• Title/Summary/Keyword: 4.19 세대

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A Study on the E-book Usage Behavior of University Library by University Students: Focusing on the Impact of COVID-19 (Z세대 대학생들의 대학도서관의 전자책 이용 행태에 관한 연구 - 코로나19의 영향을 중심으로 -)

  • Su Hyun, Jang;Youn Suh, Park;Young Joon, Nam
    • Journal of the Korean BIBLIA Society for library and Information Science
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    • v.33 no.4
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    • pp.181-205
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    • 2022
  • This study attempted to confirm the reading behavior of Generation Z college students in Korea, including their perception of e-book use, and to find out the changes caused by COVID-19. To this end, university students across the country were surveyed for e-book recognition and use, e-book usage status, e-book preference recognition, and comparison items of university libraries and e-book use before and after COVID-19. As a result of the analysis, university libraries had a significant impact on the use of e-books by Generation Z college students, and COVID-19 partially affected reading behavior, such as a significant change in the average daily reading time of Generation Z college students.

Studies on the Seasonal Increase of the Population of the Smallerbrown Planthopper, Laodelphax striatellus(Fallen) (애멸구의 세대별 증식동태에 관한 연구 -기주식물의 종류와 생육단계와 증식과의 관계-)

  • Hyun Jai Sun;Woo Kun Suk;Ryoo Mun Il
    • Korean journal of applied entomology
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    • v.16 no.1 s.30
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    • pp.13-19
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    • 1977
  • The smaller brown planthopper overwinters mostly as the fourth instar nymph. The emerged adult disperses to winter barley or wheat plants. The adult of the first generation disperses into the rice field, and spends three generations in the rice field. The population densities of the adults of the first generation and the overall density of the second generations are the most important in relation to the incidents of the rice stripe disease which is transmitted by this insects. This study was intended to analyse the population increases in these important generations in relation to the kind and the different growing stage of the host plants. The insects were reared on potted host plants of different growing stage in the insect cages. The population increases of the insects in the cages were compared with those on the rice seedlings in the laboratory. The results are as follows: 1. The average longevities of the adults of the generations were 13.4 days for the overwintered, 12.9 days for the first, and 10.2 days for the second generation, and showed no significant differences between the generations even they seemed to be shorter than normal condition probably caused by the frequent disturbance at the time of food renewal in 2 or 3 days. 2. When they were reared on the rice seedling, the average numbers of the eggs per female were 131.2 for the overwintered generation, 124.9 for the first generation grown on the barley, and 142.3 for the second generation grown on rice, and shelved no significant differences between the generations. More than $90\%$ of the eggs were laid within 3 weeks. 3. The hatchabilities of the eggs laid on the rice seedling in laboratory were $77.4\%$ for the first generation, $93.1\%$ for the second generation and $62.1\%$ for the third generation. The estimated hatchabilities of the eggs were $67.5\%$ for the first generation, $84.1\%$for the second generation, and $21.9\%$ for the third generation with the growing plants on the plots. The hatchability on the eggs laid by the adults infested on the barley on May 17 was $13.5\%$ compared with $67.5\%$ for the eggs laid by those infested on barley in late April. 4. The average total nymphal periods were 19.4 days for the first generation, and 13.3 days for the second generation in the laboratory and the mortalities of the nymphs seemed to related with the growing stages of the host plants. 5. With the pot experiments, the average per cents of the emerged adults were $37.2\%$ for the first generation, $55.3\%$ for the second generation, and $11.6\%$, for the third generation. The average numbers of the emerged adults were $7.4\%$ for the pots infested on the barley on May 17, instead of $37.2\%$ adults for those infested in late April. 6. From above results, it may suggest that the innate qualities of the insect are not significantly different between generations, and the differences in the increase of the population for the generations might effected considerably by the differences in the physiological conditions of tile host plant, besides the differences in physical and other biological factors.

