• Title/Summary/Keyword: dynamic characteristics

Search Result 8,619, Processing Time 0.047 seconds

Electrochemical Characteristics of Cu3Si as Negative Electrode for Lithium Secondary Batteries at Elevated Temperatures (리튬 이차전지 음극용 Cu3Si의 고온에서의 전기화학적 특성)

  • Kwon, Ji-Y.;Ryu, Ji-Heon;Kim, Jun-Ho;Chae, Oh-B.;Oh, Seung-M.
    • Journal of the Korean Electrochemical Society
    • /
    • v.13 no.2
    • /
    • pp.116-122
    • /
    • 2010
  • A $Cu_3Si$ film electrode is obtained by Si deposition on a Cu foil using DC magnetron sputtering, which is followed by annealing at $800^{\circ}C$ for 10 h. The Si component in $Cu_3Si$ is inactive for lithiation at ambient temperature. The linear sweep thermammetry (LSTA) and galvano-static charge/discharge cycling, however, consistently illustrate that $Cu_3Si$ becomes active for the conversion-type lithiation reaction at elevated temperatures (> $85^{\circ}C$). The $Cu_3Si$ electrode that is short-circuited with Li metal for one week is converted to a mixture of $Li_{21}Si_5$ and metallic Cu, implying that the Li-Si alloy phase generated at 0.0 V (vs. Li/$Li^+$) at the quasi-equilibrium condition is the most Li-rich $Li_{21}Si_5$. However, the lithiation is not extended to this phase in the constant-current charging (transient or dynamic condition). Upon de-lithiation, the metallic Cu and Si react to be restored back to $Cu_3Si$. The $Cu_3Si$ electrode shows a better cycle performance than an amorphous Si electrode at $120^{\circ}C$, which can be ascribed to the favorable roles provided by the Cu component in $Cu_3Si$. The inactive element (Cu) plays as a buffer against the volume change of Si component, which can minimize the electrode failure by suppressing the detachment of Si from the Cu substrate.

A Study on the Behaviour of Prebored and Precast Steel Pipe Piles from Full-Scale Field Tests and Class-A and C1 Type Numerical Analyses (현장시험과 Class-A 및 C1 type 수치해석을 통한 강관매입말뚝의 거동에 대한 연구)

  • Kim, Sung-Hee;Jung, Gyoung-Ja;Jeong, Sang-Seom;Jeon, Young-Jin;Kim, Jeong-Sub;Lee, Cheol-Ju
    • Journal of the Korean GEO-environmental Society
    • /
    • v.18 no.7
    • /
    • pp.37-47
    • /
    • 2017
  • In this study, a series of full-scale field tests on prebored and precast steel pipe piles and the corresponding numerical analysis have been conducted in order to study the characteristics of pile load-settlement relations and shear stress transfer at the pile-soil interface. Dynamic pile load tests (EOID and restrike) have been performed on the piles and the estimated design pile loads from EOID and restrike tests were analysed. Class-A type numerical analyses conducted prior to the pile loading tests were 56~105%, 65~121% and 38~142% respectively of those obtained from static load tests. In addition, design loads estimated from the restrike tests indicate increases of 12~60% compared to those estimated in the EOID tests. The EOID tests show large end bearing capacity while the restrike tests demonstrate increased skin friction. When impact energy is insufficient during the restrike tests, the end bearing capacity may be underestimated. It has been found that total pile capacity would be reasonably estimated if skin friction from the restrike tests and end bearing capacity from the EOID are combined. The load-settlement relation measured from the static pile load tests and estimated from the numerical modelling is in general agreement until yielding occurs, after which results from the numerical analyses substantially deviated away from those obtained from the static load tests. The measured pile behaviour from the static load tests shows somewhat similar behaviour of perfectly-elastic plastic materials after yielding with a small increase in the pile load, while the numerical analyses demonstrates a gradual increase in the pile load associated with strain hardening approaching ultimate pile load. It has been discussed that the load-settlement relation mainly depends upon the stiffness of the ground, whilst the shear transfer mechanism depends on shear strength parameters.

