• Journal of Ecology and Environment
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• 제31권1호
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• pp.31-36
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• 2008

Larvae of the long-tailed clawed salamander, Onychodactylus fischeri, have a relatively long larval period, spending a year or more within the stream where they hatch; therefore, a well-established larval population could be critical for the conservation of adult populations. To study the population dynamics of long-tailed clawed salamander larvae, we surveyed a field population once or twice a month from September, 2005 to June, 2006, and determined the age of larval clawed salamanders collected from three different populations in October, 2004 using skeletochronology. The age of long-tailed clawed salamander larvae ranged from 0 to 3 years. New recruitment of larvae in the population primarily occurred in November, 2005, and mid-March, 2006. Larvae with a snout-vent length of more than 30 mm disappeared from the streams in September, 2005, suggesting that two to three year-old clawed salamander larvae metamorphosed during this period.

• 한국수산과학회지
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• 제53권1호
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• pp.1-8
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• 2020

The reproductive biology of largehead hairtail Trichiurus japonicus, from near Jeju Island, Korea was investigated based on 4,384 individuals collected by commercial vessel from November 2016 to October 2019. There were more female specimens than male specimens (2.64:1). T. japonicus preanal lengths (PL) ranged from 10.5 to 53.5 cm; the relationships between PL and body weight (BW) were BW=0.0103PL^3.1293 for females and BW=0.0106PL^3.1251 for males. Monthly changes in gonadosomatic index were analyzed to estimate spawning season. The spawning period ranged from June to November. The size-frequency distribution of eggs suggested that T. japonicus exhibits multiple-spawning during a spawning period. The minimum size of females at maturity was 18.2 cm, while the size at sexual maturity was 25.0 cm.

• 한국수산과학회지
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• 제53권1호
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• pp.98-102
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• 2020

We examined the comparative spawning ecology of daggertooth pike conger Mureanesox cinereus and common pike conger M. bagio in the South Sea of Korea from May 2018 to December 2019. In the South Sea of Korea, the mean total length (TL) of M. cinereus was significantly smaller than that of M. bagio. The sex ratios of both species were skewed toward females. The spawning period of M. cinereus was from June to October, while the spawning period of M. bagio was from August to October. The lengths at 50%, 75%, and 97.5% sexual maturity of M. cinereus females were estimated as 54.6 cm, 60.4 cm, and 74.1 cm TL, respectively. It was not possible to estimate lengths at sexual maturity for M. bagio in the South Sea of Korea due to the absence of immature stages.

• 항공우주시스템공학회지
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• 제8권3호
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• pp.14-19
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• 2014

When a helicopter lands on a ship deck in high sea states, one of main difficulties is the ship motion by sea wave, In case of a manned helicopter, a pilot lands a helicopter on the deck during quiescent period of ship motion, which is perceived from different visual cues around landing spot. The capability to predict this quiescent period is very important especially for shipboard recovery of VTOL UAV in harsh environments. This paper describes how to predict heave motion of a ship for shipboard landing of a VTOL UAV. For simulation, ship motion by sea wave was generated using a 4,000 ton class US destroyer model. Heave motion of ship deck was predicted by applying auto-regression method to generated time series data of ship motion.

• 대기
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• 제22권4호
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• pp.449-454
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• 2012

This study presents the long-term variability of spring precipitation over the Korean peninsula. It is found that the significant interdecadal change in the spring precipitation has occurred around year 1991. Over the Korean peninsula the precipitation for the post-1991 period increased by about 30 mm per year in CMAP and station-measured data compared to the precipitation prior to year 1991. Due to an increased baroclinicity during the later period, the low-level negative pressure anomaly has developed with its center over northern Japan. Korea is situated at the western end of the negative pressure anomaly, receiving moisture from westerly winds and producing more precipitation. Also, we estimate the change in the near future (years 2020~2040) spring precipitation using six best performing Coupled Model Intercomparison Project 3 (CMIP3) models. These best model ensemble mean shows that spring precipitation is anticipated to increase by about 4% due to the strengthened westerlies accompanied by the northwestern enhancement of the North Pacific subtropical high.

• 대한방사성의약품학회지
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• 제5권1호
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• pp.3-10
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• 2019

The activities per volume of $^{188}Re$ and $^{99m}Tc$ from their generators are dependent on the specific activity of their mother nuclides $^{188}W$ and $^{99}Mo$ respectively. After a particular lapse of time, the eluted RI activity is exponentially reduced and thus cannot satisfy the needs of clinical application. The purpose of this study is to develop a $^{188}Re$ and $^{99m}Tc$ concentration device with a compact size that can extend the period of use as well as conveniently concentrate the RI. We designed the concentration module by including two-different check valves that do not required any manual on-off operations. In these concentration process, cation exchange resin embedded with Ag and anion exchange resins were used. After completing the concentrating step, the recovering yield was identified to be more than 93% for $^{188}Re$ generators and 88% for $^{99m}Tc$ generators. Moreover, all these procedures were done within 5 min.

