercial banks and what difference between large commercial banks and small-medium commercial banks. The banking data used in this paper were extracted from the database BankScope IBCA-Fitch, the People’s Bank of China and China Statistical Yearbook. We used panel data of 25 commercial banks over the period from 2004 to 2011 to estimate the determinants of liquidity risk by panel OLS, the fixed effects and random effects regression. The results of the empirical analysis are as follows: first, internal factors in banks did not affect the liquidity of the commercial banks in China, but it was affected by macro-economic factors negatively. It implies that the People’s Bank of China will be able to adjust liquidity and manage liquidity risk in commercial banks in China using monetary policy. Second, in terms of asset size of banks, both internal factors in banks and macro-economic factors have influence on the liquidity of large commercial banks in China, however, small-medium commercial banks have only been affected by non-performance loans ratio and macro-economic factors.

Synthesis and densification of ultra-fine ZrC powders-effects of C/Zr ratio

Yu, Lei,Feng, Lun,Lee, Hyung Ik,Silvestroni, Laura,Sciti, Diletta,Woo, Yi Jin,Lee, Sea-Hoon Elsevier 2019 International journal of refractory metals & hard Vol.81 No.-

<P><B>Abstract</B></P> <P>The excess carbon and oxygen contents of ZrC nano-powders was controlled, and the resultant effects on the densification of ZrC was analyzed. The particle size of the synthesized ZrC powder was about 200 nm and its oxygen content was 0.49 wt%. The good results can be attributed to the rapid heating and cooling rate, the beneficial effects of current, and the relatively low synthesis temperature by using SPS (Spark plasma sintering) for the powder synthesis. The homogeneous distribution between reactants was an important factor to minimize the formation of excess carbon. With increasing the amount of carbon in the raw powder mixture, the oxygen content of ZrC powders decreased and the densification was suppressed. The decrease of excess carbon content, the presence of oxygen in the ZrC lattice, and the fine particle size promoted the sintering of ZrC ceramics without any additives at relatively low temperature and pressure (1750 °C, 40 MPa).</P> <P><B>Highlights</B></P> <P> <UL> <LI> Ultra-fine ZrC powders were synthesized using a spark plasma sintering apparatus. </LI> <LI> ZrC powder with particle size of 200 nm and oxygen content of 0. 49 wt% was obtained. </LI> <LI> The powder can be densified without additives at low temperature and pressure. </LI> <LI> Low carbon content, and the oxygen in the lattice were benefit for the densification. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Balancing between "Two Evils"

Yu Lei,Sui Sophia 한국학술연구원 2022 Korea Observer Vol.53 No.2

This paper finds that Pyongyang's nuclear issue is by no means China's "primary contradiction (top priority)" in its international relations. Chinese priority on the Korean peninsula is to keep stability and the status quo of a divided Korea rather than rush to find a resolution to the nuclear issue, which may result in a military imbalance on the Peninsula, or the collapse of the Pyongyang regime and hurt China's interest. To this end, China has adopted the strategy of making a delicate balance between pressuring and sustaining the Pyongyang regime. The paper concludes that from Chinese perspectives, a North Korea at the nuclear threshold contributes to counterbalancing US military presence in the region, maintaining a status quo of divided Koreas and helping China overcome US containment. China aspires to achieve three interconnected objectives with this strategy. This first is to sustain China's economic growth, the second to counterattack US containment, and the third to propel China's rise at the systemic (global) level.

Fast Incremental Checkpoint Based on Page-Level Rewrite Interval Prediction

Yulei Huang 한국정보처리학회 2020 Journal of information processing systems Vol.16 No.4

This paper introduces pagelevel rewrite interval prediction (PRWIP). By recording and analyzing the memory access history at pagelevel, we are able to predict the future memory accesses to any pages. Leveraging this information, this paper proposes a faster incremental checkpoint design by overlapping checkpoint phase withcomputing phase and thus achieves higher performance. Experimental results show that our new incremental checkpoint design can achieve averagely 22% speedup over traditional incremental checkpoint and 14% over the previous stateoftheart work.

Young Schema Questionnaire: Factor Structure and Specificity in Relation to Anxiety in Chinese Adolescents

Yulei Yan,Jianping Wang,Wei Yu,Li He,Tian P.S. Oei 대한신경정신의학회 2018 PSYCHIATRY INVESTIGATION Vol.15 No.1

ObjectiveaaThe goal of this study was to examine the factor structure of Young Schema Questionnaire-short form (YSQ-SF) in a sample of Chinese adolescents, and to explore which maladaptive schemas were associated with anxiety symptoms. MethodsaaYSQ-SF was administered to 983 nonclinical Chinese adolescents aged 13–17 years. Confirmatory factor analyses with weighted least squares means and variance adjusted estimation were conducted to examine the factor structure of YSQ-SF. Stepwise regression analyses were performed to identify schemas associated with anxiety symptoms. ResultsaaA bifactor model with 15 correlated factors fitted the data better than other priori defined models. Stepwise regressions showed Vulnerability to harm, Abandonment, Emotional inhibition, Subjugation, and Unrelenting standards schemas were associated with anxiety symptoms. Furthermore, different anxiety symptoms were associated with common and distinctive schemas. ConclusionaaMaladaptive schemas were already stably formed in Chinese adolescents, however there’s no robust evidence for the existence of domain. The explanatory value of maladaptive schemas for understanding psychopathology of anxiety in adolescence is discussed.