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ETRI의 4세대 무선전송시스템 연구개발

  • 이석규;장경희;황승구;한기철
    • Information and Communications Magazine
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    • v.19 no.7
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    • pp.86-101
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    • 2002
  • 사용자 요구의 다양화와 그에 따른 트래픽 증가 등 현재의 IMT-2000 기반에서 수용할 수 없는 보다 복잡한 이동 멀티미디어 환경이 도래하고 있다. 이러한 이동 멀티미디어 서비스를 원활히 제공하기 위해 ITU-R을 중심으로 한 전세계 이동통신 업계는 이미 4G 시스템 규격 및 개발에 상당한 진전을 보이고 있다. 이에 따라 ETRI도 지난 2002년 1월부터 4세대 동통신 초고속 패킷 무선전송 기술 연구 개발에 착수하였다. 이 연구 개발은 크게 전송 시스템과 네트워크 분야로 나뉘어 진행되고 있는데, 본 고에서는 Low-tier 서비스를 위한 HMI 시스템과 High- t 서비스를 위한 HMM 시스템을 중심으로 ETRI의 세대 무선 전송시스템 개발 계획 전개 방향 및 목표 등을 간략하게 소개하고자 한다.

Resistance Development and Cross-Resistance of Diamondback Moth (Lepidoptera: Plutellidae) by Single Selection of Several Insecticides (단제도태에 의한 배추좀나방(Plutella xylostella)의 약제저항성 발당과 교차저항성에 관한 연구)

  • 조영식;이승찬
    • Korean journal of applied entomology
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    • v.33 no.4
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    • pp.242-249
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    • 1994
  • These studles were conducted to investigate the development of chem~cal resistance and cross.resista. nce m dlarnondback moth (Piuteiia xylostella L). The resistance development of diamondback moth greatly vaned under single selection of five insectlades. The tnflumuron and lambda cyhalothnn strains at 8th selected generation showed 374- and 29.l.fold resistant levels. respectively, as compared with the susceptible strain. However, the Baciilus thuringiensis-seleded at 8th selected generatLon exhibited 240-fold resistant level. and the prothiophos-selected at 8th generation revealed 14.3-fold resistant !eve1 while the cartap hydrochloride-selected at 8th generailon showed 9.1-fold resistant level Prothiophos- selected strain showed low cross-resistance level to cartap hydrochloride, while this strain exhibited no cross-resistance of 1.3 to 2.8-fold to other msectlcides. Cartap hydrochlonde- seleded strain showed 19.9-fold. a high cross-resistance to lambda cyhalothrin, but this strain showed 2.2-34 fold, no cross resistance to other insecticide. Lambda cyhalothnn-selected strain exhibited cross-resistance to cartap hydrochlolide and prothiophas. Triflumuron-seleded strain showed 1.3-4.9 fold. no cross-resistance to other ~nsectic~dTe he B. ihuring~ensis-selededs train showed no cross-resistance to other insecticides.

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Mobile Access Network Technology (이동통신 액세스 망 기술)

  • Shin, D.J.;Park, I.S.;Park, J.S.;Jang, M.S.;Song, P.J.;Nam, S.W.
    • Electronics and Telecommunications Trends
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    • v.19 no.3 s.87
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    • pp.41-50
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    • 2004
  • 본 고에서는 이동통신 액세스 망의 기술 동향에 대하여 4세대 이동통신 액세스 망으로의 진화 관점에서 살펴 본다. 주요 표준화 기관인 3GPP2, 3GPP2, MWIF의 연구결과를 중심으로 3세대 이후의 기술에 대한 표준화 연구를 살펴 보며, 액세스 망이 추구하는 목표 및 요구사항에 따른 액세스 망의 구조를 예측해 본다. 핵심 망 및 단말을 포함하여 향후에는 액세스 망도 인터넷 프로토콜 기반의 패킷 망으로 발전될 것이며, 구조 및 인터페이스의 개방화, 기능의 분산화를 토대로 기존의 다양한 액세스 망을 수용하는 4세대의 액세스 망으로 발전될 것이다. 따라서 마지막으로 이러한 추세에 따른 3세대 이후, 즉 4세대를 지향하는 이동통신 액세스 망에 대하여 요구사항 및 기능, 구조 등에 대하여 분석해 본다.

4.19세대의 청년기 독서편력

  • Jin, Deok-Gyu
    • The Korean Publising Journal, Monthly
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    • s.104
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    • pp.6-7
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    • 1992
  • 그토록 많은 지적 방황과 정신적 표류과정을 거쳤으면서도 우리들 세대는 그래도 비교적 행복했던 것 같다. 현실의 암담함이나 삶의 고달픔이 힘겹지 않은 것은 아니었지만, 그것을 견디어낼 수 있었던 것은 좋은 스승이 있었고 함께 고뇌했떤 친구가 있었으며 특히 "사상계"가 있었기 때문인 것 같다.

