• The Journal of Asian Finance, Economics and Business
• /
• 제7권7호
• /
• pp.27-34
• /
• 2020

The study investigates herding behavior in cryptocurrencies in different situations. This study employs daily returns of major cryptocurrencies listed in CCI30 index and sub-major cryptocurrencies and major stock returns listed in Dow-Jones Industrial Average Index, from 2015 to 2018. Quantile regression method is employed to test the herding effect in market asymmetries, inter-dependency and intra-dependency cases. Findings confirm the presence of herding in cryptocurrency in upper quantiles in bullish and high volatility periods because of overexcitement among investors, which lead to high volume trading. Major cryptocurrencies cause herding in sub-major cryptocurrencies, but it is a unidirectional relation. However, no intra-dependency effect among cryptocurrencies and equity market is observed. Results indicate that in the CKK model herding exists at upper quantile in market that may be due when the market is moving fast, continuously trading, and bullish trend are prevailing. Further analysis confirms this narrative as, at upper quantile, the beta of bullish regime is negative and significant, meaning the main source of market herding is a bullish trend in investment, which increases market turbulence and gives investors opportunity to herd. Also, we found that herding in cryptocurrencies exits in high volatility periods, but this herding mostly depends on market activity, not market movement.

• 대한수학회지
• /
• 제50권4호
• /
• pp.879-897
• /
• 2013

Shannon entropy is one of the widely used randomness measures especially for cryptographic applications. However, the conventional entropy tests are less sensitive to the inter-bit dependency in random samples. In this paper, we propose new online randomness test schemes for true random number generators (TRNGs) based on the mutual information between consecutive ${\kappa}$-bit output blocks for testing of inter-bit dependency in random samples. By estimating the block entropies of distinct lengths at the same time, it is possible to measure the mutual information, which is closely related to the amount of the statistical dependency between two consecutive data blocks. In addition, we propose a new estimation method for entropies, which accumulates intermediate values of the number of frequencies. The proposed method can estimate entropy with less samples than Maurer-Coron type entropy test can. By numerical simulations, it is shown that the new proposed scheme can be used as a reliable online entropy estimator for TRNGs used by cryptographic modules.

• Asia Marketing Journal
• /
• 제18권2호
• /
• pp.1-23
• /
• 2016

People receive support from others to solve problems that are difficult to solve on their own. During service encounters, customers also receive help from other customers. Inter-customer helping is a type of Customer Citizenship Behavior (CCB), which has become more prevalent with increased use of self-service technologies (SSTs). However, not all helps are created equal. The current research investigates the effects of the two types of help, autonomy- and dependency-oriented help during service encounters. Autonomy-oriented help refers to a partial hint to the problem, whereas dependency-oriented help refers to the full solution to the problem. Through experimental studies, we provide evidence that depending on the types of help received during service encounters, customers show different levels of satisfaction toward the firm. The results from Studies 1A and 1B show that autonomy- (vs. dependency-) oriented help leads to higher customer satisfaction. In addition, the current research demonstrates the mechanism for such effect. The results from Study 2 show that the relationship between the types of help and customer satisfaction is mediated by instrumentality and anxiety, which represent cognitive and affective paths respectively.

• 대한방사선기술학회지:방사선기술과학
• /
• 제46권2호
• /
• pp.107-114
• /
• 2023

The purpose of this study was to compare the basic radiological characteristics of in-house polymer gel and commercially-available gel (BANG^TM) gel dosimeters with a spectro-photometer to use a optical computed tomography (CT) scanner. We investigated the radiological characteristics including dose linearity, absorbance spectrum, dose rate dependency and inter-and intra-reproducibility at wavelengths of 590, 600 and 630 nm. The optimal dose linearities of two gel dosimeters showed R² value of 0.939 and 0.948 at wavelengths of 590 nm and 600 nm, respectively. For two polymer gel dosimeters, there is no peak sensitivity within the range of all wavelengths in absorbance spectrum. For in-house gel dosimeter, the dose rate dependency were within 5% for all wavelengths except for the dose rate of 100 MU/min. For BANG^TM gel dosimeter, the dose rate dependency showed an error range of ±5% for all wavelengths. The inter-and intra-reproducibility of two gel dosimeters were within the range of 2.5%. We have confirmed that the two gel dosimeters was appropriate for use with a optical CT scanner.

• 정보처리학회논문지B
• /
• 제9B권6호
• /
• pp.791-798
• /
• 2002

본 논문에서는 코퍼스를 이용한 확률 의존문법 자동 생성 기술을 다룬다. 한국어의 부분 자유 어순성질과 문장의 필수적 성분의 생략과 같은 특성으로 인하여 한국어 구문분석에 관한 연구들에서는 주로 의존문법을 선호하고 있다. 본 논문에서는 기존의 어절단위학습방법에서는 학습할 수 없었던 어절 내의 의존관계를 학습할 수 있는 형태소 단위의 학습 방법을 제안한다. KAIST의 트리 부착 코퍼스 약 3만 문장에서 추출한 25,000문장의Tagged Corpus을 가지고 한국어 확률 의존문법 학습을 시도하였다. 그 결과 초기문법 2,349개의 정확한 문법을 얻을 수 있었으며, 문법의 정확성을 실험하기 위해 350개의 실험문장을 parsing한 결과 69.77%의 파싱 정확도를 보였다. 이로서 한국어 어절 특성을 고려한 형태소 단위 학습으로 얻어진 의존문법이 어절 단위 학습으로 얻어진 문법보다 더 정확하다는 사실을 알 수 있었다.

