• 제목/요약/키워드: Period Characterized

검색결과 894건 처리시간 0.026초

Bilinear elastodynamical models of cracked concrete beams

  • Pandey, Umesh Kumar;Benipal, Gurmail S.
    • Structural Engineering and Mechanics
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    • 제39권4호
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    • pp.465-498
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    • 2011
  • Concrete structures are generally cracked in flexural tension at working loads. Concrete beams with asymmetric section details and crack patterns exhibit different flexural rigidity depending upon the sense of the applied flexural moment. In this paper, three different models, having the same natural period, of such SDOF bilinear dynamical systems have been proposed. The Model-I and Model-II have constant damping coefficient, but the latter is characterized by two stiffness coefficients depending upon the sense of vibration amplitude. The Model-III, additionally, has two damping coefficients as well. In this paper, the dynamical response of Model-III to sinusoidal loading has been investigated and compared with that of Model-II studied earlier. It has been found that Model-III exhibits regular and irregular sub-harmonics, jump phenomena and strong sensitivity to initial conditions, forcing frequency, system period as well as the sense of peak sinusoidal force. The constant sustained load has been found to affect the natural period of the dynamical system. The predictions of Model-I have been compared with those of the approximate linear model adopted in present practice. The behaviour exhibited by different models of the SDOF cracked elastic concrete structures under working loads and the theoretical and practical implications of the approach followed have been critically evaluated.

청소년 가출에 관한 이론적 고찰 (Literature Review on Adolescent Runaways)

  • 정운숙;박신애
    • 지역사회간호학회지
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    • 제12권1호
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    • pp.105-114
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    • 2001
  • It was orginally thought that runaway adolescents needed to improve their ability to cope with personal problems based on their own understanding of them. As a result we exchanged theoretical background on the matter as follows: 1. Generally, adolescency is a transitional period from childhood to adulthood and characterized by a dramatic conversion period with unique phenomena relative to other periods. Futhermore, it is the key transitional moment in the development of an adult personality. 2, Runaway adolescents are defined as 'adolescents who leave impulsively or intentionally their homes without permission of their parents for at least 24 hours.' 3. The reasons for this behavior are generally regarded as complex, interdependent and dynamic including a cast-away factor. seducing factors, and other action-provoking factors. There is also another view to explain the adolescent run-away as a combination of personal. domestic, academic, peer, or socal factors. 4. We found that adolescent runaways have different attitudes dependent on the reasons and procedures of runaways, lifestyles of adolescents. and results of their runaway experience. In conclusion, runaway adolescents are in a very important period in their development and growth of bodies and minds, but are in a great crisis for various complex reasons. Therefore, we propose that nursing should provide effective nursing interventions to improve the ability of the runaway adolescents address theses problems by themselves.

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Sensing Characteristics of Uncoated Double Cladding Long-period Fiber Grating Based on Mode Transition and Dual-peak Resonance

  • Zhou, Yuan;Gu, Zheng Tian;Ling, Qiang
    • Current Optics and Photonics
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    • 제5권3호
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    • pp.243-249
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    • 2021
  • In this paper, the sensing characteristics of a double cladding fiber (DCF) long-period fiber grating (LPFG) to the surrounding refractive index (SRI) are studied. The outer cladding of the DCF plays the role of the overlay, thus, the mode transition (MT) phenomenon of DCF can be induced by etching the outer cladding radius instead of coating overlays. The response characteristics of the effective refractive index (ERI) of the cladding mode to the outer cladding radius are analyzed. It is found that in the MT range, the change rate of ERIs of cladding modes is relatively larger than that for other ranges. Further, based on the features of the mode transition region (MTR), the phase-matching curve of the 11th cladding mode is investigated, and the response of the DCF-LPFG to the SRI is characterized by the change of wavelength intervals between the dual peaks under different outer cladding radii. The numerical simulation results show that the SRI sensitivity is greatly improved, which is available to 3484.0 nm/RIU with the fitting degree 0.998 in the SRI range of 1.33-1.37. The proposed DCF-LPFG can provide new theoretical support for designing the DCF-LPFG refractive index sensor with excellent performances of sensitivity, linearity and structure.

