• Title/Summary/Keyword: instability analysis

Search Result 1,646, Processing Time 0.032 seconds

Factors influencing quality of life for individuals and Korean society: Indigenous psychological analysis across different generations (한국 사회와 개인 삶의 질 인식에 대한 토착심리 탐구: 삶의 질을 높이는 요소와 낮추는 요소에 대한 세대별 지각을 중심으로)

  • Youngshin Park;Uichol Kim
    • Korean Journal of Culture and Social Issue
    • /
    • v.12 no.1
    • /
    • pp.161-195
    • /
    • 2006
  • The purpose of this study is to examine factors influencing quality of life for individuals in the family, school or workplace, leisure settings, and Korean society using the indigenous psychological analysis. A total of 3,406 participants, consisting of 1,331 elementary, middle, high school students and 2,075 parents and teacher, completed an open-ended questionnaire developed by Kim and Park (2004b). The respondents reported the factors that influence quality of life in Korean society as follows: Economic condition, collective effort, leisure and cultural life, harmonious interpersonal relationships, effective government policy, and educational attainment. The factors that reduce quality of life in Korean society are as follows: Economic uncertainty, political instability, lack of citizenry, ingroup favoritism, corruption, lack of facilities for leisure and social life, and overemphasis on educational achievement. Second, the factors that influence quality of life in the family are as follows: Harmonious family relations and financial security. For students relationship with friends and academic achievement are reported as important factors influencing quality of life at school. For adults, harmonious interpersonal relationship, financial factors and occupational achievement are reported as important factors influencing quality of life at the workplace. For leisure and social leisure life, financial security, leisure time and interpersonal relationships are reported as important factors influencing quality of life. Third, as for generational differences, students reported political instability and adults reported economic uncertainty as the most important factor reducing quality of life in Korean society. For family life, students reported conflicts among family members and adults reported financial constraints as the most important factor reducing quality of life. For leisure and social life, students reported lack of leisure time and adults reported financial constraints as the most important factor reducing quality of life. Fourth, for students the following characteristics were associated with higher quality of life: Higher socio-economic status of the family, younger, and higher academic achievement. For adults, the following characteristics were associated with higher quality of life: Higher socio-economic status of the family and greater achievement their social life. Implications of these results on the quality of life in Korea, focusing on human relationship, financial factors, self-regulation and educational achievement are discussed.

Analysis for Atomic Structural Deterioration and Electrochemical Properties of Li-rich Cathode Materials for Lithium Ion Batteries (리튬이차전지용 리튬과잉계 양극 산화물의 충방전 과정 중 원자 구조 열화 과정과 전기화학 특성에 대한 분석)

  • Park, Seohyeon;Oh, Pilgun
    • Applied Chemistry for Engineering
    • /
    • v.31 no.1
    • /
    • pp.97-102
    • /
    • 2020
  • Recently, various degradation mechanisms of lithium secondary battery cathode materials have been revealed. As a result, many studies on overcoming the limitation of cathode materials and realizing new electrochemical properties by controlling the degradation mechanism have been reported. Li-rich layered oxide is one of the most promising cathode materials due to its high reversible capacity. However, the utilization of Li-rich layered oxide has been restricted, because it undergoes a unique atomic structure change during the cycle, in turn resulting in unwanted electrochemical degradations. To understand an atomic structure deterioration mechanism and suggest a research direction of Li-rich layered oxide, we deeply evaluated the atomic structure of 0.4Li2MnO3_0.6LiNi1/3Co1/3Mn1/3O2 Li-rich layered oxide during electrochemical cycles, by using an atomic-resolution analysis tool. During a charge process, Li-rich materials undergo a cation migration of transition metal ions from transition metal slab to lithium slab due to the structural instability from lithium vacancies. As a result, the partial structural degradation leads to discharge voltage drop, which is the biggest drawback of Li-rich materials.

