• Title/Summary/Keyword: 그래프

Search Result 3,939, Processing Time 0.028 seconds

An Empirical Study on the Characteristics of Stock Returns in Chinese Stock Market -Focusing on the period of 1995 to 2007 - (중국 주식시장의 수익률 특성에 관한 실증연구 - 1995년부터 2007년 기간을 중심으로 -)

  • Kim, Kyung Won;Choi, Joon Hwan
    • International Area Studies Review
    • /
    • v.13 no.3
    • /
    • pp.287-308
    • /
    • 2009
  • This article examines the distributional characteristics of the return of Chinese stock market indices. The majority of previous empirical researches have tended to focus upon the simple stock market index. However, this study focuses on the four indices which represent the characteristics of each stock market index. The empirical findings indicate that the returns of the four chinese indices are not normally distributed at conventional levels. The Ljimg-Box -statistics indicate the returns of the index of A shares are not serially autocorrelated. However, the returns of the index of B shares are serially autocorrelated. The empirical findings also indicate returns of the four chinese indices are not serially autocorrelated. The statistics of Regression Specification Error Test and ARCH indicate the returns of all four indices are not serially linear. The findings also indicate that E- GARCH model is the most fittest model for the returns of the four chinese indices and the forecast error can be reduced by using student t distribution rather normal distribution.

On Franco Moretti's World Literature: Seen from the Perspective of Periodical Studies (프랑코 모레티의 세계문학론 비판 - 매체론의 관점에서 -)

  • Lee, Jae-Yon
    • Cross-Cultural Studies
    • /
    • v.48
    • /
    • pp.325-359
    • /
    • 2017
  • The works of a literary and cultural historian Franco Moretti are conspicuous in many ways. Trained in Marxism and Russian formalism, he participated in the construction of the New Left in England. Also, he interestingly interpreted the socialization of the individual through the genre of bildungsroman. Then, he shifted his research interest to the notion of world literature, and to explore its global scale, he developed his own quantitative approach combined with advanced computer technology in digital humanities. His recent publication reveals that Moretti conducted a social critique of the European bourgeois culture with his new quantitative method. His macroscopic view of literature and use of cutting-edge technology in his research inspire historians of Korean literature located in the so-called periphery of world literature. Therefore, the purpose of this study is to examine the idea of world literature outlined by Franco Moretti by reviewing his method called "distant reading" and examples of such an approach. His distant reading is to construct a macroscopic archive through inclusion of forgotten works from literary history and to analyze morphological patterns that frequently appear in the archive. His book entitled Graphs, Maps, Trees is a collection of examples of which he applied distant reading. By delving into such cases, I will raise questions about Moretti's macroscopic perspective of world literature in conjunction with Korean literature. As located at the periphery of global circulation of literary knowledge, Korea appropriated Western genres, established its literary institutions, and developed book markets through modern newspapers and magazines. This experience of furthering modern literature through periodicals would provide another view to revisit Moretti's world literature.

A Study on the Design of Data Collection System for Growing Environment of Crops (작물 근권부 생장 환경 Data 수집 시스템 설계에 관한 연구)

  • Lee, Ki-Young;Jeong, Jin-Hyoung;Kim, Su-Hwan;Lim, Chang-Mok;Lee, Sang-Sik
    • The Journal of Korea Institute of Information, Electronics, and Communication Technology
    • /
    • v.11 no.6
    • /
    • pp.764-771
    • /
    • 2018
  • Domestic and foreign agricultural environments nowadays are undergoing various changes such as aging of agricultural population, increase of earned population, rapid climate change, diversification of agricultural product distribution structure, depletion of water resources and limited cultivation area. In order to respond to various environmental changes in recent agriculture, practical use of Smart Greenhouse to easily record, store and manage crop production information such as crop growing information, growth environment and agriculture work log, Interest is growing. In this paper, we propose a system that collects the situation information necessary for growth such as temperature, humidity, solar radiation, CO2 concentration, and monitor the collected data, which can be measured in the rhizosphere of the crop. We have developed a system that collects data such as temperature, humidity, radiation, and growth environment data, which are measured by data obtained from the rhizosphere measuring section of a growing crop and measured by a sensor, and transmitted to a wireless communication gateway of 400 MHz. We developed the integrated SW that can monitor the rhythm environment data and visualize the data by using cloud based data. We can monitor by graph format and data format for visualization of data. The existing smart farm managed crops and facilities using only the data within the farm, and this study suggested the most efficient growth environment by collecting and analyzing the weather and growth environment of the farms nationwide.

