Earticle

The purpose of this study is to investigate KFL students’ errors in using Korea copula i-ta in their writing assignments. In Korean classes, the Korean copula i-ta is usually simply introduced as a word equivalent to the English be-verb, and there is not much explanation beyond this. However, there are many cases when i-ta cannot be considered as a counterpart to the be-verb, since i-ta and be-verb have many different properties in terms of their meanings and functions. To investigate KFL students’ error patterns in using the Korean copula, this study examined American college students’ writing data for two semesters. Our data show that students often make errors related to meanings and to forms. Errors in meaning include confusion between i-ta and iss-ta ‘to exist’, and between i-ta and toy-ta ‘to become’; and errors in forms include orthographic error, conjugation error, and inappropriate omission. This study shows that errors of i-ta are found prevalently at all levels of proficiency; upper-level students are not exempt and often make errors as they try to produce more complex sentences. We argue that the Korean copula i-ta cannot be simply compared with the English be-verb and should be taught repeatedly and explicitly as students advance into the higher levels, so that they can speak and write Korean more fluently and naturally.

The purpose of this study is to reconsider the grammar category of "ida" by comprehensively checking the partal setting of "Ida" discussed in North and South Korea after examining the process of establishing "Ida" in North Korean grammar. In North Korea, 'Ida' was set as bakkumto(바꿈토) with '-(u)m',' and '-ki', and in South Korea, it was set as a predicative case marker. There is a similarity in North and South Korea in that the grammar category of 'Ida' is set to maintain system consistency with sentence components. However, setting "Ida" as bakkumto or a predicative case marker has problems. In this paper, it is discussed that it would be better to set it as a "dependent (assisted) adjective" according to the typological view, morphological and syntactic characteristics.

This paper examines the humanness restriction on specificational Pseudo-clefts where the pseudo-cleft clause in subject position is followed by the post-copular, clefted constituent denoting a person. We will first note that the verbs within the pseudo-cleft clause at issue are restricted to what Moltmann (2013) calls ‘verbs describing (visual, tactile, or auditory) perception’ or what Akmajian (1970) calls ‘verbs which take as subjects (or objects) either abstract nouns or human nouns.’ Since like the subject of specificational copular sentences it is substituted for by it or that, but not by he nor by she, the pseudo- cleft clause is essentially construed not as a person but as a thing. The copula is required to be present in this construction and has the role of equating/identifying the open variable provided by the pseudo- cleft clause-internal gap with the referent of the post-copular, clefted constituent. However, the pseudo-cleft clause connected to the post- copular, clefted AP/VP constituent is not entity-but property-denoting, thus being resistant to its substitution by entity-denoting pronominals such as it and that.

Questioning previous proposals that sluicing constructions detected in languages with overt wh-movement can be found in languages with optional wh-movement like Korean, this paper argues that what has been called sluicing constructions in Korean manifest critically different properties from those in English with respect to types of sluice, forms of sluice, and sensitivity to Island Effects. This also provides a novel view on the presence of 'be' in sluicing-like constructions based on its optionality of its presence. Expanding a view that canonical Island Effects are from processing difficulty, this paper argues that acceptability of sluicing-like constructions that include islands is graded depending on discourse context, morphological-semantic relevancy, and anti-ambiguity requirements

SCM의 관리 포인트가 공급중심에서 수요관리 중심으로 옮겨짐에 따라, 정확한 수요 예측을 위한 많은 기 법들이 제시되어 왔다. 이 중 변수간의 인과관계 분석을 통한 수요예측이 많이 이루어지고 있음에도 불구하고, 연관 된 변수들 간의 상관구조는 상관계수에 의존하였고, 이는 예측의 정확성을 저하시키는 요인으로 작용하였다. 본 논문 에서는 기존 방법의 문제점들을 보완하며, SCM에서 발생하는 Heavy Tail형 데이터의 상관구조를 정밀하게 모델링할 수 있는 방법을 제시한다. 상관구조를 파악할 수 있는 프레임웍인 코플라 함수 중에서 Student's t-코플라 함수를 통 하여 수요 예측모형을 수립하고, 관련 파라미터를 추정하는 기법을 실험과 함께 제시하였다. 이를 통해, 수요예측에 필요한 변수들 간의 상관구조 파악이 보다 명확해지며, 이는 SCM상의 채찍효과의 완화로 이어져, 안정된 공급 사슬 네트웍의 관리에 기여할 것으로 기대된다.