대두(大豆) 고저단백질(高低蛋白質) 품종(品種)의 성숙중(成熟中) 종실(種實)의 발육(發育)과 단백질(蛋白質) 및 그 구성분(構成分)의 변화(變化) (Changes In Protein and Its Components of High and Low Protein Varieties during Seed Development and Maturation of Soybeans)

  • 이종석
    • 농업과학연구
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    • 제5권2호
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    • pp.56-67
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    • 1978
  • 본(本) 실험(實驗)은 대두(大豆)의 성숙중(成熟中) 종실(種實)의 발육(發育)과 단백질(蛋白質) 및 그 구성분(構成分)의 변화(變化)에 관한 고저단백질(高低蛋白質) 품종간(品種間)의 생리적(生理的) 차이를 밝히고자 고단백품종(高蛋白品種) 서해(西海)20호(號), 중단백품종(中蛋白品種) 광교(光敎) 및 저단백품종(低蛋白品種) Shelbv를 공시(供試)하여 종실(種實)의 발육상황(發育狀況), 단백질(蛋白質) 및 지방함량(脂肪含量) 변화(變化), disc polyacrylamide gel 전기영동법(電氣泳動法)에 의한 단백질구성분(蛋白質構成分)의 조성변화(組成變化) 등을 조사(調査)하였던 바 그 결과(結果)를 요약(要約)하면 다음과 같다. 1. 대두(大豆) 종실(種實)은 대체(大體)로 개화후(開化後) 22일(日)까지 완만(緩慢)히 그 이후(以後) 20~30일간(日間) 직선적(直線的)으로 급속(急速)히, 그후 5~15일간(日間) 서서히 건물중(乾物中)이 증가(增加)되어 최고(最高)에 달하며, 개화후(開化後) 12일(日)부터 27일(日)까지 단백질함량(蛋白質含量)은 급속(急速)히 감소(減少)되는 반면에 지방함량(脂肪含量)은 급격(急激)히 증가(增加)되고 그 후부터 개화후(開化後) 40~47일(日)까지는 단백질(蛋白質)과 지방함량(脂肪含量) 모두 서서히 증가(增加)된 후 성숙기(成熟期)까지 큰 변화(變化)가 없었다. 2. 고단백품종(高蛋白品種) 서해(西海)20호(號)는 광교(光敎) 및 Shelby에 비해 전(全) 성숙기간(成熟期間)에 대한 비율(比率)로 보아 성숙초기(成熟初期)의 단백질(蛋白質) 함량(含量) 감소기간(減少期間)이 짧고 감소율(減少率)도 적었으며 그후 단백질함량(蛋白質含量) 증가기간(增加期間)이 길고 증가율(增加率)도 큰 특성(特性)을 보였으나, 지방(脂肪) 축적(蓄積)은 일찍 정지(停止)되었다. 3. 저단백(低蛋白) 고지방품종(高脂肪品種) Shelby는 서해(西海)20호(號) 및 광교(光敎)에 비해 전(全) 성숙기간(成熟期間)에 대한 단백질함량(蛋白質含量) 감소기간(減少期間)이 길고 증가기간(增加期間)은 짧았으며, 지방함량(脂肪含量)의 증가기간(增加期間)이 특히 길었다. 4. 종실(種實)의 성숙과정중(成熟過程中) 단백질구성분(蛋白質構成分)의 변화양상(變化樣相)은 품종간(品種間) 차(差)가 뚜렷하였고, 완숙종실(完熟種實)의 단백질구성분(蛋白質構成分)들이 모두 출현(出現)하는 시기(時期)는 종실(種實)의 단백질함량(蛋白質含量) 감소(減少)가 끝난 시기(時期)와 대체(大體)로 일치(一致)되었으며, 상대이동도(相對移動度)가 가장 작은 단백질(蛋白質)(a'=Rm 0.03)이 개화후(開花後) 17일(日)까지는 존재(存在)하였으나 그 이후(以後)에는 없었다. 5. 고단백품종(高蛋白品種) 서해(西海)20호(號)는 광교(光敎) 및 Shelby에 비해 단백질구성분(蛋白質構成分) a($a_1+a_2+a_3$)의 조성비율(組成比率)이 성숙초기(成熟初期)에서부터 계속 높았고 개화후(開花後) 47일(日)까지 계속 증가(增加)되었으나, 광교(光敎)와 Shelby에서는 구성분(構成分) a의 조성비율(組成比率)이 개화후(開花後) 27일경(日頃) 이후(以後) 거의 변화(變化)되지 않았다.

