• Weed & Turfgrass Science
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• 제4권3호
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• pp.262-267
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• 2015

잔디 뗏장의 효율적인 생산과 토양 관리 시스템을 구축하고 재배방법을 개선하기 위한 기초 데이터를 제공하기 위해, 토양환경에 따른 잔디의 생육상태에 대한 연구를 수행 할 필요가 있다. 본 연구는 뗏장 생산의 재배기간에 따른 잔디의 생육과 토양 화학적 특성을 조사하기 위해 뗏장 재배기간이 1년, 10년, 20년, 그리고 30년 된 지역을 각각 조사하였다. 재배기간이 장기화됨에 따라, 토양 용적밀도는 증가하였고, 공극률과 기상은 감소하였다. pH는 30년 동안 재배된 곳에서 가장 높았고, 전질소와 유기물의 함량은 1년 동안 재배된 토양에서 가장 높았다. 결과적으로, 토양 화학적 특성은 1년 재배된 토양에서보다 계속적인 재배 토양에서 악화되었다. 잔디의 재배기간이 길어짐에 따라 지상부와 지하부의 생육이 감소하였다. 그러므로 계속적인 잔디 뗏장 생산 재배로 인한 토양 악화가 잔디의 품질과 생장을 감소시키므로, 10년 이상 연작된 지역에서는 토양 갱신을 통해 잔디생육을 향상시켜야 한다.

• 한국수산과학회지
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• 제47권6호
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• pp.935-944
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• 2014

To elucidate the variation of species composition, biomass and size distribution of fishery resource in the Uljin marine ranching area was investigated at the 4 stations from 2009 to 2010 based on the dredge sampling. During the survey period, a total of 41 fishery resource species were sampled with a mean density of $2,554,633\;ind./km^2$ and mean biomass was $32,946kg/km^2$. A total 36 fishery resource species were sampled with a mean density of $3,198,793\;ind./km^2$ and mean biomass $41,177kg/km^2$ in 2009 and it were sampled a total 31 species, mean $1,910,473kg/km^2$ and $24,716kg/km^2$ in 2010. The major individual-dominant species, occupying over 1% of total individuals, were Gomphina veneriformis (2,491,818 ind., 82.2%), Umbonium costatum (221,973 ind., 8.7%), Mactra chinensis (49,879 ind., 2.0%), Glossaulax didyma hayashii (49,879 ind., 1.9%), Blepharipoda liberate (37,714 ind., 1.5%) and Paguridae spp. (27,266 ind., 1.1%). The major biomass-dominant species, occupying over 1% of total biomass, were G. veneriformis (25,124 kg, 76.3%), G. didyma hayashii (2,596 kg, 7.9%), M. chinensis (2,024 kg, 6.1%), Ovalipes punctatus (921 kg, 2.8%) and Glossaulax didyma didyma (567 kg, 1.7%). From the cluster analysis based on Bray-Curtis similarity matrix of fourth root transformed data of species number and individuals was divided into 2 different groups of the fishery resource community (Group A-St.1, Group B-Sts. 2, 3, 4). The 2009 and 2010 mean Shell length (mm) of G. veneriformis was 37.73 mm, 29.76 mm and M. chinensis was 62.03 mm, 44.94 mm, respectively.

• 아시안잔디학회지
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• 제18권1호
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• pp.1-13
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• 2004

한지형잔디의 활용이 늘어나고 있는 시점에서 우리의 기후에 알맞은 한지형잔디를 선정하여 골프코스 및 경기장에 활용하기 위하여 2003년 3월 인천광역시 운서동에 잔디 시험 포지를 조성하여 시험을 하였다. 1. 켄터키 블루그래스 단용구와 퍼레니얼 라이그래스 혼용구를 시험한 결과 켄터키 블루그래스 단용구에서는 Midnight 품종이 가장 좋은 잔디 품질을 나타내고 있었으며, 잔디의 색상 면에서도 진한 녹색을 유지하여 잔디의 시각적 품질평가가 매우 우수하게 나타났다. 2. 그 다음으로 좋은 평가를 받은 잔디품종은 North Star 품종으로 Midnight와 유사한 색상을 띠고 있는 품종으로서 Midnight와의 혼용하여 활용하면 좋은 결과를 얻을 수 있다고 생각되며, 또한 좋은 품종 특성은 염분에 저항성이 강하다는 점으로 수질이 악화되어 가고 있는 현실에서는 유리한 품종으로 판단된다. 3. 퍼레니얼 라이그래스와의 혼용으로는 Brilliant, Midnight 두 품종과 퍼레니얼 라이그래스 2가지 품종을 혼용하여 시험하였다. 그중 가장 좋은 결과를 보여준 품종든 Midnight + Brightstar SLT를 혼용으고서 우수한 잔디 품질을 유지하였다. 그다음이 Midnight＋BrightstarII 혼용구로 Midnight이 지니고 있는 우수한 잔디의 특성에 의한 영향이 컸던 것으로 판단된다. 4. 시험결과에 의하면 켄터키 블루그래스 단용구에 비해 켄터키 블루그래스와 퍼레니얼 라이그래스 혼용구의 시각적 품질과 시각적 색상이 우수한 것으로 미루어 골프장 teeing ground와 fairway를 조성할 경우는 잔디를 혼용하는 것이 더 적합할 것으로 판단된다.