Evaluation of Dynamic Stability of Precast Floating Slab Track with Vehicle-Track Interaction Analysis (차량-궤도 상호작용 해석을 통한 사전 제작형 플로팅 슬래브 궤도의 동적 안정성 검토)

  • Jang, Dongdoo;Kim, Jin-Ho;Kwon, Se-Gon
    • Journal of the Korea Academia-Industrial cooperation Society
    • /
    • v.18 no.3
    • /
    • pp.562-568
    • /
    • 2017
  • A precast floating slab track with a 5m slab panel and installed with isolators is proposed to solve the noise and vibration problem at existing elevated railway stations. Thus, the construction can be carried out rapidly without interrupting the train operation. However, dynamic instability problems may be caused by repeated discontinuities in track due to the short slab panel length and excessive rail displacement due to the inherent operation mechanism of a floating system in reducing the vibration. Furthermore, the difference of the supporting stiffness at the transition between the floating track and ballast track may raise problems. In this study, the assessment factors to evaluate the dynamic stability of the precast floating slab track are presented and assessed with the vehicle-track interaction analysis. Through the analysis, all values relevant to the stability at the floating track section are found to be acceptable, and the slab panels at the transition section are designed to satisfy the stability.

On Analyzing the "Hell-Chosun" Phenomenon in Contemporary South Korea Through a Textual Analysis of Media Representation ('헬조선 현상'의 특징과 함의를 분석하기 보수언론과 진보언론 간의 재현작용에 대한 텍스트 분석을 중심으로)

  • Kim, Aerin;Im, Hye Bin;Chang, Hansl;Park, Juhwa;Ki, Seungyeon;Jeong, Yoon Jung;Kim, Sujin;Shin, Juyeong;Lee, Keehyeung
    • Korean journal of communication and information
    • /
    • v.80
    • /
    • pp.40-114
    • /
    • 2016
  • This work critically explores the so-called "Hell-Chosun" phenomenon which has gained much attention and responses in contemporary South Korea. The younger generation came to coin and utilize this new linguistic expression as well as poignant parody as a way of releasing their anger, cynicism, and frustration in the context of the omnipresent fierce competitions, deepening social instability, and job-related shrinking possibilities. The 'Hell-Chosun' phenomenon can be considered as a much complicated manifestation of the structures of feeling for the part of many younger generation South Koreans. This paper especially examines the varying representation of this phenomenon by established dailies through an in-depth textual analysis of newspaper articles, opinion pieces and reviews, as well as special issues. In doing so, this work examines the multiple implications of this particular socio-cultural phenomenon in a detailed and critical fashion.

  • PDF

Tunnel Stability Assessment Considering Rock Damage from Blasting Near to Excavation Line (굴착선 주변공 발파의 암반손상을 고려한 터널 안정성 검토)

  • 이인모;윤현진;이형주;이상돈;박봉기
    • Journal of the Korean Geotechnical Society
    • /
    • v.19 no.4
    • /
    • pp.167-178
    • /
    • 2003
  • Damage and overbreak of the remaining rock induced by blasting can not be avoided during tunnel construction which may result in either short-term or long-term tunnel instability. Therefore, in this paper, a methodology to take into account the effect of blast-induced damage in tunnel stability assessment is proposed. Dynamic numerical analysis was executed to evaluate damage and overbreak of the remaining rock for the most common blasting pattern in road tunnel. Rock damage was quantified by utilizing the damage variable factor which is adopted proposed in continuum damage mechanics. The damaged rock stiffness and the damaged failure criteria are used to consider the effect of rock damage in tunnel stability analysis. The damaged geological strength index of the damaged rock was newly proposed from the relationship between deformation modulus and geological strength index. Also the Hoek-Brown failure criteria of the damaged rock was obtained using the damaged geological strength index. Analysing the tunnel stability with the consideration of the blast-induced damage of remaining rock, it was found that the extend of plastic zone and deformation increased compared to the undamaged rock. Therefore the short-term or long-term tunnel stability will be threatened when the rock damage from blasting is ignored in the tunnel stability analysis.

