• 한국산림과학회지
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• 제96권2호
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• pp.138-144
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• 2007

This study was undertaken to compare the biomass of Abies koreana growing at two sites. A $10{\times}10m$ plot was established in each site of a natural stand in Mt. Jiri and a plantation in Gyeongsan nursery. Five trees of A. koreana were randomly selected in each site. The following traits were investigated from each tree : height, basal diameter, age, weight of stem, branches, and needles as above-ground traits and weight of total roots, horizontal roots, and vertical roots as below-ground traits. In Gyeongsan nursery, age of sample trees was negatively correlated with both height and weight of total stem, while height was highly correlated with weight of horizontal roots. There was high correlation between the basal diameter and weight of total stem, and between the basal diameter and weight of roots. In Mt. Jiri stand, most of the above-ground traits except age were significantly correlated with the below-ground traits. The linear regression equation between the cross section area of base (X) and the weight of total stem (Y) in Gyeongsan nursery was Y=12.66X-12.92, and correlation was significant ($R^2=0.89$). The linear regression equation between the cross section area of base(X) and the weight of total branches (Y) in Mt. Jiri stand was Y=25.51X+6.00, and correlation was highly significant ($R^2=1.0$).

• Asian-Australasian Journal of Animal Sciences
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• 제15권6호
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• pp.872-877
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• 2002

Two experiments were conducted to determine the effects of reducing particle size of corn from 1,000 to 500 ${\mu}m$ in simple and complex diets for nursery pigs and broiler chicks. In Exp 1., 192 nursery pigs were used in a 24 d growth assay. Treatments were: 1) 1,000 ${\mu}m$ corn in a simple diet; 2) 500 ${\mu}m$ corn in a simple diet; 3) 1,000 ${\mu}m$ corn in a complex diet; and 4) 500 ${\mu}m$ corn in a complex diet. Overall, pigs fed complex diets had 9% greater ADG (p<0.005) and 5% greater gain/feed (p<0.01) compared to pigs fed simple diets. Also, pigs fed the 500 ${\mu}m$ treatments had 3% better overall gain/feed than those fed the 1,000 ${\mu}m$ treatments (p<0.007). At d 9, apparent digestibilities of DM, N and GE were greater for complex diets and diets with smaller particle size (p<0.02). At d 23, there were no differences in nutrient digestibility resulting from diet complexity, but pigs fed diets with corn ground to 500 ${\mu}m$ had greater digestibility of DM (p<0.02) and GE (p<0.003) than pigs fed diets with corn ground to 1,000 ${\mu}m$. A second experiment was designed to determine if four days old broiler chicks were an acceptable model for predicting the effects of feed processing procedures on nursery pigs. Chicks fed complex diets had 3% greater gain/feed than chicks fed simple diets (p<0.001). Rate of gain and feed intake were improved by 3 and 2%, respectively, for chicks fed crumbled diets (p<0.03). However, there were several significant interactions among the main effects. For instance, crumbling did not affect gain/feed in chicks fed complex diets, but rate of gain and feed intake were increased by 7 and 6%, respectively, when simple diets were crumbled (diet complexity${\times}$diet form, p<0.001). Also, gain/feed of chicks was improved by 3% when particle size was reduced in meal diets, but not affected in chicks fed crumbles (diet form${\times}$particle size, p<0.005). Thus, our data suggested that reduction of particle size of corn was important for simple and complex diets and that a complex diet with 1,000 ${\mu}m$ corn gave no better performance than a simple diet with 500 ${\mu}m$ corn.

• 한국수산과학회지
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• 제36권2호
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• pp.120-128
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• 2003

Fishes were caught by a set net in the coastal waters off Yosu, Korea from April to October, 2001, and seasonal variation of abundance and species composition were studied. Fifty two species were identified as fish $(89\%)\;cephalopods\;(10\%)\;and\;crustaeans\;(1\%).$ Of the fishes Engraulis japonicus, Trachurus japonicus and Trichiurus lepturus were dominant species representing $64.1\%$ in total number of individuals. The number of species was high in spring and low in summer; number of individuals was high in spring and low in autumn. The diversity index (H') was 0.4-0.7 The abundance and species composition fluctuated seasonally. Occurrence of the various stages of fishes indicated that Scombia japonicus, T. japonicus and E japonicus utilized in the area as spawning ground, Conger myriaster larvae, Ammodytes personatus and Seriola quinqueradiata as nursery ground, and T. lepturus and Ilisha elongata as spawning and nursery grounds.

