• 한국음향학회지
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• 제35권1호
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• pp.16-23
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• 2016

본 논문은 무한 원통형 실린더의 자유진동에서 발생하는 고유진동수(eigenfrequency)를 구하는 3가지 방법에 대해 다루었다. 일반적인 경우에 적용될 수 있는 탄성 이론을 적용한 방법과 얇은 두께의 실린더에 효율적으로 적용될 수 있는 얇은 원통형 쉘 이론을 적용한 방법, 유한요소법(FEM: Finite Element Method)을 통한 수치 해석 방법을 통해 구해진 결과에 대한 비교 및 검증을 수행하였다. 주어진 실린더의 외반경에 두께를 서로 달리하여 1 kHz 이하에 존재하는 원통형 쉘의 고유진동수를 구하였고 모드수와 두께의 변화에 따른 이들 결과에 대해 관찰하였다.

• International Journal of Industrial Entomology and Biomaterials
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• 제7권2호
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• pp.117-125
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• 2003

To know the impact of female pupal weight corresponding to the male cocoon shell weight upon fecundity, hatchability and percentage of non-viable eggs, the experimental multivoltine breeds namely BL67 and 96A were categorised into low, medium and high batches according to the weight of female pupae and male cocoon shells and moths emerged from low, medium and high female pupae were allowed to mate withmoths emerged from low, medium and high male cocoon shells. Both the experimental breeds of BL67 and 96A revealed a fairl trend in fecundity for high batch ＞ medium batch ＞ low batch. When data were statistically analysed, a significant (p ＜ 0.05) and a highly significant (p ＜ 0.01) increase in fecundity was observed in the medium and high batches of BL67 during November - December, 2002 whereas highly significant (p ＜ 0.01) increase was observed in the high batches of 96A during November - December, 2002. Data revealed a highly significant (p ＜ 0.01) increase in fecundity in medium and high batches of both the breeds during January - February, 2003. More interestingly, a significant (p ＜ 0.05) reduction was noted in percentage of non-viable eggs in high batches of 96A during January - February, 2003. But no significant variation in hatchability was noticed due to the effect of differential female pupal weight and male cocoon shell weight.

• Bulletin of the Korean Chemical Society
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• 제30권1호
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• pp.129-132
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• 2009

Monodisperse ZnS colloidal particles with precisely specified diameters over a broad size range were synthesized by controlled aggregation. Sub-10nm ZnS seed crystals were first nucleated at ambient temperature and then grown at an elevated temperature, which produced large polydisperse colloidal particles. Subsequent rapid thermal quenching and heating processes induced a number of secondary nucleations in addition to growing the large polydisperse microparticles which were finally removed by centrifugation and discarded at the completion of the reaction. The secondary nuclei were then aggregated further at elevated temperatures, resulting in colloidal particles which exhibited a nearly monodisperse size distribution. Particle diameters were controlled over a wide size range from 50 nm to 1 μm. Mie simulations of the experiment extinction spectra determined that the volume fraction of the ZnS is 0.66 in an aggregated colloidal particle and the colloidal particle effective refractive index is approximately 2.0 at 590 nm in water. The surface of the colloidal particles was subsequently coated with silica to produce ZnS@silica core-shell particles.

• 한국패류학회지
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• 제29권4호
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• pp.313-323
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• 2013

Gonad development, the reproductive cycle, first sexual maturty and size at 50% of group sexual maturity (the biological minimum size) of Gomphina (Macridiscus) veneriformis were investigated for clams collected from the coastal waters of Donghae City, the East Sea of Korea by histological, and morphometric analysis. Monthly variations of the gonad index showed a pattern similar to that of the reproductive cycle. The reproductive cycle with the gonad developmental stages in female and male G. (M.) veneriformis can be classified into five successive stages: early active stage (December to March), late active stage (March to June), ripe stage (June to July), partially spawned stage (June to August), and spent / inactive stage (September to December). The spawning period continued from June to August, with a peak between July and August when the seawater temperature exceeds $20^{\circ}C$. The percentages of first sexual maturities of female and male clams ranging from 25.1 to 30.0 mm were 56.3% in females and 61.1% in males, and for clams over 30.1 mm shell length, it was 100%. Shell lengths at 50% of group sexual maturity (biological minimum size, $RM_{50}$) were 27.71 mm in females and 26.31 mm in males. Because harvesting clams < 26.31 mm in shell length could potentially cause a drastic reduction in recruitment, a measure indicating a prohibitory fishing size should be taken for adequate fisheries management.