Propylene/Nitrogen Separation Membranes Based on Amphiphilic Copolymer Grafted from Poly(1-trimethylsilyl-1-propyne) (양친성 고분자가 그래프팅된 Poly(1-trimethylsilyl-1-propyne) 기반의 프로필렌/질소 분리막)

  • Park, Cheol Hun;Lee, Jae Hun;Park, Min Su;Kim, Jong Hak
    • Membrane Journal
    • /
    • v.29 no.2
    • /
    • pp.88-95
    • /
    • 2019
  • Hydrocarbons containing carbon double bonds are generally called olefins and it is extensively used in petro-chemical industry as essential base material. Especially, olefins are essential in polymer synthesis and thus the effective separation and purification of olefins from gas mixture are very important and it gives significant positive effect on the future industrial development. In this study, we fabricated polymeric composite membrane based on poly(1-trimethylsilyl-1-propyne) (PTMSP) for propylene/nitrogen separation and enhancement of its separation performance by grafting amphiphilic copolymer. Furthermore, to accelerate facilitated transport for propylene molecules, Ag salt ($AgBF_4$) and ionic liquid ($EMIM-BF_4$) was incorporated to polymer composite membranes. The neat PTMSP membrane exhibited extremely high gas permeance and low gas selectivity due to its high free volume. To address this issue, PTMSP was grafted with poly(oxyethylene glycol methacrylate) (POEM) and poly(ethylene glycol) behenyl ether methacrylate (PEGBEM). Additionally, the additives such as $AgBF_4$ and $EMIM-BF_4$ further increased the propylene permeance, resulting in increment of propylene/nitrogen selectivity.

A Numerical Study on the Selection of Main Specification of the 18.5ft Bass Fishing Boat (18.5ft급 경기용 배스보트의 주요제원 선정에 관한 수치해석 연구)

  • Lim, Jun-Taek;Seo, Kwang-Cheol;Park, Geun-Hong;Kim, Sang-Won
    • Journal of the Korean Society of Marine Environment & Safety
    • /
    • v.24 no.7
    • /
    • pp.945-952
    • /
    • 2018
  • Recently, bass fishing has become a marine leisure sport in Korea. There are 4 major fishing associations in Korea, and each association holds 10-15 tournaments each year. However, supply of 17 ft bass boats, which are preferred in leagues, depends 100 % on imports. In this study, we have derived the main specifications to develop the initial hull forms of a 18.5ft bass boat through statistical analysis based on mothership data. In addition, CFD numerical analysis was carried out according to deadrise angle and longitudinal center of gravity, which strongly influenced the resistance and planing performance. For numerical analysis, design speed was set to $Fn=3.284 (Re=9.858{\times}10^7)$, the deadrise angle was set from 12 to $20^{\circ}$, and the longitudinal center of gravity was set in the range of 0 to $8%L_{wL}$ from the center of buoyancy to the stern. Based on the numerical results, we first set the range of these factors by resistance performance and immersion keel length. Furthermore, using a correlation graph of Savitsky's Drag-Lift ratio, we derived the deadrise angle ($14-16^{\circ}$) and longitudinal center of gravity ($4-6%L_{wL}$).

Study of the Heeling Angle Prediction by using Simulation Data (시뮬레이션 데이터를 이용한 횡경사 각도 예측 방법 연구)

  • Youn, Dong-Hyup;Park, Chung-Hwan;Yim, Nam-Gyun
    • Journal of Navigation and Port Research
    • /
    • v.43 no.4
    • /
    • pp.231-236
    • /
    • 2019
  • As ships become bigger, faster, and diverse, transportation has increased the usage of marine vehicles. However, ship accidents are increasing. Ship accidents cause loss of life and property as well as environmental disasters. The occurrence of ship accidents causes enormous economic and environmental impacts. Notably, in the case of passenger ships, methods for preventing ship accidents are being discussed to avoid losing numerous human lives. The purpose of this study is to provide essential data for evacuation before reaching the dangerous time by predicting the time to reach the risk of capsizing based on the heeling angle of the passenger ship. Based on sinking accidents between 2012 and 2016, we set up specific scenarios and simulated the PRR1 data using commercial software MOSES V20. In the case of the linear equation, the simulation results showed a low error rate because the simulation data showed the linear graph. In the case of the quadratic equation, the error rate was low at the beginning but showed a high error rate at the subsequent angle.

Application of Lee Silverman Voice Treatment-BIG(LSVT-BIG) Intervention to Improve Motor Functions and Quality of Life in People With Parkinson Disease (파킨슨병 환자에게 Lee Silverman Voice Treatment-BIG(LSVT-BIG) 프로그램의 적용이 운동기능과 삶의 질에 미치는 효과)

  • Park, Kang-Hyun;Kim, Jae-Hwan;Jang, Jong-Sik
    • Therapeutic Science for Rehabilitation
    • /
    • v.8 no.1
    • /
    • pp.73-84
    • /
    • 2019
  • Objective: The purpose of this study is to compare the effect of Lee Silverman Voice Treatment-BIG(LSVT-BIG) intervention which consisted of standardized exercise programs and occupation-based activities for people with Parkinson Disease(PD) on motor functions and quality of life Methods: This study applied a one group pretest-posttest design. The experiment was divided into two parts: pre intervention and post intervention period. Before and after LSVT-BIG intervention, Unified Parkinson's Disease Rating Scale(UPDRS), Time up and go(TUG), Parkinson's Disease Questionnaire-39(PDQ-39) were used to measure the participants' motor functions and quality of life. Based on the LSVT-BIG protocol, three participants received 16 one-hour sessions over 4 weeks by a certified occupational therapist. The results were analyzed by using SPSS. Results: There were improvements in UPDRS and TUG. Additionally, PDQ-39 scores decreased in all participants, which means that their quality of life was improved. Conclusions: The study demonstrated positive effects of LSVT-BIG intervention on motor functions and quality of life of patients with PD.