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한국 불교음악의 역사적 전개 고찰과 전망 (Consideration and Prospect of the Historical Development of The Korean Buddhist music)

  • 송지원
    • 공연문화연구
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    • 제42호
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    • pp.77-106
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    • 2021
  • 한국에서 전개된 불교음악의 역사를 살펴보려면 이 땅에 불교가 처음 유입된 고구려 소수림왕 2년(372)부터 현재에 이르는 시기까지를 모두 아울러야 할 것이다. 이는 1,600년이 넘는 시간 속의 전개 양상을 고찰해야 하는 일이라 연구 범위가 넓다는 한계를 지닌다. 그럼에도 이 글은 그 긴 시간 동안 펼쳐진 한국 불교음악의 역사적 전개가 어떻게 이루어졌는지 고찰함으로써 21세기 이후 불교음악이 이 땅에서 어떠한 양상으로 펼쳐져야 하는지 생각해 보는 것을 그 목적으로 한다. 삼국시대 이후 고려, 조선을 거쳐 일제강점기, 현재에 이르는 동안 펼쳐진 불교음악의 역사는 '불교 성쇄의 역사'와 궤를 같이 하며 전개되어 왔다. 왕실의 비호가 있던 삼국시대와 고려시대 불교음악의 양상과 억불숭유정책이 펼쳐진 조선시대, 그리고 불교가 탄압의 대상이 되었던 일제강점기, 대중 포교를 위해 불교음악의 새로운 길을 모색해야 하는 현재의 불교음악은 그 긴 시간만큼이나 역사적 전개 양상도 다양하게 이루어졌다. 이는 각 시기별로 불교음악의 주요한 관점과 과제가 무엇이었는지 구분해서 시대별 특징을 밝혀야 하는 작업을 필요로 하고 있다. 이 글은 좁은 의미의 불교음악을 통칭하는 '범패'의 역사만이 아닌, 이 땅에서 소통된 '불교적 성격을 띤 불교음악'을 모두 포함시키고, 20세기 이후 새롭게 만들어진 찬불가 계통의 음악까지를 모두 대상으로 하여 이 땅에서 펼쳐진 '불교와 관련된 음악의 역사적 전개'에 대해 살펴본 것이다. 조선 전기의 승려들이 부른 명칭가곡, 조선시대에 대중 포교를 위해 만든 음악, '화청'의 존재 의미, 조선시대 음악에 남이 있는 불교음악의 흔적을 파악해 보는 일도 이 글의 과제가 될 것이다.