Comparison Among the Four Examination Methods for Dry Eye (OQAS test, TBUT, Schirmer Test, McMonnies test) (4가지 건성안 분석방법(OQAS test, TBUT, Schirmer test, McMonnies test)의 비교)

  • Park, Chang Won;Kim, Hyojin
    • Journal of Korean Ophthalmic Optics Society
    • /
    • v.20 no.4
    • /
    • pp.519-526
    • /
    • 2015
  • Purpose: To evaluate the changes of OSI value according to tear-film instability measured serially by OQAS(Optical Quality Analysis System, Visiometrics, Spain) every seconds. The presented study analyzed the relationship of the OQAS parameter with the results of the tear-film break-up time, Schirmer test, and the McMonies score. Methods: 147 eyes of 82 subjects were randomly selected from university students (age: $21.51{\pm}3.97$, male 45, female 37). Subjects were measured tear-film break-up time, Schirmer test, McMonies score and once every second for 15 seconds after blinking by continuous measurements from OQAS system. Results: The normal eye groups presented OSI values of $2.13{\pm}1.16$ while the dry eye groups had OSI values of $3.76{\pm}1.42$. Therefore, a significant difference between the normal eye group and dry eye group was discovered (p<0.05). In addition, the OSI value of all subjects increased over time. The OSI value, which was measured every second after blinking occurred, significantly increased between 6 seconds and 7 seconds after the start of the measurement (p<0.05). OSI cut off of 30% (sec.) showed a greater correlation; TBUT (r = 0.855, p = 0.000), McMonies test (r = -0.351, p = 0.003), Schirmer (r = 0.316, p = 0.012). Conclusions: Continuous measurement of OQAS showed a high correlation with the value of the existing dry eye tests. Therefore, Analysis of OSI values by utilization of OQAS could be useful in objectively evaluation of tear film in patients.

Seismic Evaluation of Steel Moment Frame Buildings based on Different Response Modification Factors and Fundamental Periods (반응수정계수와 주기의 영향에 대한 철골모멘트저항골조 건물의 내진성능평가)

  • Shin, Ji-Wook;Lee, Ki-Hak;Lee, Do-Hyung
    • Journal of the Earthquake Engineering Society of Korea
    • /
    • v.12 no.5
    • /
    • pp.47-56
    • /
    • 2008
  • This study was performed to evaluate the effect of Response modification factors (R-factor) in 3-, 9- and 20- story steel Moment Resisting Frame (MRF) buildings. Each structure was designed using a R-factor of 8, as tabulated in the 2000 International Building Code provision (IBC 2000) and Korea Building Code (KBC) 2008. In order to evaluate the maximum and minimum performance expected for such structures, an upper bound and lower bound design were adopted for each model. Next, each analytical model was designed using different R-factors (8, 9, 10, 11, 12) and four different structural periods with the original fundamental period. For a detailed case study, a total of 150 analytical models were subjected to 20 ground motions representing a hazard level with a 2% probability of being exceeded in 50 years. In order to evaluate the performance of the structures, static push-over and non-linear time history analysis (NTHA) were performed, and displacement ductility demand was investigated to consider the ductility capacity of the structures. The results show that the dynamic behaviors for the 3- and 9-story buildings are relatively stable and conservative, while the 20-story buildings show a large displacement ductility demand due to dynamic instability factors. (e.g. P-delta effect and high mode effect)

Analytical Research on Knowledge Production, Knowledge Structure, and Networking in Affective Computing (Affective Computing 분야의 지식생산, 지식구조와 네트워킹에 관한 분석 연구)

  • Oh, Jee-Sun;Back, Dan-Bee;Lee, Duk-Hee
    • Science of Emotion and Sensibility
    • /
    • v.23 no.4
    • /
    • pp.61-72
    • /
    • 2020
  • Social problems, such as economic instability, aging population, heightened competition, and changes in personal values, might become more serious in the near future. Affective computing has received much attention in the scholarly community as a possible solution to potential social problems. Accordingly, we examined domestic and global knowledge structure, major keywords, current research status, international research collaboration, and network for each major keyword, focusing on keywords related to affective computing. We searched for articles on a specialized academic database (Scopus) using major keywords and carried out bibliometric and network analyses. We found that China and the United States (U.S.) have been active in producing knowledge on affective computing, whereas South Korea lags well behind at around 10%. Major keywords surrounding affective computing include computing, processing, affective analysis, research, user modeling categorizing recognitions, and psychological analysis. In terms of international research collaboration structure, China and the U.S. form the largest cluster, whereas other countries like the United Kingdom, Germany, Switzerland, Spain, and Canada have been strong collaborators as well. Contrastingly, South Korea's research has not been diverse and has not been very successful in producing research outcomes. For the advancement of affective computing research in South Korea, the present study suggests strengthening international collaboration with major countries, including the U.S. and China and diversifying its research partners.