As the demand-oriented management has been getting important in Supply Chain Management (SCM), various forecasting methods have been suggested including regression analyses. However, dependency structures among variables have been captured by a correlation coefficient, only. It results in inaccurate demand predictions. This paper suggests a new and effective forecasting modeling framework using student's t-copula function. In order to show overall modeling procedures framework, heavy tail typed numerical data and its copula estimations are provided. The suggested methodology can contribute to decrease the bullwhip effect and to stabilize volatile environment in a supply chain network.

본 논문은 극단치이론 중의 POT(Peaks-Over-Threshold)모형과 Copula를 이용하여 1990년 1월 3일부터 2005년 1월 20일까지의 미국, 일본, 싱가포르, 홍콩, 한국, 대만의 주요 주가지수를 대상으로 전체기간(1990.1.32005.1.20) 및 외환위기 이전(1990.1.31997.9.30)과 이후(1998.4.12005.1.20)의 상호의존성에 대한 연구를 실시하였다. 주요 연구결과를 요약하면 다음과 같다.첫째, 의존성 통계량을 종합해보면 전체기간의 경우 아시아지역 시장 간 극단적 의존관계가 존재한다는 것을 확인할 수 있지만 미국과 아시아 주식시장 간 극단적 의존성이 있다고 보기가 어렵다. 둘째, 홍콩시장과 싱가포르시장 간의 극단적 상관성이 가장 높게 나타났고, 반대로 대만증시가 아시아 기타 증시와의 극단적 의존성은 상대적으로 낮게 나타났다. 대만증시가 아시아 기타 증시와 ‘탈동조화(차별화)’ 현상의 가장 큰 원인은 대만증시의 7% 상하한 규정 때문인 것으로 보고 있다. 셋째, 외환위기 전후를 비교해보면 외환위기 이전에는 홍콩-싱가포르, 홍콩-일본, 싱가포르-일본 시장 간 극단적 의존성이 존재하지만 다른 주식시장들 간 극단적 의존성이 없다고 본다. 외환위기 이후는 외환위기 이전에 비해 시장 간의 극단적 의존성이 두드러지게 증가한 것으로 나타났다. 넷째, 양쪽 꼬리의 의존정도는 일관적으로 어느 쪽의 의존성이 크다는 것을 발견하지 못했다.

Using the concept of extreme value theory and copula, this paper shows how to estimate association across financial markets. We select Peaks-Over-Threshold(POT) method and use Generalized Pareto Distribution(GPD) as the marginal distribution. We use the most popular used Gumbel copula as well as other three copulas. We fit these copulas to daily stock index returns of six countries and use upper and lower tail dependence to identify and quantify the tail dependence among stock returns.Empirical result show that asymptotic dependence exist between Asian-Pacific markets. And such extremal dependence become stronger after Asian Financial Crisis. But we failed to detect asymptotic dependence between US and Asian-Pacific markets.

본 연구는 Copula-VaR모형을 사용하여 외국인 투자자(일본, 중국, 독일, 영국 및 미국)의 관점에서 KOSPI200에 투자한 경우 부담하게 되는 시장위험을 분석하였다. 2004년부터 2013년까지 일별 데이터를 이용하였으며 비모수적 방법으로 추정한 VaR와 Copula함수를 사 용하여 추정한 VaR의 차이도 비교 및 분석하였다. 분석 결과를 요약하면 다음과 같다. 첫째, 환율변동으로 인한 외환위험은 화폐별로 다양하지만 대체로 전체 위험의 17%~30%를 차지하는 것으로 확인 되었다. 둘째, 비모수적 방법으로 추정한 VaR 값에 비해 Copula적 방법으로 추정한 VaR값이 2%~9%정도 크게 추정되는 것으로 나타났으며 신뢰수 준이 높아질수록 그 차이가 커지는 것으로 나타났다. 마지막으로 Kupiec모형을 이용한 사후검증부분에 서는 여러 모형간의 VaR값들의 차이를 확인하였으며, 90% 신뢰수준에서는 VaR를 과대 추정하는 문 제가 있는 것으로 나타났고 99% 신뢰수준에서는 VaR를 과소 추정하는 문제가 있는 것으로 나타났다.

