• Journal of the Korean Geotechnical Society
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• v.18 no.2
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• pp.75-86
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• 2002

This paper presents sedimentation and consolidation characteristics of dredged soils mixed with sand materials through the self-weight consolidation tests adopting stepwise filling method. After completely throwing away dredged soils daily by flour kinds of S-C, which is the quantity of sand contained, results fi:om laboratory tests are compared with those from a new method using hyperbolic, which considers stage settling and consolidating characteristics, and those from the existing analyzing method. Liquid limit up to 65% had a large effect on consistency properties. Assuming that the settlement occurred only by clay content of dredged soils, it is shown that the clay void ratio is less than 2 and 4 respectively in case S-C is 0% and 50%. In the applied hyperbolic method, reinitialized curve has a linear behavior of a coefficient of correlation of almost 1, and the coefficient of slope and intercept except fur the specimen with the height of 10cm and 20cm had a tendency to fellow exponent function and a shape of zone settling and dispersing settling. The results computed by the applied hyperbolic method rather than the existing analyzing method coincide with those of laboratory tests. It is shown that the former is more suitable than the latter for the area considering the influence, of sand materials.

• Geophysics and Geophysical Exploration
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• v.20 no.3
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• pp.176-184
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• 2017

To interpret the seismic image precisely, random noises should be suppressed and the continuity of the image should be enhanced by using the appropriate smoothing techniques. Structure-Oriented Filter-Edge Preserving (SOF-EP) technique is one of the methods, that have been actively researched and used until now, to efficiently smooth seismic data while preserving the continuity of signal. This technique is based on the principle that diffusion occurs from large amplitude to small one. In a continuous structure such as a horizontal layer, diffusion or smoothing is operated along the layer, thereby increasing the continuity of layers and eliminating random noise. In addition, diffusion or smoothing across boundaries at discontinuous structures such as faults can be avoided by employing the continuity decision factor. Accordingly, the precision of the smoothing technique can be improved. However, in the case of the structure-oriented semblance technique, which has been used to calculate the continuity factor, it takes lots of time depending on the size of the filter and data. In this study, we first implemented the SOF-EP method and confirmed its effectiveness by applying it step by step to the field data. Next, we proposed and applied the corner response method which can efficiently calculate the continuity decision factor instead of structure-oriented semblance. As a result, we could confirm that the computation time can be reduced by about 6,000 times or more by applying the corner response method.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2017.05a
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• pp.164-164
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• 2017

해양환경 중 많이 사용되는 철강재료들은 그 가혹한 부식환경에 대응하기 위하여 일반적으로 피복 도장방식법이나 음극방식법이 적용되고 있다. 여기서 음극방식법은 선박 및 해양구조물의 해중부 부식에 대해 가장 효과적인 방식법으로 알려져 있다. 한편, 이와 같이 해수 중 철강재에 음극방식을 적용할 경우, 피방식체인 그 강재 표면에 해수 중 용존된 산소의 음극환원 반응이 일어나며 국부적인 알카리 표면 조건을 형성시켜 $Mg(OH)_2$와 $CaCO_3$의 막을 석출시킨다. 이와같이 음극방식 중 형성된 전착물은 방식해야 될 표면적을 감소시켜 방식전류밀도를 감소시키는 효과가 있는 것으로 보고되고 있다. 이렇게 석출된 전착물은 음극표면에 부분적으로 형성되고, 여러 가지 환경 조건 등의 영향을 받아 그 피막의 형성 정도도 가늠하기 어렵기 때문에 음극방식 설계 시 그 정도에 따른 영향을 고려-반영하기가 곤란하다. 또한 이 전착물은 그 형성 메커니즘에 관한 해석이나 강도, 균일한 밀착성, 장기적인 방식효과 및 효율성 등이 아직 충분히 입증되어 있지 않은 실정에 있다. 따라서 본 연구에서는 해수 중 다양한 전착 프로세스에 의해 제작된 전착물의 기간별, 도장코팅 종류별 특성변화를 분석 및 평가하고, 전착물에 의한 희생양극 소모전류 변화 측정 분석을 통해 전착막을 균일하고 치밀하게 형성시키기 위한 최적의 조건을 찾고자 하였다. 또한 석출속도, 밀착성 및 내식특성을 향상시키기 위해 해수 중 기체를 용해시켜 제작한 막의 특성을 분석-평가하였다. 본 연구에 사용된 강 기판은 일반구조용강(KS D 3503, SS400)으로 ${\varnothing}42.7{\times}1,000mm{\times}4.0t$의 형상으로 제작하였다. 인가된 전류밀도는 1, 3 및 $5A/m^2$이고 도장 코팅 종류별 전착 석출물의 형성차이 비교 분석을 위한 실험은 선박 및 해양구조물에 많이 사용되는 Universal Epoxy 도료 2종을 선정하여 진행하였다. 또한 Steel Wire Mesh의 영향을 알아보기 위해 Mesh를 설치하여 실험을 진행하였다. 기간별-도장 종류별 외관관찰, 전착물의 두께 측정, SEM, EDS 및 XRD를 통해 막의 모폴로지, 조성원소 및 결정구조를 분석하였으며, 전착물의 내식성과 내구성을 평가하기 위해 테이핑 테스트(Taping Test) 및 전기화학적 양극분극 시험을 실시하였다. 희생양극 소모율에 대한 전착물의 영향을 확인하기 위해 외부전원을 인가하여 전착 피막을 형성시킨 강 기판에 희생양극을 연결하여 희생양극 소모효율 측정 시험을 진행하였다. 전착물의 석출량은 시간 및 전류밀도의 증가에 따라 비례하여 증가하였으며, 음극전류 인가 시 금속과 용액 계면 사이의 확산층에서 발생한 $OH^-$ 이온으로 인해 금속과 용액 계면 사이 pH가 부분적으로 증가하여 $Mg(OH)_2$ 화합물이 많이 생성되는 것으로 확인되었다. 또한 Mesh의 부착으로 평활하지 않게 형성된 미세한 굴곡구조 및 표면적 증가로 인하여 단계적으로 피복되는데 필요한 시간이 지연되면서 $CaCO_3$에 비해 $Mg(OH)_2$ 화합물이 상대적으로 증가한 것으로 사료된다. $CaCO_3$(Aragonite) 구조는 견고한 피막으로 치밀하고 화학적 친화력이 높아 우수한 밀착성을 보였으며 전착물의 영향으로 양극 전류가 감소하였고, 이로인해 방식전류 절감효과를 얻을 수 있을 것으로 기대된다.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.56 no.2
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• pp.99-106
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• 2011