A Study of 'Families' as presented during the Technology-Home Economics Subject in Middle School: Focusing on the 'The Changing Family' of the 2007 Revised Curriculum (중학교 기술.가정 교과서에 나타난 '가족'에 관한 연구 - 2007 개정 교육과정의 '변화하는 가족' 단원을 중심으로 -)

  • Jun, Mi-Kyung
    • Journal of Korean Home Economics Education Association
    • /
    • v.24 no.2
    • /
    • pp.29-49
    • /
    • 2012
  • The purpose of this study is to look at families as presented on the technology-home economics subject of middle school. To do this, I analyzed the 2007 revised curriculum of the technology-home economics subject, 'Changing Families,' in 11 technology-home economics textbooks (8th grade). The findings are as follows. First, family-related chapters are expanded compared with the previous curriculum in the 2007 revised curriculum. In addition, the new version emphasizes understanding and acceptance of change in families to improve the family life of adolescents. Second, in the 11 types of technology-home economics textbooks, the focusing was on the meaning of the family, the family structure, the function of the family, family roles and family values. There were also no major differences in the aspect of development. Third, in the technology-home economics textbooks, the family was defined as the 'basic group of society', 'a group composed by blood relationships, marriage and adoption', 'an affective group' and 'cohabiting group'. At the same time, there were many cases in which the description of the family was overly romanticized. Such a description of the family does not match the individual family experience of an adolescent. Fourth, all of textbooks dealt with the diversity of the family structure, such as single-parent families, remarriages families, and multi-cultural families. However, the structural characteristics and problems with these types of families are excessively emphasized, which can result in students having stereotypical images of specific family types. Fifth, the explanation of the function of the family was similar among textbooks. The importance of intergenerational cooperation and gender equality was also emphasized. However, such a concept is not considered as proper in a modern society. Thus, the description of a family based on the nuclear family should be sublated. In addition, the explanation of families overall should be developed in such a way that adolescents can interpret their own family experience rather than as an enlightening declaration of the family which disregards the dynamic relationships individual families actually experience.

  • PDF

The Impact of monsoon Rainfall (Changma) on the Changes of Water Quality in the Lower Nakdong River (Mulgeum) (장마기의 강우가 낙동강 하류 (물금) 수질에 미치는 영향)

  • Park, Sung-Bae;Lee, Sang-Kyun;Chang, Kwang-Hyeon;Jeong, Kwang-Suek;Joo, Gea-Jae
    • Korean Journal of Ecology and Environment
    • /
    • v.35 no.3 s.99
    • /
    • pp.160-171
    • /
    • 2002
  • The impact of summer monsoon on water quality of the lower Nakdong River was evaluated during the summer (June-August) in 1997. Several limnological variables were measured in the interval of $1{\sim}3$ day using an automatic monitoring system (Hydrolab $Recorder^{TM}$) to detect water quality changes caused by rainfall on onehour basis. During the monsoon period (from late June to mid July), 5 times of major rainfall events of >50 mm were recorded in the river basin. Dynamic changes of water quality were observed during the monsoon, and the first rainfall event (June$25{\sim}27$) had a significant influence on the water quality at the lower part of the river. All Parameters were largely changed due to the first rain event, and the changed level was maintained until the end of monsoon period. Nutrient concentrations and turbidity increased and values of the other parameters were declined as a result of water dilution. This rainfall event, Changma, is a meteorological phenomenon caused by the East-Asian monsoon climate. The magnitude and frequency of the rainfall during the early monsoon play an important role in change of water quality and ecosystem characteristics of large river systems.

Current Development of Company Law in the European Union (유럽주식회사법의 최근 동향에 관한 연구)