• 한국양식학회지
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• 제20권2호
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• pp.81-84
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• 2007

We studied two research items that can be undetermined issues in the artificial seed production of the Japanese scallops, Patinopecten yessoensis, batch-specific quality of the reproductive outputs and nursery acclimation, in the embayed waters of Yangyang, Gangwon, Korea. The first batch of the spawner showed better results in terms of survival, growth, and resistance against parasitic ciliate infection over the second batch that was obtained in 5 days after first batch from the same spawner. The early attached spats directly placed in the farming ground (the unacclimated) were resistant against the water current of the open environment, by showing survival of about 80% for a month, a normal survival compared with other results. However, the spat survival during the nursery acclimation was significantly lowered in comparison with that in the unacclimated condition (P<0.01). We discussed the research results of the two items, particularly focusing on their availability for mass seed production for aquaculture in the Korean coastal waters of the East Sea (Sea of Japan).

• 한국산림과학회지
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• 제32권1호
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• pp.1-8
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• 1976

잣나무 2-1묘(苗)와 방크스소나무 1-1묘(苗)의 생장(生長)에 미치는 밀도효과(密度効果)를 보기 위하여 광릉묘포(光陵苗圃)에서 잣나무의 경우는 $m^2$당 36본에서 324본까지 식재(植栽)하였으며 방크스소나무는 25본에서 169본까지 식재(植栽) 하였다. 실험결과(實驗結果) 묘고(苗高), 근원경(根元經), 건중량(乾重量) 및 규격묘(規格苗) 생산(生産)에 뚜렷한 효과(効果)를 보았다. 잣나무 2-1묘(苗)는 밀식(密植)시킬수록 수고생장(樹高生長)은 증대되고, 방크스소나무는 식재밀도구간(植栽密度區間)에 차이(差異)가 없었다. 잣나무와 방크스소나무는 밀식시킬수록 근원경(根元經) 생장(生長)은 감소되는 경향이 있으나 후자(後者)가 급격히 감소하고 있다. 잣나무의 평균목(平均木) 건중량(乾重量)은 밀식(密植)시킬수록 감소율은 낮으나 방크스소나무는 높다. 밀식(密植)으로 인해 일반적으로 T/R율(率)의 값은 증대되나 식재밀도구간(植栽密度區間)에 큰 차이(差異)가 나타나지 않고 있다. 평균목(平均木)의 잎 뿌리와 줄기의 건중량은 밀식(密植)시킬수록 감소되고 있으나 방크스소나무가 잣나무 보다 감소율이 높다. 그리고 잣나무의 경우는 줄기의 건중량(乾重量)은 밀식구(密植區)와 소식구간(疎植區間)에 차(差)가 적다. 밀식(密植)으로 나타나는 잣나무의 세장성(細長性) 보다는 방크스소나무의 세장성(細長性)이 더욱 높게 나타나고 있으나 밀식(密植)시킬수록 전체적인 물질생산량(物質生産量)은 증대되리라 생각 된다. 이상의 생장특성(生長特性)으로보아 잣나무의 이식상(移植床)을 만들때와 조림(造林)은 밀식(密植)시키도록 하고 방크스소나무는 소식(疎植)함이 효과(効果)적일것으로 생각 된다. 잣나무 2-1묘(苗)의 규격(規格)은 간장(幹長) 18cm 근원경(根元經)은 4mm로 개정(改正)시키고 $m^2$당 이식본수(移植本數)는 묘포비옥도(苗圃肥沃度)에 따라 160~200본(本)으로 함이 적합하리라 생각되며, 방크스소나무 1-1묘(苗)의 규격(規格)은 간장(幹長) 25cm 근원경(根元經) 6mm가 적합하며 $m^2$당 이식본수(移植本數)는 묘포비옥도(苗圃肥沃度)에 따라 100-120본(本)이 적합할 것이다.