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Preference Factors of the Korean MZ Generation vis-à-vis the Online Programs of Museums Abroad (비대면 시대 해외 뮤지엄의 온라인 프로그램에 대한 한국 MZ 세대의 선호요인 연구)

  • Kwak, Song-Bi;Kwon, Cheeyun
    • Journal of Digital Convergence
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    • v.20 no.4
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    • pp.565-573
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    • 2022
  • This study aims to analyze the preference factors of the Korean MZ generation with regards to the online programs developed by museums abroad during the COVID-19 pandemic. World renown museums such as the British Museum, the National Gallery of London, Van Gogh Museum, J. Paul Getty Museum, Hasting Contemporary, Uffizi Gallery, and the Guggenheim Museum tackled the social-distancing situation with various creative online programs and events to continue their role as socially relevant institutions. Ten acclaimed programs conducted by these museums were shown to the Korean MZ generation, the most digitally savvy and frequent visitors to museums, to extract their responses to the various types of programs. The study showed that the Korean MZ generation prefer online programs which most closely reflect the onsite experience of a museum, and online contents with educational elements.

Molting Patterns of Flight Feathers of Immature Steller's Sea Eagle(Haliaeetus pelagicus) Raised in Captivity (사육상태에서 자란 참수리(Haliaeetus pelagicus) 미성조 날개깃의 깃갈이 방식)

  • Kang, Seung-Gu;Lee, In-Sup
    • Journal of Life Science
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    • v.19 no.1
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    • pp.58-64
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    • 2009
  • This study was conducted to know the molting sequence and the aging points of flight feathers of steller's sea eagles (Haliaeetus pelagicus). For this study, two captive immature steller's sea eagles raised at the Ornithology Laboratory attached to Kyungsung University were surveyed for five years from Nov. 2000 to Nov. 2005. The survey indicated that the first molting began in July of the second year, and the primaries of P1-3, the secondaries of S18-19 (female), S17-18 (male), and S1 and S4 were replaced by one-time with second generation feathers. Generally molting stopped during the winter period, but a few feathers continued to molt during the winter. The two secondaries of S18-19 (female) and S17-18 (male) always molted every year but some of the juvenile secondaries (male: S10, S11, etc) retained for 2 or 3 years. In the molting order of primaries, the first molting started at P1 and it proceeded to P10 of outside. In the secondaries, the first molting started at S17(male) and S19(female), and it proceeded to outside. After that molting it started at S1 and proceeded to inside. In the other secondaries, the pattern of molting which proceeded in the mid-part of the secondaries was usually beginning in several different points at the same time. The molting seemed as if it depends on both the conditions of the individuals and the environment, so it was very difficult to explain the molting pattern in the mid-part of the secondaries. The longer quills (P7, P8) required for more than 68 days to develop. In the comparison of the length in the remiges between the first and the second generation feathers, the first generation feathers were the larger than that of the second. And the reduction of the length between the second and the third generation feathers was a few. The reduction of the length between the third and the fourth generation feathers was slight. The juvenile primaries were dark brown with a whitish base, which could be observed until the second or the third generation feathers (in their third or fourth winter plumage).

Studies on the Nymphal Parasitism, Haplogonatopus atratus Esaki at Hashimoto (Dryinidae) of the Small Brown Planthopper, Laodelphax striatellus Fallen (I) (애멸구 약충기생봉(Haplogonatopus atratus)에 관한 연구 (I))

  • Kim Jeong Bu;Kim Chang Hyo;Cho Dong Jin
    • Korean journal of applied entomology
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    • v.23 no.2 s.59
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    • pp.116-118
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    • 1984
  • This study was carried out to know the percentage of parasitism and host preference of Haplogonatopus atratus (Dryinidae) in the nymphs of small brown planthopper. The percentages of parasitism in the nymphal stage of planthopper at each generation were $19.2\%$ for overwinterd generation, $10.8\%$ for the 1st generation on barley field and $21.5\%$ for the 2nd generation on paddy field, respectively. The percents of the parasitism for the respective instars were $78.2\%$(3rd), $17.5\%$(End), and $4.2\%$(4th) when various developmental stages of the planthopper had been caged together. No parasitized individual was found for the instars of the 1st, the 5th and the adult.

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