  • Choi, Yo-Sop
    • Journal of Legislation Research
    • /
    • no.41
    • /
    • pp.229-260
    • /
    • 2011
  • European Union (EU) law has been a complex but at the same time fascinating subject of study due to its dynamic evolution. In particular, the Lisbon Treaty which entered into force in December 2009 represents the culmination of a decade of attempts at Treaty reform and harmonisation in diverse sectors. Amongst the EU private law fields, company law harmonisation has been one of the hotly debated issues with regards to the freedom of establishment in the internal market. Due to the significant differences between national provisions on company law, it seemed somewhat difficult to harmonise company law. However, Council Regulation 2157/2001 was legislated in 2001 and now provides the basis for the Statute for a European Company (or Societas Europaea: SE). The Statute is also supplemented by the Council Directive 2001/86 on the involvement of employees. The SE Statute is a legal measure in order to contribute to the internal market, and provides a choice for companies that wish to merge, create a joint subsidiary or convert a subsidiary into an SE. Through this option, the SE became a corporate form which is only available to existing companies incorporated in different Member States in the EU. The important question on the meaning of the SE Statute is whether the distinctive characteristics of the SE make it an attractive option to ensure significant numbers of SE registration. In fact, the outcome that has been made through the SE Statute is an example of regulatory competition. The traditional regulatory competition in the freedom of establishment has been the one between national statutes between Member States. However, this time is not a competition between Member States, which means that the Union has joined the area in competition between legal orders and is now in competition with the systems of company law of the Member States.Key Words : European Union, EU Company Law, Societas Europaea, SE Statute, One-tier System, Two-tier System, Race to the Bottom A quite number of scholars expect that the number of SE will increase significantly. Of course, there is no evidence of regulatory competition that Korea faces currently. However, because of the increasing volume of international trade and expansion of regional economic bloc, it is necessary to consider the example of development of EU company law. Addition to the existing SE Statute, the EU Commission has also proposed a new corporate form, Societas Private Europaea (private limited liable company). All of this development in European company law will help firms make their best choice for company establishment. The Delaware-style development in the EU will foster the race to the bottom, thereby improving the contents of company law. To conclude, the study on the development of European company law becomes important to understand the evolution of company law and harmonisation efforts in the EU.

Discourse Analysis of Business Chinese and the Comparison of Negotiation Culture between Korea and China - Focused on Business Emails Related to 'Napkin Holder' Imports - (무역 중국어 담화 고찰과 한중 협상문화 비교 - '냅킨꽂이' 수입 관련 비즈니스 이메일을 중심으로 -)

  • Choi, Tae-Hoon
    • Cross-Cultural Studies
    • /
    • v.50
    • /
    • pp.103-130
    • /
    • 2018
  • This research aims to explore the associated linguistic features and functions of Chinese as used for business trading purposes, and which is based on a discourse analysis through a case in which a Korean buyer and a Chinese supplier have exchanged Internet based e-mails. The research questions include first, the linguistic functions and characteristics of Chinese shown as identified in this trade case through e-mails, second, the use of Chinese trade specific terms, and third, the apparent and dynamic negotiation strategies that are identified as followed by the cultural value systems which are used for resolving interest conflicts and issues between the buyer and supplier in the course of negotiating business contracts between two parties. The participants of this research pertain to a Korean buyer, James and a Chinese supplier, Sonya. The associated data consists of 74 e-mails exchanged between the two parties, initiated in an effort to begin and complete a trade item, in this case namely the product of napkin holders. The research for the study is based on the discourse analysis and empirically analyses models of Chinese linguistic functions and features. The findings are the following. First, as identified, the specific Chinese functions used and sequenced in this trade case are of a procedure, request, informing, negotiation and persuasion. Second, the essential trade terms used in this business interaction involve the relevant issues of 1) ordering and price negotiating, 2) marking the origin of the products, 3) the arrangement of the product examination and customs declaration for the anticipated import items, 4) preparation of the necessary legal documents, and 5) the package and transport of the product in the final instance. Third, the impact of the similarities and differences in the cultural value systems between Korea and China on the negotiations and conflict resolution during a negotiated contract between two parties are speculated in terms of the use of culturally based techniques such as face-saving and the utilization of uncertainty-avoiding strategies as meant to prevent misunderstandings from developing between the parties. The concluding part of the study discusses the implications for a practical Chinese language education utilizing the linguistic functions and features of the Chinese culture and language strategies as useful in business associations for trading purposes, and the importance of intercultural communication styles based on similar of different identified cultural values as noted between two parties.