• 한국응용곤충학회지
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• 제31권4호
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• pp.396-415
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• 1992

약용작물에 대한 기생선충의 분포상황 및 선충에 의한 약용작물의 피해상황, 작부체계에 따른 선충의 기생정도 등을 구명하기 위하여 시험한 결과는 다음과 같다. 기생식물별 선충기생상황은 작약의 25개 작물중에서 총 10과 15속 25종의 식물기생선충이 검출되었으며, 가장 밀도가 높은 것은 Meloidogyne hapla였고, 다음이 Tylenchus sp., Ditylenchus dipsaci., Aphelenchoides sp., Tylenchorhynchus claytoni등의 순으로 많이 검출되었는데, 바이러스 매개충인 Xiphinema sp. 과 Trichodorus sp. 도 검출되어 바이러스 감염도 우려되었다. 선충 기생에 의한 피해조사에서 작약, 방풍, 백지, 내궁, 인상, 당귀, 시호가 Meloidogyne hapla, M. incognita에 의해 심하게 기생당하였으며, 포장감염율은 54.5~88%였고 재배년수가 경과 할수록 선충기생에 의한 뿌리혹(Gall), 난낭(Egg mass), 유충(2nd larvae)의 밀도가 높았는데, 지하부 뿌리의 분지수는 뿌리혹선충의 기생이 많을 수록 높았다. 뿌리혹선충 기생에 의한 약용작물별 감수율을 조사한 결과 건전주의 근중에 비해 당귀에서는 57.8, 작약은 49.1, 시호는 27.9%의 감수율을 보였으며, 피해도는 23.2~88%로 작물별 차이가 컸고, 감염된 포장에서는 피해가 컸으며, 뿌리혹선충 유충의 밀도는 토양 300g당 50~1890마리로 밀도 범위가 컸다. 작약포장에서 작부체계에 따른 선충증식정도를 조사한 결과 논포장에서 벼재배후 작약재배나, 밭에서 참깨재배후 작약재배한 것이 고추나 작약연속 재배한 포장보다 선충의 밀도가 훨씬 낮았다.

• The Korean Journal of Ecology
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• 제21권5_3호
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• pp.649-663
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• 1998

