Entropy and scaling behaviors of international trade patterns

Nobi Ashadun,Milu Sharmin Akter,Lee Jae Woo 한국물리학회 2023 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.83 No.9

We investigate the impact of international commodities trade on economic growth of fve Asian countries including China over the last two decades. We examine the exports of eight commodity categories from 1995 to 2018. Firstly, we calculate trade entropy by considering the probability of exporting a product from one country to another. Our analysis reveals a signifcant increase in China’s trade entropy for manufactured goods primarily classifed by material, compared to other products. The strong correlation between changes in gross domestic product (GDP) and trade volume in China indicates a remarkable contribution of manufactured goods to GDP during the studied period. Additionally, we establish a power law-scaling relation between GDP and product exports over time. Notably, the growth of manufactured goods from China exhibits a super-linear relationship with GDP.

Does Product Familiarity and Brand Name Order Really Matter in Country of Origin Fit Effects in Brand Alliances?

Nobi, Benjamin,Kim, Kyung-Min 한국경영컨설팅학회 2017 경영컨설팅연구 Vol.17 No.2

세계화가 빠른 속도로 진행됨에 따라 브랜드제휴가 기업들의 전략으로 활발히 행해지고 있다. 기업이 브랜드 제휴를 하는 이유는 시장 다양화, 시장 침투, 시장 개발 및 제품 개발 수단으로 사용될 수 있기 때문이다. 그러나 브랜드 제휴 전략은 원산지 때문에 다소 복잡한 문제를 발생할 수 있기 때문에 마케터는 매우 신중하게 사용해야 성공적인 브랜딩 전략이 될 수도 있을 것 이다. 마케팅에서 브랜드제휴에 대한 선행 연구들은 제품의 소비자 평가가 원산지에 의해 영향 받는다는 것을 증명하였다. 그렇기 때문에 소비자들은 선진국에서 온 제품이나 브랜드가 후진국에서 나온 제품이나 브랜드에 비해 높은 평가를 받는다는 것에 대해서 당연하게 생각하는 경향이 있다. 그러나 모든 제품이 반드시 그렇지는 않을 것이다. 가령 농산품이나 특산품의 경우가 그러할 경우가 많다. 이러한 측면에서 본 연구는 브랜드 제휴와 원산지 국가의 적합성에 대한 부분을 살펴보고자 하였다. 특히, 소비자가 이러한 브랜드 제휴를 평가하는 방법에 관해서 밀도 있게 연구하였다. 구체적으로 브랜드 친숙성과 제휴 브랜드의 표기 순서(BNO; Brand Name Order)가 소비자의 브랜드 제휴의 태도에 어떠한 영향을 주는가에 대해 연구를 하였다. 연구결과, 다른 연구에 의해 입증 된 것과 마찬가지로 실제로 브랜드 제휴는 소비자의 태도에 있어 원산지 국가의 영향이 있는 것으로 판명되었다. 구체적으로 원산지적합성과 제품 친숙도는 브랜드 제휴에 주효과가 나타났지만 상호작용효과는 없었다. 또한 원산지 적합성과 제휴브랜드명의 표기순서는 영향이 브랜드 제휴에 영향이 있는 것으로 나타나 순서효과 역시 검증되었다. 뿐만 아니라 원산지 적합성과 제휴브랜드의 상호작용은 존재하는 것으로 판명되었다. Due to the fast pace nature of globalization, brand alliance efforts of companies are becoming rampant. There are various brand alliance methods that companies can engage in as means of diversification, market penetration, market development and product development. We cannot rule out the fact that brand alliance can be somewhat complex because of the country of origin factor. However, it can also be a great branding strategy. Extant research has demonstrated how consumers’ evaluation of products are affected by country of origin. Due to this, we are not surprised to learn or know that, naturally, products or brands that come from high economic status countries are highly evaluated compared to products or brands that come from low economic status countries. Of utmost interest to this study is the influential power of country of origin fit in brand alliances. Specifically, with regards to how consumers evaluate this alliance. To this end particular emphasis is placed on how product familiarity (PF) as well as Brand Name Order (BNO) moderate country of origin fit impacts on consumer’s brand alliance attitude. As a matter of fact, just as it has been proven by other studies, it was seen that, indeed consumers’ attitude towards brand alliance are affected by country of origin fit. That notwithstanding, it was also confirmed that, the relationship between attitude towards brand alliance and product familiarity was proportional. Besides, it was also seen that, the position of the brand name on the package played a role in influencing consumers’ attitude towards the brand alliance. This is regardless of whether the alliance occurred between two high country of origin fit or low country of origin fit setting.