Sequential decision-making in dynamic, heterogeneous environments is often hindered by multivariate and correlated outcomes. This study introduces a unified Copula-CNN-LSTM Deep Q-Network (DQN) framework for multi-stage individualized policy learning in pseudo temporal settings. Motivated by the need for agents that account for inter-outcome dependencies, we extend static covariates from benchmark datasets (Boston Housing and Wine Quality Red) into pseudo-temporal sequences to emulate state transitions. Multivariate rewards with controlled correlations (ρ = 0.5 and ρ = −0.5) are standardized via an empirical copula transformation to assess policy robustness under varying dependency structures. The DQN agent optimizes policies using experience replay and temporal discounting of state-action reward trajectories. The framework demonstrates stable convergence in average rewards across both datasets under positive and negative correlation structures. Analysis of the resulting dynamic conditional average treatment effects (CATEs) across outcome dimensions highlights the model’s ability to discern heterogeneous treatment impacts. Furthermore, learned policy matrices and dynamic Directed Acyclic Graphs (DAGs) reveal interpretable temporal dependencies, with edge structures reflecting the complex multivariate nature of the optimal policy. Overall, the proposed framework effectively captures inter-temporal dependencies and adapts to correlated rewards, providing a scalable and interpretable solution for sequential decision making in complex environments.

The purpose of this research is twofold: firstly, it is to clarify the syntactic and semantic status of the copula be; secondly, it is to see how much light the copula be and argue that the copula be is light enough to be a null copula at the position of a light verb v of vP without a specifier. I argue that the copula be is an impoverished category and the lightness of copula be is a pure instantiation of a functional head v, in which a little v introduces verbal predicates as well as external arguments. The proposal in this paper is supported by synchronic and diachronic data. The optional existence of the null copula in synchronic grammatical diversities like child acquisition, standard English casual speech, journal headlines, rhetoric, and African American Vernacular English (AAVE) is discussed to prove the lightness of copula be. Diachronically, the grammaticalization shows that the null copula can be a by-product of copularization in the unidirectionality of grammaticalization in English.

은행 주가수익률의 의존성 리스크 측정은 금융 시스템의 안정성을 평가하는 데 중요한 의의를 가지며, 특히 재정 위기 및 COVID-19와 같은 사건 발생 시에 그 가치가 더욱 커진다. 좀 더 정확한 의존성 리스크 측정을 위 해 본 연구에서는 전통적인 선형 상관관계 분석보다 더 발전된 분석방법을 도입하여 시스템적 리스크를 추정하 였다. 구체적으로, 다변량 분포를 모형화하는데 적합한 copula 함수 중 vine copula를 사용하여 5개로 분류된 미 국 상업은행의 주가수익 포트폴리오로부터 포트폴리오 간 다변량 의존 구조를 분석하였다. 더 나아가, 대칭 및 비대칭 이변량 copula 패밀리를 사용하여 vine 구조에서 조건부 꼬리 의존성을 모형화하고자 하였다. 이를 통해, 본 연구에서는 선형 상관관계 접근 방식이 포트폴리오 간 의존성 리스크의 정도를 과대평가할 가능성이 있음을 발견하였다. 게다가, 비대칭 조건부 꼬리 의존성에 대한 실증분석 결과를 제시하며, 경기가 호황일 때가 불황일 때 보다 의존성 리스크가 더 높다는 것을 보였다. 앞으로 코로나19나 금융위기와 같은 금융시장의 충격이 발생했 을 때 투자자나 정책당국이 copula 방법론에 기반하여 은행부문의 상호의존성과 시스템적 리스크를 측정하고, 이 를 토대로 금융 리스크 관리와 포트폴리오 구성에 활용할 수 있을 것이다.