A Study on the Effects of Career Interrupted Women' Personal Attitude and Subjective Norm on Entrepreneurial Intention: Focusing on Moderating Effects on the Entrepreneurial Supporting Policy (경력단절여성의 창업행위에 대한 태도와 주관적 규범이 창업의도에 미치는 영향)

  • Choi, Jinsook;Lee, Namhee;Hwang, Kumju
    • Asia-Pacific Journal of Business Venturing and Entrepreneurship
    • /
    • v.14 no.4
    • /
    • pp.113-132
    • /
    • 2019
  • The degree of females' participation in corporate activity has been recently increased over the world and females' participation in economic activity may be new dynamic fuel for the Korean economy that falls into the vicious cycle of low growth. Start-up, therefore, has increasingly taken attention as an opportunity for females whose careers were interrupted to re-enter the labor market. The need for studies that examine factors influencing the decision of start-up is also increased along with the increase of the ratio of females' start-up. This study aims to verify effects of the women's characteristics(women discrimination, women's role conflict) and the human networks of females whose careers were interrupted, with the intention for entrepreneurial intention, which are mediated by personal attitudes and subjective norm suggested by Ajzen's Theory of Reasoned Action, based on an empirical research. The findings show that the human networks of females have an effect on attitudes toward start-up activity and subjective norm and the woman discrimination influence the personal attitudes. In contrast, the women's role conflict have no effect on both personal attitude toward start-up activity and subjective norm. This can be supposed as an outcome resulted from the subjects' low level of conflict caused by their sex roles, on their age distribution. The relation between subjective norm and entrepreneurial Intention seemed to be moderated by their perceived strong entrepreneurial supporting policy. Their attitudes toward start-up activity were found to have a mediating effect on the relation between the women discrimination, human networks and entrepreneurial Intention, while the subjective norm only mediated the relation between human networks and entrepreneurial Intention. Based on such results, this study attempts to suggest theoretical suggestions and the direction of various entrepreneurial supporting policy for the increase and the growth of start-up of females whose careers were interrupted, in Korea.

The aspect of the revelation of profound secrets of nature in the Poetry of Jo Gyeong[趙璥] and its meaning (조경(趙璥) 시(詩)의 천기유로양상(天機流露樣相)과 그 의미(意味))

  • Ryu, Ho-jin
    • (The)Study of the Eastern Classic
    • /
    • no.49
    • /
    • pp.225-260
    • /
    • 2012
  • The poetry of Haseo Jo Gyeong is first characterized by its fantasy content with mysterious and strange beings such as mountain wizards, gods of flowers, ghosts, Jujos and dragons. Such works imply the huge gap between his political ideal of Neo-Confucianism and the reality of society and are expressions of his resulting sorrow. Of course, he did not just look at reality pessimistically. Like other Neo-Confucianism scholars, he used the symbol of "spring" in his poems, which indicates that he did have optimistic belief in the world in spite of despair. In his poems, the symbol of "spring" implies the political world where the noble man grabbed the power and the sinister groups were extracted or the world where the political ethics of Neo-Confucianism was implemented. His works depicting the essence of natural objects, mountains, and rivers exhibit the characteristics of his poetry more clearly. He described the law of the universe behind natural objects and the vibrant aspects of natural objects by depicting their movements in a clear and sharp manner. Unlike the old Neo-Confucianism scholars that often created poems on the topic of acquirement of natural law and nature, he expanded his poetic world in a direction of revealing the secrets of objects. His works describing the spirit of mountains and rivers are especially noteworthy in that they implied a life attitude of moving forward in an deteriorating world bravely by manifesting strong and dynamic power. Paying attention to the secrets of natural objects, Haseo displayed his life ideal in richer ways by painting the new forms of ume flowers. Unlike the old ume flowers poems in the past, his ume flowers poems present ume flowers as ascetics that obtained truth, men of virtue that inspired contemporary people, or retired gentlemen that revealed the profound secrets of nature. While it is unique that he manifested the forms of ume flowers in ascetics and men of virtue while perceiving the dark reality of society, it is more noteworthy that he described ume flowers as the beings revealing the profound secrets of nature. It was the expression of his yearning for an innocent personality and his fear for losing the personality, clearly depicting a human form of his ego. He created a more human and realistic personality ideal by embracing the contemporary thinking based on the profound secrets of nature in his Dohak poetry[道學詩], which is a significant achievement in that it showed new changes to Dohak poetry in the 18th century.