• 수산해양기술연구
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• 제47권3호
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• pp.248-256
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• 2011

The inherent efficiency of a ship would be prior to any other quality factors in ship's safety, because lack of it may give rise to a serious sea casuality even if it were a light mistake in operation. And the representative casualty comes from a deficiency of stability and an operating error combined would be capsizing. The Korean offshore large purseiner looks to have a structural weak point with small range of stability in spite of her big initial metacentric height, and have various type of roll reduction devices in order to cover up the defect. The aim of this study is to grasp for the roll reduction characteristics of the purseiner with bilge keel only and a stern keel additionally attached. The results are summarized as follows; The rolling angle of the model ship was increased in accordance with increase of the wave period and height, especially at close to the natural wave period of her, and the trends were more distinguished in the situation of bilge keel only installation than in the stern keel additionally installed. And stern keel has not noticeable effect on the reduction of the roll in the light ship condition, but has a little effect in full load condition.

• 한국환경보건학회:학술대회논문집
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• 한국환경보건학회 2003년도 Challenges and Achievements in Environmental Health
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• pp.171-173
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• 2003

Bisphenol A (4,4'-isopropylidenediphenol, C$\_$15/H$\_$16/O$_2$) is the monomer used in the manufacture of polycarbonate. Polycarbonate, in turn, is used in a wide array of plastic products, with new applications continuously being developed. Also it has been used to produce epoxy resins and polycarbonate plastics for food container. This study was carried out to investigate the effects of bisphenol A on lactation period to dams and F1, Sprague-Dawley females were mated with on 2:1 ratio basis. Various doses of bisphenol A (0, 2, 20, 200, and 2,000 $\mu\textrm{g}$/kg) were daily administered to females for 21 days after parturition. Dams and offsprings were sacrificed at the time of weaning. The results were as follows, 2000 $\mu\textrm{g}$/kg of bisphenol A decreased the dams' body weight at post-partum 18 days and also 200 and 2000 $\mu\textrm{g}$/kg of bisphenol A decreased the body weight of neonates at the days of post-partum 21 days. Bisphenol A increased the relative weights of liver and spleen in male offsprings, depending on the doses. But female offsprings showed high relative organ weights of ovaries, and low relative organ weights of uterine in a some dose-response manners. High dose of bisphenol A induced low viability of neonates exposed during lactation period. The dams treated with bisphenol A showed prematured estrous stage. Bisphenol A was recovered about 21.2% average in serum of dams, and also in offsprings'. The results indicate that the bisphenol A induces estrous cycle during lactation period in dams, also reaches to the of offspring through breast milk. Thus bisphenol A exopsed to dams and neonates via lactation induces some estrogenic and toxic effects.

• 한국식품조리과학회지
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• 제23권3호통권99호
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• pp.281-287
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• 2007

본 연구에서는 김치를 활용한 다용도 소스 개발의 목적으로 배추김치를 제조하여 잘 숙성된 김치를 분쇄한 다음 부재료로 전분, 당, 식초, 소금을 혼합하여 김치소스를 제조한 후 5$^{\circ}$C에서 91일 동안 저장하면서 저장기간에 따른 품질특성 및 관능적 특성을 살펴보았다. 즉, 김치소스 제조는 배추김치에 부재료와 백년초분말을 1.0% 첨가한 것으로 하였다. 품질특성을 조사한 결과 pH의 경우 저장초기는 pH 4.1이다가 저장 91일이 되어도 거의 같은 수준을 유지하여 변화가 없게 나타났다. 총산도는 저장기간이 증가함에 따라 각 소스별 비슷한 경향으로 증가하였으나 큰 변화는 보이지 않았다. 색은 천연색소를 첨가하여 안정성을 나타내었으며, 비타민 C와 점도의 변화는 저장기간이 증가할수록 비슷한 경향으로 감소하는 경향을 보였다. 또한 저장기간별 김치소스의 총균수 및 유산균수의 변화를 살펴 본 결과 비슷한 양상으로서 저장초기에서 거의 변화가 없다가 저장 약 20일에는 약간 증가했다가 서서히 감소하기 시작하여 저장 91일까지는 거의 변화 없이 다소 저하되는 경향을 보였다. 관능적 특성은 저장기간에 따라 다소 유의적인 차이는 있었으며, 가공된 김치소스에서도 소비자기호도 조사에서 모든 평가 항목에서 높게 평가되었다.

• 복식
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• 제57권6호
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• pp.17-31
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• 2007

Fashion of one period is symbolic and figurative means of expression reflecting spirit, ideology, emotion and aesthetic values of that period. Designs of school uniforms fer girls also went through changes in various shapes along with changes in sociocultural and philosophical backgrounds in each period. Thus, in this study, in examining girls' school uniforms, how girls' school uniforms have evolved with what kind of design characteristics was observed along with process of historical changes, and investigation was made on realistic conditions of girls school uniforms since 1996 when active advancements in school uniform design were started. Also, through examination of girls' school uniform designs from homepage of large student uniform companies and catalogues, characteristics of girls' school uniforms after 1996 were observed. On the result, we could know that girl's school uniforms from 1996 to 2006 were designed in various forms compared to those of the past time and changing Arends of the era were reflected on the school uniform designs. Narrow waistline, shorter blouse, changes in the length of jacket and skirt showed that current school uniform designs pursue the fashionable and trendy designs unlike those of the past times that were uniform and strict. This study include organizing characteristics of girls' school uniform designs by each period, providing fundamental and realistic data for clothes manufacturing and marketing activities through analysis on designs of girls' school uniforms since 1996, and providing directions for future school uniform designs.