• 통상정보연구
• /
• 제17권1호
• /
• pp.241-264
• /
• 2015

본 연구는 국제산업연관표의 전후방연쇄효과를 이용하여 지난 15년간 한 중 일 3국간 산업의존도 변화를 살펴본 것이다. 분석방법으로는 아시아국제산업연관표를 이용하여 한 중 일 3국간 산업연관모형을 만든 후 영향력 계수와 감응도 계수를 분석하는 것이다. 연구결과 동북아 지역경제에서 중국의 영향력이 상승하고 일본의 영향력이 하락하는 가운데 한 중 간의 산업연관성이 매우 긴밀해지고 있다는 것이 확인되었다. 또한, 한 중 일 3국은 자국내 산업에 대한 영향력과 의존도는 감소하면서 상대국 산업에 대한 영향력과 의존도는 확대되는 산업공동화 현상을 경험하고 있는 것으로 나타났다. 그리고 상호의존도를 산업별로 살펴보면 주로 석유, 기계, 수송 장비, 무역 운송, 서비스, 공공행정 등 몇몇 산업부문에서 전후방 연쇄효과가 집중되고 있음을 알 수 있었다. 이밖에 한 중 일 3국은 서비스산업에서 전후방연쇄효과가 증가되어 왔는데, 이는 3국 무역에서 서비스의 의존성과 비중이 점점 증가하고 있다는 것을 의미한다.

• Fisheries and Aquatic Sciences
• /
• 제3권2호
• /
• pp.163-171
• /
• 2000

A series of numerical experiments are performed to examine the generation of inter-annual variations by an inertial current in an idealized semi-enclosed basin with dimension comparable to that of the East Sea. Model results indicate that the inter-annual variations dominate the kinetic energy spectrum with a peak around the time scales of 2-3 years. These variations are mostly due to the westward propagating meanders and large eddies induced by the instability of current, indicating their dependency on the eddy-resolving capacity of the model. They are generated in the interior of the basin but their energy is largely confined near the western boundary such that the east-west dimension of the basin cannot be considered as a critical factor as long as the basin covers enough western boundary region. Overall, this study suggests that the inter-annual variation observed in the East Sea is due to the meandering and large eddies induced by the instability of the current.

• 대한전자공학회:학술대회논문집
• /
• 대한전자공학회 2006년도 하계종합학술대회
• /
• pp.475-476
• /
• 2006

Recently, the demand for high density MOSFET arrays are increasing. In implementing 3-D devices to this end, it is inevitable to ion-implant vertically in order to avoid screening effects caused by high silicon fins. In this study, the dependency of drain current characteristics on doping profiles is investigated by 3-D numerical analysis. The position of concentration peak (PCP) and the doping gradient are varied to look into the effects on primary current characteristics. Through these analyses, criteria of ion-implantation for 3-D devices are established.

• Nuclear Engineering and Technology
• /
• 제52권1호
• /
• pp.87-100
• /
• 2020

Performance shaping factors (PSFs) in a human reliability analysis (HRA) are one that may influence human performance in a task. Most currently applicable HRA methods for nuclear power plants (NPPs) use PSFs to highlight human error contributors and to adjust basic human error probabilities (HEPs) that assume nominal conditions of NPPs. Thus far, the effects of PSFs have been treated independently. However, many studies in the fields of psychology and human factors revealed that there may be relationships between PSFs. Therefore, the inter-relationships between PSFs need to be studied to better reflect their effects on operator errors. This study investigates these inter-relationships using two data sources and also suggests a context-based approach to treat the inter-relationships between PSFs. Correlation and factor analyses are performed to investigate the relationship between PSFs. The data sources are event reports of unexpected reactor trips in Korea and an experiment conducted in a simulator featuring a digital control room. Thereafter, context-based approaches based on the result of factor analysis are suggested and the feasibility of the grouped PSFs being treated as a new factor to estimate HEPs is examined using the experimental data.

• 한국정보디스플레이학회:학술대회논문집
• /
• 한국정보디스플레이학회 2002년도 International Meeting on Information Display
• /
• pp.685-688
• /
• 2002

In this paper, it is reported that the anode current changes at the constantly applied gate voltages and the current-voltage (I-V) characteristics of Si, Co silicide and Mo silicide field emitter arrays (FEAs) depending on vacuum level from a $10^{-9}$ torr to a $10^{-6}$ torr. The mechanism of the robustness of anode current degradation of Mo silicide FEAs under poor vacuum conditions can be explained by the model of tolerance for the oxygen adsorption and oxidation at the silicide surface. Also, we present the changes of emitting area and work function of the emitters according to vacuum level.