The Improvement of maintainability evaluation method at system level using system component information and fuzzy technique (시스템의 구성품 정보와 퍼지 기법을 활용한 시스템 수준 정비도 평가 방법의 개선)

  • Yoo, Yeon-Yong;Lee, Jae-Chon
    • Journal of the Korea Academia-Industrial cooperation Society
    • /
    • v.20 no.3
    • /
    • pp.100-109
    • /
    • 2019
  • Maintainability indicates the extent to which maintenance can be done easily and quickly. The consideration of maintainability is crucial to reduce the operation and support costs of weapon systems, but if the maintainability is evaluated after the prototype production is done and necessitates design changes, it may increase the cost and delay the schedule. The evaluation should verify whether maintenance work can be performed, and support the designers in developing a design to improve maintainability. In previous studies, the maintainability index was calculated using the graph theory at the early design phase, but evaluation accuracy appeared to be limited. Analyzing the methods of evaluating the maintainability using fuzzy logic and 3D modeling indicate that the design of a system with good maintainability should be done in an integrated manner during the whole system life cycle. This paper proposes a method to evaluate maintainability using SysML-based modeling and simulation technique and fuzzy logic. The physical design structure with maintainability attributes was modeled using SysML 'bdd' diagram, and the maintainability was represented by an AHP matrix for maintainability attributes. We then calculated the maintainability using AHP-based weighting calculation and fuzzy logic through the use of SysML 'par' diagram that incorporated MATLAB. The proposed maintainability model can be managed efficiently and consistently, and the state of system design and maintainability can be analyzed quantitatively, thereby improving design by early identifying the items with low maintainability.

Feeding Relationship between Co-occurring Silver Croaker (Pennahia argentata) and Japanese Sillago (Sillago japonica) in the Nakdong River Estuary, Korea (낙동강 하구역에 출현하는 보구치(Pennahia argentata)와 청보리멸(Sillago japonica)의 섭식관계)

  • Huh, Sung-Hoi;Choi, Hee Chan;Park, Joo Myun
    • Korean Journal of Ichthyology
    • /
    • v.30 no.4
    • /
    • pp.224-231
    • /
    • 2018
  • Dietary niches can support the coexistence of sympatric species in marine ecosystems, which can lead to the presence of greater abundances of those species. Stomach contents of silver croaker (Pennahia argentata) and Japanese sillago (Sillago japonica) inhabiting the Nakdong River estuary, Korea were analyzed to determine diet compositions and the presence of any size-related and inter-specific feeding relationships. These species were bottom-feeding predators that consumed mainly benthic crustaceans and mollusks, but polychaetes were also important in the S. japonica diets. Non-metric multidimensional scaling (nMDS) ordination and multivariate analyses based on weight contributions of the different prey taxa to stomach contents revealed significant inter-specific dietary differences. Size-related change was also significant for P. argentata diets, but not for S. japonica. Canonical analysis of principal coordinate (CAP) ordination plot further demonstrated that differences in the type and range of prey ingested by the two species contributed such an inter-specific difference in the diet compositions. The results from this study provide clear evidence of niche segregation between co-occurring P. argentata and S. japonica in the Nakdong River estuary, which would reduce the likelihood of inter-specific competition for food resources.

Computation of Maintainability Index Using SysML-Based M&S Technique for Improved Weapon Systems Development (SysML 기반 모델링 및 시뮬레이션 기법을 활용한 무기체계 정비도 지수 산출)

  • Yoo, Yeon-Yong;Lee, Jae-Chon
    • Journal of the Korea Academia-Industrial cooperation Society
    • /
    • v.19 no.11
    • /
    • pp.88-95
    • /
    • 2018
  • Maintainability indicates how easily a system can be restored to the normal state when a system failure occurs. Systems developed to have high maintainability can be competitive due to reduced maintenance time, workforce and resources. Quantification of the maintainability is possible in many ways, but only after prototype production or with historical data. As such, the graph theory and 3D model data have been used, but there are limitations in management efficiency and early use. To solve this problem, we studied the maintainability index of weapon systems using SysML-based modeling and simulation technique. A SysML structure diagram was generated to simultaneously model the system design and maintainability of system components by reflecting the maintainability attributes acquired from the system engineering tool. Then, a SysML parametric diagram was created to quantify the maintainability through simulation linked with MATLAB. As a result, an integrated model to account for system design and maintainability simultaneously has been presented. The model can be used from early design stages to identify components with low maintainability index. The design of such components can be changed to improve maintainability and thus to reduce the risks of cost overruns and time delays due to belated design changes.