• 수산해양기술연구
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• 제49권4호
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• pp.449-458
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• 2013

This study investigated purplish Washington clam, Saxidomus purpuratus on its gonadal development, reproductive cycle and shell length (age) at 50% female group maturity from January to December 2011 in Jinhae Bay, Korea. This species is dioecious. The gonad index (GI) began to increase in January, reached the maximum value in May and to decrease in June, reached the minimum value in September then to increase slowly in October again. The reproductive cycle of the clams can be divided into five successive stages: the early active stage (Ea, from February to March), the late active stage (La, from January to March and October to December), the ripe stage (R, from January to May), the spawning stage (S, from June to December) and the degenerative and inactive stage (Ia, from January to February and November to December). The spawning periods were from June to December and the main spawning periods were from July to October. The shell length at 50% female group maturity (SL50) was estimated to be 63.6 mm, which can be converted as sexual maturity age of 2.2 year.

• 한국수산과학회지
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• 제37권2호
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• pp.105-115
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• 2004

Growth pattern of the soft clam (Mya arenaria oonogei) was estimated based on samples collected from the Yeongsan River estuary on the southwest coast of Korea between August 1996 and September 1997. Mean density of the clam during study period was $55\;ind./m^2$ and varied monthly from 281 to $8\;ind./m^2.$ The clams from the study area ranged in age from one year to seven years, with shell lengths between 40.4 mm and 104.1 mm and biomass between 8.4 and 152.3 g in total wet weight. The spawing season was estimated to occur between September and October based upon a reduced fatness index, an indication of spawning, during these months. Burial depths increased with growth of the clams and most were found buried between 10 and 20 cm in the sediments. Significant relationships were found between shell length and shell height (SH), total wet weight, (TWt), meat wet weight (MWt), meat dry weight (DWt), ash free dry weight (AFDW) and burial depth. The von Bertalanffy growth equations of the clams were $L_t(mm)=138.98(1-e^{-0.1325(t+0.8853)})\;and\;W_t\;(gTWt)=325.93\;(1-e^{0.1325(t+0.8853)})^{2.6982}.$ These equations suggest that in their first year the clams should reach 31 mm in length with a biomass of 5.7 g in total wet weight.

• 한국양식학회지
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• 제17권3호
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• pp.197-208
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• 2004

백합과에 속하는 유용이매패류인 살조개, Protothaca jedoensis, 바지락, Rudirapes philippinam, 개조개, Saxidomus punuratus, 가무락조개, Cyciina sinensis, 백합, Meretrix lusoria 등 5종간의 패각 외부와 내부의 형태형질을 비교 조사하여 계통유연관계를 밝히고자 하였다. 계측형질중에서 주치의 길이만 패각의 크기와 일치할 뿐, 모든 계측형질의 크기가 패각의 크기순으로 나열되지 않는 점으로 보아, 계측형질은 고유의 종 형태적 특징을 나타낸다고 할 수 있겠다. 교판의 길이는 각장, 각고, 각폭 어느 것으로 비교하든지 종간 지수가 일정하게 나타났으나 다른 계측형질 지수는 일정하게 종간순으로 나타나지 않았다. 살조개와 바지락간의 형태적 유사도는 가장 높게 나타났으며, 살조개와 백합의 형태적 유사도는 낮은 값을 나타내었다. 이는 서식장의 환경적인 영향이 가장 크다고 생각되며, 형태형질의 비교에서 백합이 다소 유사도가 낮게 되는 것은 유전적인 형질에 의해서 영향을 받는다고 사료된다. 살조개를 자원증식을 위한 인공종묘생산을 시도하고자 한다면, 형태적 계통유연관계에서도 가장 근연종으로 보이는 바지락을 중심으로 활용방안을 모색해 보아야 할 것으로 사료된다