The synergistic attractiveness effect of plant volatiles to sex pheromones in a moth

Yulei Fang,Rui Zeng,Shufang Lu,Luyao Dai,Xinlong Wan 한국응용곤충학회 2018 Journal of Asia-Pacific Entomology Vol.21 No.1

The effects of plant-derived chemicals (volatiles) on the attraction of the Spodoptera litura moth to sex pheromoneswere evaluated using an electroantennogram (EAG). Neuronal responses of male moths to sex pheromonemixtures (SPs) (a 9:1 mixture of synthetic (9Z,11E)-9,11-tetraddecadienyl acetate (Z9E11-14:OAc) and(9Z,12E)-9,12-tetradecadienyl acetate (Z9E12-14:OAc)) and to SPs mixtures with eight plant volatiles (benzaldehyde,(E)-β-caryophyllene, phenylacetaldehyde, 2,6-nonadienal, benzyl alcohol, racemic linalool, longifolene,and (E)-β-ocimene) were also measured. Then, wind tunnels and field trapping bioassays were conducted todetermine the influence of plant volatiles on S. litura moth behavioral responses to SPs. The results indicated thatbenzaldehyde, phenylacetaldehyde, and benzyl alcohol significantly enhanced, and longifolene, (E)-β-caryophyllene,and (E)-β-ocimene had no significant effect on the attractions to SPs, whereas racemic linaloolsignificantly decreased the attraction of male S. litura moths to SPs throughout the olfactory pathway. 2,6-Nonadienal significantly enhanced olfactory responses, but had no significant effect on output behavior. Thesefindings provide foundations in utilization of plant volatiles and sex pheromones to manage the pest and otheragricultural pests.

Comment on New Construction of Efficient Certificateless Aggregate Signatures

Yulei Zhang,Caifen Wang 보안공학연구지원센터 2015 International Journal of Security and Its Applicat Vol.9 No.1

Aggregate signature can combine n signatures on n messages from n users into single signature, and the verifier should be convinced by the aggregate signature that n users indeed sign n messages. Since aggregate signature can greatly reduce the length of total signature and the cost of verification, it is widely used in environments with low bandwidth communication, low storage and low computability. Recently, Liu et al. [H Liu, S Wang, M Liang and Y Chen, “New Construction of Efficient Certificateless Aggregate Signatures”, International Journal of Security and Its Applications Vol.8, No.1 (2014), pp. 411-422] proposed an efficient certificateless aggregate signature scheme which is proven existentially unforgeable against adaptive chosen-message attacks. Unfortunately, Liu et al.’s new certificateless signature scheme is insecure. In this paper, giving concrete and simple attacks, we demonstrate that type II adversary key generation center can make ordinary-passive attack and malicious-active attack to forge legal certificateless signatures and certificateless aggregate signatures on any messages. Furthermore, we analyze possible reasons why key generation center succeeds in ordinary-passive attack and malicious-active attack.

중국소장 마테오리치의 세계지도

양우뢰(Yulei Yang),문상명(Moon Sangmyeoung)(번역) 한국문화역사지리학회 2012 문화 역사 지리 Vol.24 No.2

중국에 현존하는 마테오리치의 지도는 모두 세 본이다. 요녕성박물관에 소장된 목판본 『양의현람도』, 남경박물관에 소장된 채색본 『곤여만국전도』, 중국국가도서관에 소장되어 있지만 훼손된 채색본 『곤여만국 전도』이다. 본문에서는 앞의 두 지도에 관하여 소개할 것이며, 이미 잘 알려진 세 본의 조선모회본 『곤여만 국전도』와 함께 고찰할 것이다. 그 이유는 현존하는 『곤여만국전도』 채색 모회본은 분명 두 개의 직접적인 모본이 있으며, 두 모본은 원본이 있기 때문이다. 그리고 원본은 서양 선교사가 제작했을 가능성이 크다. There are three copies of Matteo Ricci’s world maps known in China. One is a wood cut copy of Liangyi Xuanlan Tu, Ricci's world map of 1603 preserved in Liaoning Museum. The Second is a colored copy of Kunyu Wanguo Quantu, the Ricci’s world map of 1602 preserved in Nanjing Museum. The Third is a remnants colored copy of Kunyu Wanguo Quantu preserved in Chinese National Museum. The paper elaborates Liangyi Xuanlan Tu in Liaoning Museum and Kunyu Wanguo Quantu in Nanjing Museum, as well as examines three copies of Korean colored editions of Kunyu Wanguo Quantu that we know, based on which to claim that there are two originals for existing colored copies of Kunyu Wanguo Quantu, whose missing parent maps might be still made by western missionaries.

Yuanchao yu Gaoli guanxi yanjiu (A study of the Yuan-Koryŏ relationship) by Oyung□uu-a (Wuyuan Gaowa). Lanzhou: Lanzhou daxue chubanshe, 2012. 223pp.

( Yang Yulei ) 서울대학교 규장각한국학연구원 2013 Seoul journal of Korean studies Vol.26 No.2