Application of Greenhouse Climate Management Model for Educational Simulation Design (교육용 시뮬레이션 설계를 위한 온실 환경 제어 모델의 활용)

  • Yoon, Seungri;Kim, Dongpil;Hwang, Inha;Kim, Jin Hyun;Shin, Minju;Bang, Ji Wong;Jeong, Ho Jeong
    • Journal of Bio-Environment Control
    • /
    • v.31 no.4
    • /
    • pp.485-496
    • /
    • 2022
  • Modern agriculture is being transformed into smart agriculture to maximize production efficiency along with changes in the 4th industrial revolution. However, rural areas in Korea are facing challenges of aging, low fertility, and population outflow, making it difficult to transition to smart agriculture. Among ICT technologies, simulation allows users to observe or experience the results of their choices through imitation or reproduction of reality. The combination of the three-dimension (3D) model and the greenhouse simulator enable a 3D experience by virtual greenhouse for fruits and vegetable cultivation. At the same time, it is possible to visualize the greenhouse under various cultivation or climate conditions. The objective of this study is to apply the greenhouse climate management model for simulation development that can visually see the state of the greenhouse environment under various micrometeorological properties. The numerical solution with the mathematical model provided a dynamic change in the greenhouse environment for a particular greenhouse design. Light intensity, crop transpiration, heating load, ventilation rate, the optimal amount of CO2 enrichment, and daily light integral were calculated with the simulation. The results of this study are being built so that users can be linked through a web page, and software will be designed to reflect the characteristics of cladding materials and greenhouses, cultivation types, and the condition of environmental control facilities for customized environmental control. In addition, environmental information obtained from external meteorological data, as well as recommended standards and set points for each growth stage based on experiments and research, will be provided as optimal environmental factors. This simulation can help growers, students, and researchers to understand the ICT technologies and the changes in the greenhouse microclimate according to the growing conditions.

A Study on the Objectives of Cultural Property Education for establish of the U.V.E.C.(Understand, Value, Enjoy, Create) Cultural Property Education (U.V.E.C.(Understand, Value, Enjoy, Create) 문화재교육 정립을 위한 문화재교육 목표 연구)

  • PARK Sanghye
    • Korean Journal of Heritage: History & Science
    • /
    • v.55 no.4
    • /
    • pp.278-294
    • /
    • 2022
  • To date, cultural property education has seen rapid quantitative growth due to national and personal needs. However, qualitative growth is lacking. The objectives of cultural property education have not been established, and therefore, even its identity is not clear. The most pressing issue at present in cultural property education is to first set objectives. This study aimed to analyze the objectives of current cultural property education, identify the problems, and set new objectives to meet significant national and personal needs in terms of education. The problems with the objectives of current cultural property education are that the persons interested in the education do not understand the concept of the education objectives clearly and that the objectives do not contain much actual content of the education. Also, the objectives of the education do not take into account the dynamic competencies and interests of the learners and do not satisfy the changes of the times. To solve these problems, new cultural property education, called 'U.V.E.C.,' was offerred. U.V.E.C. education is aimed at understanding cultural properties, recognizing their value, and enjoying them, and at creating culture. The objectives of U.V.E.C. cultural property education were set such that they can be modified flexibly in a learner-centric way with clear and practical format and contents. Based on this direction, stepwise objectives were set including overall objectives, detailed objectives, and practice objectives, and objective cases of each step were proposed. Considering the generality of the education and the distinct characteristics of the cultural properties, the U.V.E.C. education objectives took into account the diversity of behavioral objectives, clearness in statements, the objectives of problem solving, the initiative of learners and openness for expression outcomes. The U.V.E.C. objectives are clear and specific so that teachers can enhance their pedagogical efficiency and learners are able to develop interesting and diversified competencies. In addition, it is expected that the U.V.E.C. objectives will significantly affect objective setting for education on cultural properties which have not been studied widely. Further systemic and specific studies on the contents and methods of the U.V.E.C. education would help to change the overall education on cultural properties and position the field as a new academic area.