Measuring the dependence risk of bank equity returns is valuable for gauging the stability of the financial system, particularly during periods of financial crises and events such as the COVID-19 pandemic. To achieve this objective, we introduce a more advanced approach than a simple linear correlation to evaluate the dependence risk. This study delves into the assessment of dependence risk among bank equity returns, categorized into 5 portfolios. Specifically, we analyze the multivariate dependence structures of these portfolios through the application of a vine copula. Moreover, symmetric and asymmetric bivariate copula families are used to thoroughly analyze conditional tail dependence in the vine structures. We find that any linear correlation approaches are likely to overestimate the strength of dependence risk among the portfolios. In addition, we present empirical evidence on asymmetric conditional tail dependence, showing a stronger dependence risk in the bull market than in the bear market. These findings provide investors with more accurate information on financial risk management and portfolio construction beyond a simple linear correlation approach.

Benefits of international diversification heavily rely on the degree of dependence across securities. In this paper, we extend the results of Garcia and Tsafack (2007) regime switching mixed copula model to include Asian countries and explain the effect of exchange rate risk on the asymmetric dependence. Bootstrapped likelihood ratio tests show that asymmetric dependence of international market appears mostly insignificant when there is no exchange rate risk, while it appears significant with the presence of exchange rate risk. We suggest unwinding of foreign investment as one possible reason for these results.

In recent years, the Chinese market has entered a new opening up era. In the background of financial deepening and liberalization, financial innovation is a new profit growth point for financial institutions. As the capitalization-weighted stock market index, which is designed to replicate the performance of top 300 stocks traded in the Shanghai and Shenzhen stock exchanges, CSI 300 Index will also become the standard product or reference for more financial multiple derivatives. The existing research on the anti-manipulation and stability of CSI 300 index mainly focuses on the influence of the stock weight on the index, which often ignores the impact of the weight share price change on the stock index. In actual transactions, it is easier to exert influence on the index by manipulating the prices of the heavyweight. Therefore, it is important to study the correlation between the index and weight stocks, especially tail dependence. This paper uses the Copula function instead of a simple linear correlation function because there is no specific hypothesis on the distribution state of the data sequence when describing the relationship between two financial variables. It is a good solution to the problem that the relevance of financial variables cannot be depicted by the general linear functions in excessive volatility period. After comparing different forms of the Copula function, this paper selects the t-Copula function as the research tool and constructs the tail correlation measure. Then, the stock price time series sample is selected from the top ten weight shares of CSI 300 index from January 2015 to December 2016, including China Ping An (601318), China Merchants Bank (600036), CITIC Securities (601998), Minsheng Bank (600016) and Vanke A (000002). The AR (n) -XARCH model is used to deal with the autocorrelation and the ARCH effect of CSI 300 index and the time series of the daily returns of the five weight shares, whose resulting sequence is transformed by the probability integral. From the obtained correlation coefficient, it can see that the correlation between the CSI 300 index and the five weight stocks is relatively high. In view of this, this paper provides some suggestions:1) the weight share selection mechanism of the stock index should be optimized; 2) CSI 300 index should be strengthen supervised to reduce the manipulated volatility, which further promote the stable operation of the financial market.

본 연구는 국내 시중은행의 통합위험 측정시 시장위험과 신용위험간에 존재하 는 포트폴리오이론에 따른 분산효과에 대해서 실증적으로 검증하였다. 이를 위하여 최근 통합위험 측정에 있어서 연구되고 있는 하향식 통합위험 측 정방식, 즉 시장위험과 신용위험의 위험분포도를 도출하고 이들 특성을 유지하 면서 결합하는 측정방식을 사용하였다. 한편 비교모형으로는 금융회사의 내부모 형을 통해 산출되는 시장위험과 신용위험의 단순합산, 그리고 실무에서 많이 사 용되는 위험액 자체에 임의의 상관관계를 고려하는 단순통합모형을 사용하였다. 실증분석에서 시장 및 신용위험 등 위험유형별 위험을 산출하고 코플라 함수 를 이용하여 ‘09.3월말을 기준으로 국내은행에 대한 통합위험을 산출한 결과 내 부모형의 단순합산에 비해 분산효과가 31.3%로 추정되어 위험의 분산효과가 존 재하는 것으로 나타났다. 포트폴리오이론에 따르면 위험유형별 분산효과뿐만 아니라 위험유형간에도 분 산효과가 존재한다는 사실을 시사하고 있는데, 본 연구는 실증적 검증을 통하여 위험유형간에 분산효과가 존재하고 있음을 확인하고 있다. 이러한 결과는 향후 자기자본규제뿐만 아니라 이론적으로나 실무적으로 중요한 의미를 가지며, 감독 당국을 포함한 모든 시장 참가자들의 지속적으로 관심을 가져야 할 것으로 판단 된다.