Systemic risk and hierarchical transitions of financial networks

Nobi, Ashadun,Lee, Jae Woo American Institute of Physics 2017 Chaos Vol.27 No.6

Dynamic of consumer groups and response of commodity markets by principal component analysis

Nobi, Ashadun,Alam, Shafiqul,Lee, Jae Woo Elsevier 2017 PHYSICA A-STATISTICAL MECHANICS AND ITS APPLICATIO Vol.482 No.-

<P><B>Abstract</B></P> <P>This study investigates financial states and group dynamics by applying principal component analysis to the cross-correlation coefficients of the daily returns of commodity futures. The eigenvalues of the cross-correlation matrix in the 6-month timeframe displays similar values during 2010–2011, but decline following 2012. A sharp drop in eigenvalue implies the significant change of the market state. Three commodity sectors, energy, metals and agriculture, are projected into two dimensional spaces consisting of two principal components (PC). We observe that they form three distinct clusters in relation to various sectors. However, commodities with distinct features have intermingled with one another and scattered during severe crises, such as the European sovereign debt crises. We observe the notable change of the position of two dimensional spaces of groups during financial crises. By considering the first principal component (PC1) within the 6-month moving timeframe, we observe that commodities of the same group change states in a similar pattern, and the change of states of one group can be used as a warning for other group.</P> <P><B>Highlights</B></P> <P> <UL> <LI> The principal component analysis applied to the time series of commodity futures. </LI> <LI> The drop of the largest eigenvalue corresponds to the market crash. </LI> <LI> Groups of commodities observed during the financial crisis. </LI> </UL> </P>

State and group dynamics of world stock market by principal component analysis

Nobi, A.,Lee, J.W. North-Holland Pub. Co 2016 PHYSICA A-STATISTICAL MECHANICS AND ITS APPLICATIO Vol.450 No.-

<P>We study the dynamic interactions and structural changes by a principal component analysis (PCA) to cross-correlation coefficients of global financial indices in the years 1998-2012. The variances explained by the first PC increase with time and show a drastic change during the crisis. A sharp change in PC coefficient implies a transition of market state, a situation which occurs frequently in the American and Asian indices. However, the European indices remain stable over time. Using the first two PC coefficients, we identify indices that are similar and more strongly correlated than the others. We observe that the European indices form a robust group over the observation period. The dynamics of the individual indices within the group increase in similarity with time, and the dynamics of indices are more similar during the crises. Furthermore, the group formation of indices changes position in two-dimensional spaces due to crises. Finally, after a financial crisis, the difference of PCs between the European and American indices narrows. (C) 2016 Elsevier B.V. All rights reserved.</P>

The effect of firm’s severity of unethicality on brand trust: the role of ethical self-identity and brand relationship quality

Nobi, Benjamin,Kyung-Min Kim 한국마케팅관리학회 2019 한국마케팅관리학회 학술대회 Vol.2019 No.10

In recent times consumers are becoming more conscious of how companies’ actions affect society and consumers’ interests in corporate social responsibility cannot be overemphasized. Previous research provides empirical evidence on the relationship between a firm’s unethical behavior and brand trust. Specifically, it is known that high levels of consumer perceived unethicality reduce the level of trust consumers have for the brand in question. Consumer interests and awareness of ethical issues relating to brands is fast growing which presupposes that, companies must seek to integrate ethical behaviour into their business model (Singh, J. 2016). Extant research shows that empathy is evident with consumers’ identification with ethical issues which consequently impacts their attitudes (Shaw & Shiu, 2002; Ellen, Webb & Mohr, 2006). Also, when consumers are committed or attached to a brand, this in turn influences their attitude or judgements towards the unethical actions of firms (Schmalz & Orth, 2012; Ingram, Skinner & Taylor, V. A, 2005). When consumers have a strong relationship with a brand and feel attached, they are keener to sustain that relationship because that relationship is regarded as an investment. In their study, Tsarenko & Tojib (2012) show that, after a transgression of a firm, consumers’ decision to switch service provider was attenuated by forgiveness. Due to forgiveness, Consumers are willing to continue purchasing the firms’ products even after a transgression (Tsarenko & Tojib, 2015). Thus, the present study therefore examines how other boundary conditions - brand relationship quality and ethical self-identity affect the relationship between the severity of a firm’s unethical behavior and brand trust. A theoretical framework with hypothesized relationships is developed and tested in order to answer the research questions. We predict the following based on previous studies: H1: Brand relationship quality moderates the effects of severity of unethicality on brand trust such that, when severity of unethicality is high and brand relationship quality is high, brand trust is higher than when brand relationship quality is low. H2: Ethical Self-identity moderates the relationship between severity of unethicality on brand trust such that, when severity of unethicality is high and ethical self-identity is high, brand trust is lower than when ethical self-identity is low. Data is collected from structured questionnaires resulting in 81 valid responses. Employing Analysis of variance (ANOVA), data was analysed. The results, consistent with the hypotheses, provide evidence that, ethical self-identity interact with severity of firm’s unethicality on brand trust. More to that, band relationship quality also moderated the relationship between severity of firm’s ethicality on brand trust. The study makes appropriate contribution in the domain of business ethics. From the findings of this study, important implications for managers are drawn as well as future research directions. For instance, a closer look at the interaction effects shows that, ethical self-identity represents an important consumer trait that managers must consider when they want to gain the consumers’ trust of their brand. Also, brand relationship building provides a buffer for firms in the event of an unfortunate circumstance on the part of firms.

