• KOREAN JOURNAL OF CROP SCIENCE
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• v.30 no.3
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• pp.314-319
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• 1985

In order to observe the differences of several characters related to earliness, seven barley varieties were tested under two different photoperiodic conditions. Final leaf number per main stem under long day did not vary among varieties, but ranged 6 to 7 in early group and 9 to 10 in late group under shortday. Shoot apex of early varieties, Jogangbori and Oweolbori reached to X stage at 24 days, but that of late variety, CI 15446 did to X stag at 32 days after transplanting under short day. Spike length reached to maximum length at 39 days in early group, but at 51 days in late group. Saeolbori, CI 15446 and Hangmi were photo-sensitive, but Jogangbori and Oweolbori were photo-insensitive. Therefore, the photoperiodic response to short day was most responsible to heading time. Those results showed that early heading varieties had the characteristics with less variation of final leaves, less retardation of shoot apex development and spike elongation, and shorter period to flag leaf emergence under short day.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2022.09a
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• pp.79-79
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• 2022

옥수수(Zea mays L.)의 생육 및 수확량은 온도, 일장, 강수량 등에 의해 영향을 밭는다. 본 연구에서는 남부지역 유휴 논을 이용하여 파종시기를 달리하여 옥수수를 재배하였을 때 생육 특성과 수확량을 분석하여 적정 파종시기를 규명하고자 하였다. 3월 하순에서 6월 중순까지 6차로 구분하여 파종하였을 때 출사일수와 성숙일수는 파종기가 늦어질수록 짧아졌다. 옥수수는 단일 및 고온 조건에 의해 생식생장으로의 전환이 빨라지는데, 본 연구에서도 파종이 늦어짐에 따라 단일과 고온에 의해 출웅과 출사가 촉진되었다. 간장과 착수고는 4월 상순까지는 높으나 파종이 지연됨에 따라 짧아졌다. 옥수수의 수량구성요소 중에 이삭장은 5월 하순까지는 유의적인 차이가 없으나 6월에 파종하였을 때에는 짧아졌으며, 이삭직경과 착립장도 파종이 늦어짐에 따라 가늘어지고 짧아져, 파종이 지연되었을 때 생육이 부진함을 알 수 있다. 이삭의 수확량은 4월 상순까지 파종하였을 때에는 800kg/10a 이상으로 높으나, 파종시기가 늦어짐에 따라 점차 감소하여 6월 중순에는 40% 이상 크게 감소하였다. 이는 수량구성요소 중에 이삭장, 이삭직경과 착립장 등 이삭 발달의 부진한 결과이다. 그리고 이삭을 제거한 지상부의 무게는 5월 하순까지의 파종에서는 유의적인 차이가 없으나 6월에는 큰 폭으로 감소하였는데, 이는 영양생장 기간이 짧아짐에 따른 결과로 보인다. 이상의 결과를 토대로 남부지역 논에서 옥수수를 재배할 때에는 늦어도 5월 중·하순까지는 파종하여야 할 것으로 판단된다.

• Journal of The Korean Society of Grassland and Forage Science
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• v.23 no.4
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• pp.265-270
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• 2003

This study was conducted to determine the influence of seeding date on growth, characteristic yield and chemical composition of Italian millet (Setaria italica) from April 20 to May 30, 2003(April 20, May 1, May 20 and May 30) in Jeju. A local variety was seeded on days to heading were lessened as seeding date was delayed. The plant height was longest when seeded on 1 May(131cm) than at the other seeding dates. Stem diameter, number of leaves, leaf length and leaf width had the similar trend with plant height. SPDA reading values were greater at earlier seedings. Fresh forage yield was greatest (43.28MT/ha) at 1 May seeding and decreased gradually before or after this seeding date. Dry matter yield, crude protein yield and total digestible nutrient (TDN) yield had nearly the same tendency with fresh forage yield. Crude protein, crude fat, NFE and TDN contents were greatest at 30 May seeding and then decreased earlier seedings. Crude ash and crude fiber content tended to decreased as seeding was delayed. Based on the these findings, optimum seeding date for forage production of Italian millet seems to be early May in Jeju island.

• Korean Journal of Construction Engineering and Management
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• v.6 no.3 s.25
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• pp.81-89
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• 2005

Delay schedule coming about duration extension is happening essentially because public construction project consist of many sub contractor. The method which can calculate delay day is suggested by many studies in case of happing delay schedule, but It is difficult to apply to real construction project because there is no mention about the control of The law of contract according to delay schedule. The law of Contract which is cost of account has more uncertain problem than FIDIC condition of contract. This study suggests method which can make extension of duration procedure clear in case of happing the reason of design change related with activity duration during carrying on construction, and a submission process of the reason of duration extension and modify schedule making way about section which is basis of calculating contract amount clear.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.24 no.2
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• pp.65-70
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• 2024