One of the representative prudential regulations is the capital regulation. The current regulation and international criteria are just simply adding up the market risk and credit risk. According to the portfolio theory due to diversification effect the total risk is less than the summation of market and credit risk. This paper investigates to verify the existence of diversification effect in measuring the integrated risk of financial firm by the copula function, which is combine the different distribution maintain their propriety. The result of the test shows that in measuring the integrated risk not only the correlation and but also the proprieties of market and credit risk distribution are very important. And the tail of risk distribution is important when measuring the economic capital, especially the external impact to the financial market. This paper's contribution is that the empirical evidence in considering the relationship between market and credit risk the integrated risk is less than sum of them.

Park, Myung-Kwan & Li, Zhen-Xuan. 2014. Copula and ‘Sluicing' Constructions in Korean, Chinese, and Japanese. Korean Journal of Linguistics, 39-3, 427-452. This paper starts with resolving the categorial mismatch in the Cleft construction between the subject cleft clause and the focal pivot/question phrase survivor that are linked by the copula. We propose that the Cleft construction universally has bi-clausal structure, where the second cleft clause (which is the complement of the copula) undergoes ellipsis after the focal pivot/question phrase survivor extracts out of it. This conception of Cleft provides an optimal account for the language-particular distributions of the copula in embedded or matrix‘Sluicing' in East Asian languages such as Korean, Chinese, and Japanese. It also captures the optional occurrence of the pronoun subject that replaces the first cleft clause. In addition, Case marker or pre-/post-position drop or retention and the distribution of adjectival question phrases before the copula follow from the proposed analysis. All in all, the unified Cleft analysis of‘Sluicing' is shown to be effective in understanding ‘Sluicing' in the three languages. (Dongguk University)

This study introduces the following English amalgam cleft and attempts to offer an adequate analysis for this construction: He needs a break is what he needs. One popular analysis posits a Topic-Comment structure in which this sentence consists of two independent finite clauses linked by the copula is. This study, however, observes that the apparent finite clause preceding the copula displays the properties of the root clause and thus claims that this part is not really an independent clause linked with the following wh-clause. Under the Topic-Comment analysis, the copula is regarded as a Topic marker. But this study claims that it is a usual copula that appears in clefts in general. The analysis that reflects the above claims is offered as follows: He needs [FocP a break [TP pro is [what he needs] TP] FocP]. This structure well captures the fact that the [DP a break] is understood as the direct object of the matrix verb need as well as the subject of the copula is. The discussion of the study advocates for the direct complementation analysis involving FocP, against the previous Topic-Comment analysis. Further, this study extends the proposed analysis to a similar construction named subject contact relatives, showing that amalgamation of the two apparent clauses is in fact widely made through FocP complementation.

The purpose of this study is to re-examine the ‘i’ category as adjective focused on the negational form of the ‘derivational noun(N+적)+ida’. In the previous studies, the negational form of ‘ida’ has been regarded as ‘anida’ exclusively, however, the predicative nucleus of ‘ida’ construction is not ‘i’ but the element before ‘i’, therefore the negational form of ‘i’ can be changed according to the preceding element of ‘i’, such as ‘-지 않-’ in the case of ‘derivational noun(N+적)’. ‘derivational noun(N+적)’ is the most marked among the nouns which are located before ‘i’, it has adjectival meaning due to ‘-적’ and shows the long negational form ‘-지 않-’ like adjective. Although the ‘i’ shows the characteristics of adjective like long negational form, the word class of ‘i’ can not be adjective. The reasons are such as followings: First, the preceding element of ‘i’, such as ‘derivational noun(N+적)’ is the morphological and syntactical nucleus, so the ‘i’ is not the lexical category, but the functional category. Second, there are great differences between the general adjectives and ‘i’. Third, ‘derivational noun(N+적)+ida’ corresponds to adjective or verb from the perspective of contrastive linguistics, so the ‘i’ solely cannot be adjective excluding ‘derivational noun(N+적)’. Fourth, if the copula ‘i’ would be adjectives, it disagrees with the characteristics of the korean language as verb-like adjectives which functions as predicate without copula.