Impact of antimicrobial resistance in the $21^{st}$ century

  • Song, Jae-Hoon
    • 한국미생물생명공학회:학술대회논문집
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    • 한국미생물생명공학회 2000년도 Proceedings of 2000 KSAM International Symposium and Spring Meeting
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    • pp.3-6
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    • 2000
  • Antimicrobial resistance has been a well-recognized problem ever since the introduction of penicillin into clinical use. History of antimicrobial development can be categorized based on the major antibiotics that had been developed against emerging resistant $pathogens^1$. In the first period from 1940 to 1960, penicillin was a dominating antibiotic called as a "magic bullet", although S.aureus armed with penicillinase led antimicrobial era to the second period in 1960s and 1970s. The second stage was characterized by broad-spectrum penicillins and early generation cephalosporins. During this period, nosocomial infections due to gram-negative bacilli became more prevalent, while those caused by S.aureus declined. A variety of new antimicrobial agents with distinct mechanism of action including new generation cephalosporins, monobactams, carbapenems, ${\beta}$-lactamase inhibitors, and quinolones characterized the third period from 1980s to 1990s. However, extensive use of wide variety of antibiotics in the community and hospitals has fueled the crisis in emerging antimicrobial resistance. Newly appeared drug-resistant Streptococcus pneumoniae (DRSP), vancomycin-resistant enterococci (VRE), extended-spectrum ${\beta}$-lactamase-producing Klebsiella, and VRSA have posed a serious threat in many parts of the world. Given the recent epidemiology of antimicrobial resistance and its clinical impact, there is no greater challenge related to emerging infections than the emergence of antibiotic resistance. Problems of antimicrobial resistance can be amplified by the fact that resistant clones or genes can spread within or between the species as well as to geographically distant areas which leads to a global concern$^2$. Antimicrobial resistance is primarily generated and promoted by increased use of antimicrobial agents. Unfortunately, as many as 50 % of prescriptions for antibiotics are reported to be inappropriate$^3$. Injudicious use of antibiotics even for viral upper respiratory infections is a universal phenomenon in every part of the world. The use of large quantities of antibiotics in the animal health industry and farming is another major factor contributing to selection of antibiotic resistance. In addition to these background factors, the tremendous increase in the immunocompromised hosts, popular use of invasive medical interventions, and increase in travel and mixing of human populations are contributing to the resurgence and spread of antimicrobial resistance$^4$. Antimicrobial resistance has critical impact on modem medicine both in clinical and economic aspect. Patients with previously treatable infections may have fatal outcome due to therapeutic failure that is unusual event no more. The potential economic impact of antimicrobial resistance is actually uncountable. With the increase in the problems of resistant organisms in the 21st century, however, additional health care costs for this problem must be enormously increasing.

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한국간호교육 100년 발달사적 연구(1900-2000) (History of Korean Nursing Education (1900-2000))

  • 이소우
    • 한국간호교육학회지
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    • 제6권2호
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    • pp.303-326
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    • 2000
  • Only one hundred years of history in nursing education in Korea is not enough to develop the subject fully as a science. However, the development of Korean nursing education is a great historical event, because Korean nursing education has been accepted by a male-oriented Korean society and has led to a new paradigm in the new millenium. These results are largely due to the Korean people's high enthusiasm for education, as well as Korean women's diligence. I think these 100 years of history can be divided into five periods: (1) the Sunlight period (1900-1911) (2) the New born period (1912-1945) (3) the Settle-down period (1946-1960) (4) the Marked Growth period (1961-1980) (5) the Jumping Period (1981-2000) These classifications are characterized by changes in the educational system, a changed nursing curriculum, educational goals, educational outcomes, and implications. The characteristics of historical development of Korean nursing education was evaluated in three dimensions: structures, contents, and outcome. The structure of Korean nursing education consists of a 3-year program and a 4-year program. Most nursing leaders in Korea hope that these two programs will converge into one system. Secondly, the contents of nursing education in Korea underwent very active changes, according to historical development. These changes in the nursing curriculum have been developed to provide a professional education and develop nursing education as a modern science. Lastly, as to the results of nursing education in Korea, the education was needed to turn out advanced specialists in nursing. In the new millenium, knowledge and information will be the driving forces behind social development. A nation's level of development and creativity in nursing education is the most potent determinant of the future of Korean nursing. The best way to prepare for future challenges will be to create the backbone of a nursing education system. Hence, well-educated nurses in graduate programs should be turned into advanced specialists in nursing. These groups will upgrade the image of Korean nurses, and will have strong influence to improve patient care and the health situation in Korea.

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조선시대 여성저고리의 그리드체계 (The Grid System of Women's Jeogori in Joseon Dynasty)

  • 한은혜
    • 복식
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    • 제62권6호
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    • pp.200-217
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    • 2012
  • The purpose of this research is to examine the specificity of grids to define the characteristics of clothes styles in the Joseon Dynasty period. The significance of examining of the specificity of grids is to find out arbitrary types of the features of grids involved in structuring the Jeogori in the Joseon Dynasty period one by one. The Visual Linguistic Theory was introduced as a methodological tool to exquisitely analyze the characteristics of grids in deep structures of Jeogori in the Joseon Dynasty period. This theory strives to examine sample distribution, the distribution of samples by quality and the distribution of the types of ploidy features. Through the examination, the results are as follows. The grid systems of the Jeogori consisted of diverse proportion systems reaching 86 cases, that is, sequence systems composed of multi-functional, multi-combined bodies. Most ornamental grids had feature angles distributed in a range of $2-20^{\circ}$ that showed a common preference for low sloped diagonal lines or small curvature. Although the preference for certain feature angles were prominent, the feature angles that were used were generally distributed evenly among diverse feature angles to show the characteristics of separation. Therefore, Jeogori makers in the Joseon Dynasty period can be considered as having experimented with many proportion systems to show their aesthetics. In conclusion, based on the results of the examination of feature distributions and related methods to allocate ploidy features, O-type accounted for 66% and thus it was identified that the Jeogori was characterized by O-type. Therefore, it was identified that the characteristic of the Jeogori in the Joseon Dynasty period consisted of O-type fractal structures which are formative structures unique to our nation.