In recent years, research on smart factory wireless mobile communication technology that wirelessly remotely controls utilities is being actively conducted. The Wi-SUN (Wireless Smart Utility Network) Alliance proposed a Wi-SUN protocol structure suitable for building a platform such as a smart factory as a new wireless communication standardization standard based on EEE802.15.4g/e. It analyzes the performance of the IEEE802.15.4e Receiver Initiated Transmission(RIT) Mode Media Access Control (MAC) in terms of throughput and latency, and looks at considerations for efficient operation. RIT mode shows that as the check interval becomes longer, delay time and throughput decrease. It was shown that as the traffic load increases, if the RIT check interval is shortened, the delay time can be shortened and throughput can be increased. RIT mode has the advantage of low power consumption and has neutral characteristics between IEEE802.15.4 and CSL mode in terms of delay time and throughput.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.27 no.2
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• pp.163-168
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• 1982

Tobacco seedling which were sown 20 days earlier than conventional, both at 4-5 and 7-8 leaf stages, were once sprayed with ethrel (0, 500, and 1,000 ppm concentrations) and transplanted simultaneously to investigate the subsequent effects. The number of leaves and days to flower were tend to decrease when seedlings were treated at an early developmental stage than at later stage. The highest yield was obtained from seedlings treated with 500 ppm of ethrel at the 4-5 leaf stage, showing 40% increment above conventional seedlings, partly due to more number and bigger size of the leaves. Finally possible mechanisms for the result were discussed.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.48 no.6
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• pp.490-494
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• 2003

To understand flowering response under diverse day-length condition and the movement of floral stimulus, we used six perilla accessions which showed diverse days to flowering. Though the growth phase was reported as irreversible between vegetative and reproductive stage, perilla showed reversible growth phase according to day length increase in May and June. When it sowed in March, flowering response was started in early May and vegetative and reproductive phase was coexisted in late June. When a part of a perilla plant was treated under short day condition, only apical buds on main stem or branches were flowered but other long day conditioned apical buds were not flowered. With this result it is suggested that the floral stimulus can not be transferred to other part of perilla.

• FLOWER RESEARCH JOURNAL
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• v.17 no.4
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• pp.297-302
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• 2009

This study was carried out to investigate the characteristics of rooting and bud break of single-stemmed roses (Rosa hybrida L. 'Rate Rose' and 'Teresa') as affected by axillary bud position and leaf area of cuttings derived from different growth stage of the mother shoots. In fact, both rooting and budbreak of single-stemmed roses were not influenced by growth stage of mother shoots, with showing more than 95% in all treatment related to mother shoot maturity. 'Rote Rose' required 34 days to average rooting and budbreak after cutting, whereas 'Teresa' did only 18 days to budbreak which was 9 days faster than rooting. Rooting and bud break needed more time and showed lower percent as the axillaty bud position for cuttings went down to the base of mother shoots. Especially 'Teresa' showed 12 days of delay to budbreak and 14.4% decrease in budbreak. Also, the increase in leaf area of cuttings accelerated rooting and budbreak, of which the time was shorter and the percent was higher.

• Korean journal of applied entomology
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• v.47 no.1
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• pp.23-29
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• 2008

The biology of indian meal moth and maize weevil on the trehalose gene introduced rice (var 'Nakdong') (T-Nakdong) was compared to that on the rice without gene introduction (Nakdong) at $28{\pm}1.0^{\circ}C$. Development of the both two insects was significantly delayed; on T-Nakdong, the developmental periods of female moth $({\pm}SE)$ and weevil were $38.46{\pm}0.42\;and\;36.38{\pm}0.28days$, respectively. Whereas those on Nakdong were $36.38{\pm}0.28\;and\;34.33{\pm}0.18$, respectively. Net reproduction rate of Indian meal moth on T-Nakdong $(3.0{\pm}0.14)$ was significantly lower than that on Nakdong $(9.25{\pm}0.13)$, due to the lower emergence rate $(21.08{\pm}0.04%\;vs\;48.30{\pm}0.06%)$. The life table statistics of maize weevil on T-Nakdong was estimated to be similar to those on Nakdong. The delayed development of T-Nakdong suggested that the factor for development of the insects could be changed by the introduction of trehalose gene into the rice variety.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.26 no.2
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• pp.125-136
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• 1981

This experiment was conducted to study the influence of different cultivation periods on some morphological and agronomic characteristics of rice plant at Iri, the Honam plain, in 1979. Early maturing varieties showed little delay in heading with late transplanting, but intermediate and late maturing varieties showed more than 7 day delay in heading. The number of days required to reach heading was over 55 and 67 days after transplanting in early and intermediate-late maturing varieties, respectively. There was significantly postitive correlation between the length of vegetative stage and the grain yield. The mean temperature during ripening period was significantly correlated with the grain yield and the percentage of filled grains. The length, width, and thickness of leaf increased with earlier transplanting and the elongation degree between upper and lower leaves showed the same tendency. The productivity of dry matter and the translocation rate of photosynthate to spikelet decreased with late transplanting mainly due to low temperature. LAI was also influenced by transplanting date showing close correlation with yield. Early transplanting was desirable for assimilation and dry matter accumulation.