• 한국분말재료학회지
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• 제24권1호
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• pp.6-10
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• 2017

This study investigates the main growth mechanism of InP during InP/ZnS reaction of quantum dots (QDs). The size of the InP core, considering a synthesis time of 1-30 min, increased from the initial 2.56 nm to 3.97 nm. As a result of applying the proposed particle growth model, the migration mechanism, with time index 7, was found to be the main reaction. In addition, after the removal of unreacted In and P precursors from bath, further InP growth (of up to 4.19 nm (5%)), was observed when ZnS was added. The full width at half maximum (FWHM) of the synthesized InP/ZnS quantum dots was found to be relatively uniform, measuring about 59 nm. However, kinetic growth mechanism provides limited information for InP / ZnS core shell QDs, because the surface state of InP changes with reaction time. Further study is necessary, in order to clearly determine the kinetic growth mechanism of InP / ZnS core shell QDs.

• 한국패류학회지
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• 제27권2호
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• pp.143-148
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• 2011

연구는 양질의 피조개 수정란 확보와 안정적 종묘생산을 위하여 피조개 모패의 먹이생물로 미세조류 3종 (Isochrysis galbana, Tetraselmis tetrathele, Phaeodactylum tricornutum) 을 단독 또는 혼합 공급하여 먹이생물에 따른 피조개 모패의 비만도, 생식소발달, 성숙유도율 및 생존율을 조사하였다. 사육 45일 경과 후 피조개 모패의 완숙기 출현율, 성숙유도율 및 생존율은 3종의 미세조류를 혼합 공급하거나 T. tetrathele를 단독공급한 실험구에서 가장 높았다.

• 수산해양기술연구
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• 제36권3호
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• pp.210-221
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• 2000

완도연안의 비단가리비 개체군을 대상으로 자원생태학적 특성을 규명하기 위해 1998년 11월부터 1999년 10월까지 서식환경 및 밀도조사를 하였고, 패각에 나타난 윤문을 이용하여 연령과 성장을 구명하고, 생식소 난성숙비, 숙도지수의 변화, 포란수 측정 등으로부터 성숙과 산란에 대하여 조사하였다. 1. 수온 및 비중의 범위는 7.6∼25.9$^{\circ}C$, 1.0188∼l.0260였고 DO와 pH는 각각 6.48∼9.50ppm, 8.17∼8.80의 범위였다. 2. 저질상태에 따른 서식밀도는 암반과 자갈에서 28.83 마리/100㎡의 가장 높은 서식밀도를 보였고, 전체의 82,4%가 서식하였다. 3. 각장 (SL)과 각고 (SH)와의 관계는 SH=1.021SL+2.211 (R$^2$= 0.989), 각장과 전중량(TW)의 관계는 TW=$0.0003SL^{2.837}$ (R$^2$= 0.980)였다. 4. von Bertalanffy 성장식의 매개변수 추정치를 보면 이론적 최대각고($SH_{\infty}$)는 117.4mm, 성장계수 (K)는 0.612/yr, 각고가 0일 때의 이론적인 연령 ($t_{0}$)는 -0.017세였다. 5. 50% 군성숙연령은 0.21세로 이 때의 군성숙 각고는 18.3mm였다. 산란기는 6∼7월과 10월 연 2회 추정되었으며, 포란수 (Fc)에 대한 각장 (SL) 및 생식소중량 (GW)의 관계는 Fc = $697.03SL^{2.683}$ (R$^2$= 0.984), Fc =10,076,090GW + 15,608,781 (R$^2$= 0.990)로 나타났다.