Integrating Indian Remote Sensing Multi-spectral Satellite and Field Data to Estimate Seagrass Cover Change in the Andaman and Nicobar Islands, India

Nobi Elavumkudi Paulose,Elangovan Dilipan,Thirunavukarassu Thangaradjou 한국해양과학기술원 2013 Ocean science journal Vol.48 No.2

Environmental resource managers and policy makers require a reliable tool to quickly assess the spatial extent of any natural resources, including seagrasses, in order to develop management plans. Even small natural or anthropogenic disturbances can cause severe changes in the distributional pattern of seagrass meadows. Satellite imageries provide a suitable means to detect and assess such changes in space and time in remote and inaccessible areas. Present study aims to understand the distribution pattern of seagrasses after the Indian Ocean Tsunami in 2004 with the help of Indian Remote Sensing satellite data and in situ ground surveys with hand held GPS. As no geospatial data bases were available for the pre-tsunami period, the changes in seagrass cover were compared with the ground estimates available in the literature and also using pre-tsunami satellite data sets. The study found severe loss of seagrasses in the northern Andaman particularly in the Interview and North reef islands and in the Nicobar group of islands including Great Nicobar and Trinket islands. The investigation revealed the presence of 2,943.38 ha of seagrass covering the entire Andaman and Nicobar islands, and that 1,619.41 ha of seagrasses had been denuded during this period. The earthquake and subsequent tsunami in 2004 was the major reason for the loss of seagrasses in these islands. The seagrass spatial map generated in the present study can be used for the development of conservation and management plans and also to restore the denuded seagrasses of this region.

Structural Changes in the Minimal Spanning Tree and the Hierarchical Network in the Korean Stock Market around the Global Financial Crisis

Ashadun Nobi,맹성은,하정균,이재우 한국물리학회 2015 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.66 No.8

This paper considers stock prices in the Korean stock market during the 2008 global financial crisis by focusing on three time periods: before, during, and after the crisis. Complex networks are extracted from cross-correlation coefficients between the normalized logarithmic return of the stock price time series of firms. The minimal spanning trees (MSTs) and the hierarchical network (HN) are generated from cross-correlation coefficients. Before and after the crisis, securities firms are located at the center of the MST. During the crisis, however, the center of the MST changes to a firm in heavy industry and construction. During the crisis, the MST shrinks in comparison to that before and that after the crisis. This topological change in the MST during the crisis reflects a distinct effect of the global financial crisis. The cophenetic correlation coefficient increases during the crisis, indicating an increase in the hierarchical structure during in this period. When crisis hits the market, firms behave synchronously, and their correlations are higher than those during a normal period.

Random Matrix Theory and Cross-correlations in Global Financial Indices and Local Stock Market Indices

Ashadun Nobi,맹성은,하경균,이재우 한국물리학회 2013 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.62 No.4

We analyzed cross-correlations between price fluctuations of global financial indices (20 daily stock indices over the world) and local indices (daily indices of 200 companies in the Korean stock market) by using random matrix theory (RMT). We compared eigenvalues and components of the largest and the second largest eigenvectors of the cross-correlation matrix before, during, and after the global financial the crisis in the year 2008. We find that the majority of its eigenvalues fall within the RMT bounds [λ_-,λ₊], where λ_- and λ₊ are the lower and the upper bounds of the eigenvalues of random correlation matrices. The components of the eigenvectors for the largest positive eigenvalues indicate the identical financial market mode dominating the global and local indices. On the other hand, the components of the eigenvector corresponding to the second largest eigenvalue are positive and negative values alternatively. The components before the crisis change sign during the crisis, and those during the crisis change sign after the crisis. The largest inverse participation ratio (IPR) corresponding to the smallest eigenvector is higher after the crisis than during any other periods in the global and local indices. During the global financial the crisis, the correlations among the global indices and among the local stock indices are perturbed significantly. However, the correlations between indices quickly recover the trends before the crisis.

Financial States of World Financial and Commodities Markets Around Sovereign Debt Crisis

Ashadun Nobi,이재우 한국물리학회 2017 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.71 No.10

We applied a threshold method to construct a complex network from cross-correlations coefficients of 46 daily time series comprised of 23 global indices and 23 commodity futures from 2010 - 2014. We identify financial states of both global indices and commodity futures based on the change of the network structure. The trend of the average correlation is decreasing except sharp peak during crises during the study period. The threshold networks are generated at a threshold value of = 0.1 and the change of degrees of each node over time is used to identify the financial state for each index. We observe that commodity futures, such as EU CO2 emission, live cattle, natural gas as well as the financial indices of Jakarta and Indonesia stock exchange (JKSE) and Kuala Lumpur stock exchange (KLSE) change states frequently. By the average change in links we identify the indices which are more reactive to crises.