1993/1994년을 기점으로 나타난 한반도 여름철 강수량 변동의 종관기후학적 원인 (Change of Synoptic Climatology Associated with the Variation of Summer Rainfall Amount over the Korean Peninsula Around 1993/1994)

  • 김재훈;이태영
    • 대기
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    • 제22권4호
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    • pp.401-413
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    • 2012
  • In this study, an investigation has been carried out to understand 1) temporal variation of rainfall amount in summer over south Korea during the 30-year period of 1979-2008 and 2) the relationship between the variation of rainfall amount and the change of large-scale monsoon circulation around 1993/1994 over East Asia. The analysis of rainfall amount is carried out separately for whole summer (June-August), climatological Changma period of 23 June-23 July, and August to consider variations within summer. To relate the variation of rainfall amount with the change of large-scale circulation, we have considered two 15-year periods of 1979-1993 and 1994-2008. This study has used observations at 58 stations in South Korea and NCEP-NCAR $2.5^{\circ}{\times}2.5^{\circ}$ reanalysis data. The major change in synoptic environment for the Changma period is characterized by the intensified anticyclone over Mongolia during 1994-2008, which results in a weak meridional oscillation of Changma front. As a result, rainfall amount for the Changma period and the frequency of extreme events have significantly increased after 1993/1994. A major change of synoptic environment for August is the significant westward extension of the western Pacific subtropical high, which allows not only more moisture transports but also stronger cyclonic circulation over the Korean peninsula. Rainfall amount for August and frequency of extreme events have also increased after 1993/1994. However, variability of rainfall amount is larger for August than that for the Changma period, with some years showing very dry August (monthly rainfall amount less than 150 mm).

임진왜란기(1592~1598) 출토 포의 형태분석과 일러스트화 (Analysis and Illustration of the Formative Characteristics of Po Discovered During the period of the Japanese Invasion of Korea (1592-1598))

  • 이주영;이경희
    • 복식
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    • 제60권9호
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    • pp.58-76
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    • 2010
  • In this study, the shapes of po worn by military officers who served During the period of Japanese Invasion of Korea(1592-1598) were investigated. Findings of the study can be summarized as follows. Various types of po that military officers usually wore during the period of Japanese Invasion of Korea includes jikryeong, dapho, dopo, cheolik, aekjureum, jangeui, jungchimak and bangryeongpo. Out of these types, cheolik and jungchimak were most often used by the officers. Po that were usually worn by military officers during the period of Japanese Invasion of Korea as above mentioned is characterized as no difference in length between the front and back of the costume, kalgit and a pair of coat strings which are directly attached to po. The sleeves of the costume are bean chaff-shaped in some cases and just narrowly shaped in other cases. Similarly, the outer seop of po was either double-layered or single-layered. For jikryeong and dapho, mu is usually type of outside wrinkle. For dopo, its rear kit has the inner hem whose right and left edges are usually distant, respectively by 6~16cm, from the back center of the costume. Cheolik and aekjureum usually have either fine or broad pleats. For jangeui and jungchimak, mu is usually trapezoid in shape. Among various types of po which were usually worn by military officers during the period of Japanese Invasion of Korea, most representative are jikryeong from the tombs of Bae Cheon jo, dapho from Shin Yeo Gwan, dopo from general Bak and Bae Cheon Jo, cheolik from Nam Yoo and Cho Gyeong, aekjureum from Shin Yeo Gwan, jangeui from Kim Ham, jungchimak from Bae Cheon jo and bangryeongpo from Cho Gyeong.