The clarify the ecological properties, and to predict change of understory vegetation of mt. Nam Park, population dynamics and interspecific competition of D. smilacinum and D. viridescens, which grow in understory of deciduous broad-leaved forest and pseudo-annuals, were studied from May 20 to May 30 1998. The depth of litter layer, soil moisture content, soil organic matter and soil texture were surveyed in 18 populations (15 D. smilacinum populations and 3 D. viridescens populations). Mean litter layer of d. smilacimum population was thinner than that of D. viridescens populations). Mean litter layer of D. smilacnum population was thinner than that of D. viridescens population. The contents of soil moisture and organic matter of D. smilacinum population were lower than that of D. viridescens population. The D. smilacinum growed in broad range of soil texture but D. viridescens in loamy soil. Because D. smilacinum could tolerate more broad range of soil moisture and soil texture than D. viridescens, the former covered the herb layer in earlier stage and the latter introduced in later stage when rhizome could grow easily. The numbers of individual in two marginal parts were smaller than that in center in same D. smilacinum patch. And the total numbers of individuals grown in (10 ${\times}$ 10)cm were from 0 to 12. The rhizome (subterranean runner) weight, rhizome length, root weight, shoot weight, lea weight and leaf number per subquadrat (cell) increased along the number of individual, that is, increased from marginal part to center. But rhizome weight and rhizome length per individual were vice versa. Therefore, the individuals in marginal part reproduced longer and stronger asexual propagules than that in center. The distribution pattern of D. smilacinum was contageous and that of D. viridescens was random or regular. Therefore, population growth of former was independent on density and that of latter was dependent on density. The distributions of size-class showed normal curves in two population, but the curves based on data of total dry weight showed positive skewness and those of leaf number showed negative skewness The correlation coefficient (CC) values between the properties of each organ were high in two population and significant at 0.1% level. The CC values of D. viridescens were higher of the two. Therefore, the former allocated the energy to each organ stable. The rhizome depth of d. viridescens was 2 times deeper than that of D. smilacinum. And rhizome length and weight of D. viridescens were longer (2 times) or heavier (4 times) than those of D. smilacinum. The patch size of D. viridescens increased 60 cm per year and that of D. smilacinum 30 cm. On this results, the intrinsic increase velocity of d. viridescens patch was 2 times faster than that of d. smilacinum, therefore, on the competition, the former had an advantage over D. smilacinum. The reason why d. viridescens defeated D. smilacinum resulted from that the leaf area of former was 4 times broader than that of latter. in Mt. Nam Park, it was thought that two disporum Population would change with the 3 thpes of environmental change as followings. First, no human impact and increase of soil moisture content resulted in increase of D. viridescens population. Second, mild human impact and similar condition of soil moisture content resulted in slow increase or no changes of D. smilacinum and d. viridescens population. Third, severe human impact and dry condition resulted in decrease or vanishment of two disporum populations.

• 한국환경농학회지
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• 제22권1호
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• pp.60-64
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• 2003

양액재배용 거어베라 우량묘를 생산하기 위한 기초연구로 플러그셀 크기 및 용토가 묘생장에 미치는 영향을 조사하였다. 용토의 물리성을 측정한 결과 가비중, 진비중 및 공극율은 퍼얼라이트에서 가장 높게 나타났으며 수분보유량은 코코피트에서 가장 높게 측정되었다. 162, 128, 72, 50구 플러그셀트레리별로 퍼얼라이트 코코피트 그리고 퍼얼라이트+코코피트(1:1)을 채우고 60일간 육묘하여 묘의 생육을 조사하였다. 묘의 엽수는 128구 코코피트 처리에서 가장 많았으며 엽면적은 50구 코코피트 처리에서 높게 나타났다. 신초와 뿌리의 생체중 및 건물중 그리고 엽록소 함량은 퍼얼라이트+코코피트 처리에서 높게 측정되었다. 플러그 셀 크기가 클수록 유묘 생장에 효과적이었으며 퍼얼라이트 단용 보다는 코코피트와의 혼용 용토에서 유묘 생육이 가장 양호하였다.

• Smart Structures and Systems
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• 제9권3호
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• pp.231-251
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• 2012

The stochastic optimal control for a piezoelectric spherically symmetric shell subjected to stochastic boundary perturbations is constructed, analyzed and evaluated. The stochastic optimal control problem on the boundary stress output reduction of the piezoelectric shell subjected to stochastic boundary displacement perturbations is presented. The electric potential integral as a function of displacement is obtained to convert the differential equations for the piezoelectric shell with electrical and mechanical coupling into the equation only for displacement. The displacement transformation is constructed to convert the stochastic boundary conditions into homogeneous ones, and the transformed displacement is expanded in space to convert further the partial differential equation for displacement into ordinary differential equations by using the Galerkin method. Then the stochastic optimal control problem of the piezoelectric shell in partial differential equations is transformed into that of the multi-degree-of-freedom system. The optimal control law for electric potential is determined according to the stochastic dynamical programming principle. The frequency-response function matrix, power spectral density matrix and correlation function matrix of the controlled system response are derived based on the theory of random vibration. The expressions of mean-square stress, displacement and electric potential of the controlled piezoelectric shell are finally obtained to evaluate the control effectiveness. Numerical results are given to illustrate the high relative reduction in the root-mean-square boundary stress of the piezoelectric shell subjected to stochastic boundary displacement perturbations by the optimal electric potential control.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2016년도 제50회 동계 정기학술대회 초록집
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• pp.217-217
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• 2016