• 한국농공학회:학술대회논문집
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• 한국농공학회 2005년도 학술발표논문집
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• pp.690-694
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• 2005

It is necessary that the construction of submerged breakwater could minimize and compensate the negative effect on the marine environment and ecosystem caused by the Saemangeum reclamation. The important merit of this proposal is that the space between Saemangeum embankment and submerged breakwater is expected to become nursery ground for fish and shellfishes. The purpose of this study was investigated hydraulic characteristic of submerged breakwater to investigate the possibility of mitigation in the fisheries ground by hydraulic experiment.

• 한국환경농학회지
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• 제40권2호
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• pp.73-82
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• 2021

BACKGROUND: The successful management of jujube trees depends on maintaining a balance between reproductive and vegetative growth. In general, heading cuts of trunk stimulate rather vegetative growth, but could decrease flower initiation. This study was conducted to establish a heading-back pruning severities at planting in the one year old 'Daeneung' jujube whip nursery tree by investigating vegetative growth and fruit yield. METHODS AND RESULTS: The heading back pruning severity was assigned as 5 different ranges as follow: one bud (TR-10, heading back pruning was 10 cm above the ground), three buds (TR-30), five buds (TR-50), seven buds (TR-70), and nine buds (TR-90) were left of scion. The number of buds on whip trunk was correlated to the central leader length and increment of trunk cross-sectional area, negatively, and to the tree height and canopy volume, positively. The yields in the TR-50 treatment were higher about 2 times than other treatments. The fruit diameter was not significantly different among the treatments. CONCLUSION: These results indicated that the optimum location of heading-back pruning in one year old 'Daeneung' jujube tree was 50 cm above the ground as evaluated by the balance of reproductive and vegetative growth.

• 한국수산과학회지
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• 제43권6호
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• pp.751-755
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• 2010

To understand the function of nursery grounds, the seasonal variation of ichthyoplankton was investigated in the East Sea, off Dokdo, from September 2009 to May 2010. The dominant species was Engraulis japonicus (92.7%), which occurred in May and September. The next abundant species was Maurolicus japonicus (5.7%), found in all four seasons. Several rare warm-water species were found in September and November, when the species diversity was higher than in the other two seasons. Several fish species used Dokdo as a nursery ground for a restricted season, while M. japonicus used it in all four seasons.

• 한국수산과학회지
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• 제54권4호
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• pp.498-507
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• 2021

Ichthyoplankton (fish eggs and larvae) were collected seasonally collected from 2017 to 2019 to clarify whether Dokdo serves as a fish spawning and/or nursery ground. Fish eggs were identified and classified into 16 species. The dominant fish egg species were Engraulis japonicus, Maurolicus japonicus, and Parajulis poecilepterus. Fish larvae were identified and classified into 15 species. The dominant fish larvae species were E. japonicus, M. japonicus, and Sebastes owstoni. A cluster analysis similarity percentages revealed two distinct groupings according to sample location (stations) with E. japonicus and M. japonicus as the main group influencers. E. japonicus was the dominant species off Dokdo. The species diversity and abundance peaked in summer. The diversity index, richness index, and evenness index fluctuated seasonally. There were no predominant species variations among the years. Sedentary species such as P. poecilepterus, Semicossyphus reticulatus, and Glyptocephalus stelleri occurred in the inshore stations. E. japonicus, M. japonicus, and Trachipterus trachypterus occurred in the offshore stations. Our results show these species use Dokdo as spawning and nursery grounds.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2009년도 춘계학술대회 논문집
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• pp.73-76
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• 2009

Generally, wind or solar power system is operated as a stand-alone power system, the efficiency of which could be higher by designing wind-solar combined system considering average wind speed and solar radiation of the desert region, Mongolia. This system is designed to generate electricity for power users and pumps the ground water for irrigation using deep well pump. The ground water can be used for farming or forestation where there is no or little irrigation system. In connection with this study, a renewable energy park, Green Eco Energy Park, was developed at about 50km east of Ulaanbaatar. 3 sets of 10kW wind power generator and 70 kW of solar power module were installed there. The electricity generated from the system is used to on-site office building and deep well pump for ground water pumping. A 10kW stand-alone solar pumping system, which has no rechargeable battery system, is installed to pump the ground water with the amount of generated power. The ground water is stored in 3 artificial ponds and then it is used for raising nursery tree and farming. The purpose of this study is to provide a possible energy solution to desert regions where there is no or little power system. The system also supply power to ground water pump, and the water can be used for farming and forestation, which will also be a solution of preventing desertification or spreading of desert area.