Trend Analysis of Corona Virus(COVID-19) based on Social Media (소셜미디어에 나타난 코로나 바이러스(COVID-19) 인식 분석)

  • Yoon, Sanghoo;Jung, Sangyun;Kim, Young A
    • Journal of the Korea Academia-Industrial cooperation Society
    • /
    • v.22 no.5
    • /
    • pp.317-324
    • /
    • 2021
  • This study deals with keywords from social media on domestic portal sites related to COVID-19, which is spreading widely. The data were collected between January 20 and August 15, 2020, and were divided into three stages. The precursor period is before COVID-19 started spreading widely between January 20 and February 17, the serious period denotes the spread in Daegu between February 18 and April 20, and the stable period is the decrease in numbers of confirmed infections up to August 15. The top 50 words were extracted and clustered based on TF-IDF. As a result of the analysis, the precursor period keywords corresponded to congestion of the Situation. The frequent keywords in the serious period were Nation and Infection Route, along with instability surrounding the Treatment of COVID-19. The most common keywords in all periods were infection, mask, person, occurrence, confirmation, and information. People's emotions are becoming more positive as time goes by. Cafes and blogs share text containing writers' thoughts and subjectivity via the internet, so they are the main information-sharing spaces in the non-face-to-face era caused by COVID-19. However, since selectivity and randomness in information delivery exists, a critical view of the information produced on social media is necessary.

Analysis of the Relationship between Macpa Stress Index and Korean Job Stress Level - Focusing on Subway Construction Workers (맥파 스트레스와 한국인 직무스트레스의 상관관계 분석 - 도시철도 건설종사자를 대상으로)

  • Chae, Joung Sik;Lee, Yu Jeong;Chang, Seong Rok
    • Journal of the Korean Society of Safety
    • /
    • v.37 no.1
    • /
    • pp.64-69
    • /
    • 2022
  • The study measured a subway construction worker's Macpa stress by Heart Rate Variability measuring instrument and conducted a survey of Korean job stress from subway construction workers. Also, the study analyzed the relationship between Macpa stress index and Korean job stress result and suggested managing stress method for each item. According to National Statistical Office data, the first line subway in Seoul was started to open in 1974. The extended total length is 996 kilometers until 2019. Many aged workers are currently working at subway construction sites due to the avoidance of young workers since the past until now. It means that the elderly has a substantial portion among subway construction workers. The productivity has been adversely affected by health problems due to the aging of workers, job stress due to heavy work, and personal health problems. So, the regulation and policies on job stress health management are being strengthened. The data were measured Macpa stress by machine measuring heart rate variability and conducted Korean job stress survey(shortened) from Sa-sang to Ha-dan line Busan subway construction workers for analyzing the relationship. Independent variable were age, job duration, job position, employment type, working type in this study. Macpa's dependent variable was stress index and Korean job stress survey(shortened)'s dependent variables were job requirements, job autonomy, relationship conflict, job instability, organizational structure, inappropriate compensation, working place culture, and total score. SPSS 12.0 K Statistics Program was used for statistical analysis. Kruskal-wallis test, a nonparametric statistical analysis, was used because the data are difficult to be assumed as normal distribution. As a result, the paper indicated the significant correlation between Macpa stress index and Korean job stress(short version). The elderly workers presented higher Macpa index and higher job stress due to aging and heavy-duty work. The majority workers were daily workers who had unstable working condition and uncertainty about the future. The study suggested a manual that could reduce job stress for subway construction workers and future study deriving management tool through analyzing job stress factor is necessary.