The amorphous InGaZnO (a-IGZO) is widely accepted as a promising channel material for thin-film transistor (TFT) applications owing to their outstanding electrical properties [1, 2]. However, a-IGZO TFTs have still suffered from their bias instability with illumination [1-4]. Up to now, many researchers have studied the sub-gap density of states (DOS) as the root cause of instability. It is well known that defect states can influence on the performances and stabilities of a-IGZO TFTs. The defects states should be closely related with the deposition condition, including sputtering power, and pressure. Nevertheless, it has not been reported how these defects are created during conventional RF magnetron sputtering. In general, during conventional RF magnetron sputtering process, negative oxygen ions (NOIs) can be generated by electron attachment in oxygen atom near target surface and then accelerated up to few hundreds eV by a self-bias; at this time, the high energy bombardment of NOIs induce defects in oxide thin films. Recently, we have reported that the properties of IGZO thin films are strongly related with effects of NOIs which are generated during the sputtering process [5]. From our previous results, the electrical characteristics and the chemical bonding states of a-IGZO thin films were depended with the bombardment energy of NOIs. And also, we suggest that the deep sub-gap states in a-IGZO as well as thin film properties would be influenced by the bombardment of high energetic NOIs during the sputtering process.In this study, we will introduce our novel technology named as Magnetic Field Shielded Sputtering (MFSS) process to prevent the NOIs bombardment effects and present how much to be improved the properties of a-IGZO thin film by this new deposition method. We deposited a-IGZO thin films by MFSS on SiO2/p-Si and glass substrate at various process conditions, after which we investigated the morphology, optical and electrical properties of the a-IGZO thin films.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2015년도 제49회 하계 정기학술대회 초록집
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• pp.160-160
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• 2015

InGaZnO (IGZO) thin-film transistors (TFTs) are very promising due to their potential use in high performance display backplane [1]. However, the stability of IGZO TFTs under the various stresses has been issued for the practical IGZO applications [2]. Up to now, many researchers have studied to understand the sub-gap density of states (DOS) as the root cause of instability [3]. Nomura et al. reported that these deep defects are located in the surface layer of the IGZO channel [4]. Also, Kim et al. reported that the interfacial traps can be affected by different RF-power during RF magnetron sputtering process [5]. It is well known that these trap states can influence on the performances and stabilities of IGZO TFTs. Nevertheless, it has not been reported how these defect states are created during conventional RF magnetron sputtering. In general, during conventional RF magnetron sputtering process, negative oxygen ions (NOI) can be generated by electron attachment in oxygen atom near target surface and accelerated up to few hundreds eV by self-bias of RF magnetron sputter; the high energy bombardment of NOIs generates bulk defects in oxide thin films [6-10] and can change the defect states of IGZO thin film. In this study, we have confirmed that the NOIs accelerated by the self-bias were one of the dominant causes of instability in IGZO TFTs when the channel layer was deposited by conventional RF magnetron sputtering system. Finally, we will introduce our novel technology named as Magnetic Field Shielded Sputtering (MFSS) process [9-10] to eliminate the NOI bombardment effects and present how much to be improved the instability of IGZO TFTs by this new deposition method.

• 대한치과의사협회지
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• 제47권8호
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• pp.479-486
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• 2009

Purpose: The aim of this study was to show the clinical results of combination of Nd-YAP (1340nm) laser therapy with conventional endodontic and periodontal treatment. Materials and Methods: Four patients with chronic advanced periodontitis and endodontic infection were treated with conventional treatment and Nd-YAP laser therapy. Occlusal adjustment and splinting were done for stabilization of the teeth with severe horizontal and vertical mobility. The protocol for periodontal treatment was followed as scaling and root planing, pocket irrigation with 3% $H_2O_2$ and exposure of Nd-YAP laser using 320${\mu}m$ optical fiber with 160mJ/pluse, 30Hz. The other protocol for endodontic treatment was followed as access opening, canal preparation by hand and rotary instrument, canal filling, and exposure of Nd-YAP laser using 200${\mu}m$ optical fiber with 200mJ/pluse, 10Hz and 180mJ/pluse, 5Hz which were used respectively for disinfection and canal filling. The assessments of probing depth, mobility, and radiography were made prior to and after treatment. Result: All of these four clinical cases showed good healing of periodontium, which presented decrease of mobility and pocket depth, and increase of bone regeneration and bone density on the radiography. Conclusion: The bactericidal effect of Nd-YAP laser would provide benefits for improving clinical results that are obtained from conventional therapy.