Here we reported an analyzing result for the relationship between climatic variables and rice(c.v. Odaebyeo and Ilpumbyeo) yield characteristics (including some growth characteristics) based on a long-term observed data at GARES and at KMA for rice and weather, respectively. Most of crop parameters investigated, such as heading date, culm height, panicle number $m^{-2}$, grain number $panicle^{-1}$ ripening rate, 1,000 grain weight and yield were strongly affected by wind velocity and relative humidity, as well as by daily mean air temperature, precipitation, sunshine hours and daily variations in air temperature depending on variety and crop developmental stages. Air velocity and relative humidity had not been studied as climatic variables affecting on the characteristics of rice growth and yield, however, they turned out to affect all the characteristics of rice investigated, especially ripening rate and yield, as much as any other climatic variables in this study. Air velocity appeared to affect highly the culm height and yield of Odaebyeo and ilpumbyeo. Relative humidity appeared to affect highly grain number and ripening rate of Odaebyeo and yield of Ilpumbyeo. Consequently Rice yield revealed to increase in the climatic conditions of high air velocity and low relative humidity.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2003.04a
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• pp.143-143
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• 2003

본 연구는 항산화효소의 효율적 생산을 위한 적절한 수확시기의 결정 및 산업적 가치를 검토하고자, 제주도에 자생하는 문주란 (Crinum asiaticum var. japonicum)에서 항산화효소 (SOD, peroxidase, catalase, APX) 활성과 isoenzyme 패턴의 계절적 변화양상을 조사하였다. SOD isoenzyme 패턴을 전기영동으로 살펴보면, 전체적으로 7개의 isoenzyme이 검출되었으며, 여름철과 겨울철에 있어서 뚜렷한 차이가 없을 뿐 아니라 일변화에 있어서도 큰 차이를 보이지 않았다. 그리고 이들 isoenzyme은 $H_2O$$_2$와 KCN에 의한 선택적 저해로부터 1개의 Mn-SOD와 6개의 CuZn-SOD로 구분할 수 있었다. Catalase는 단일밴드로 나타났으며, 여름철이 겨울철에 비해 높은 활성을 보였다. Peroxidase는 전체적으로 4개의 isoenzyme이 검출되었다. 이 중 peroxidase 1은 효소활성에는 차이가 있지만 여름철과 겨울철에 모두 검출되었으며, 3개의 isoenzyme (peroxidase 2-4)은 겨울철에만 특이적으로 검출되는 것으로 나타났다. 그리고 여름철에는 낮시간에 다소 높은 활성을 보였으며, 겨울철에는 낮시간보다는 새벽과 밤에 높은 활성을 보였다. APX는 8개의 isoenzyme이 검출되었으며, 여름철과 겨울철에 있어서 뚜렷한 차이를 보이지 않았다. 이상의 결과를 종합해보았을 때 SOD, catalase, peroxidase, APX 등 항산화효소의 산업적 생산을 위한 채취는 수확량을 감안하였을때 여름철이 적정 채취시기로 보인다. 그리고 문주란의 catalase와 peroxidase는 SOD나 APX는 달리 단일 밴드 또는 주요 밴드가 있고 높은 활성을 보여 정제시 유리하게 작용할 것으로 보인다. prospects will be also discussed.behaviors to ferromagnetic behavior was observed. Tunneling barrier called "decay length for tunneling" for the films having the thickness of Co layer from 1.4 to 1.6 nm was measured to be ranged from 0.004 to 0.021 ${\AA}$$\^$-1/.문에 기업간 관계를 연구하는 측면에서는 탐험적 연구성격이 강하다. 더 나아가 본 산업의 주된 연구가 질적이고 기업내부만을 연구했던 것에 비교하면 시초적이라고 할 수 있다. 또한 관계마케팅, CRM 등의 이론적 배경이 되고 있는 신뢰와 결속의 중요성이 재확인하는 결과도 의의라고 할 수 있다. 그리고 신뢰는 양사 간의 상호관계에서 조성될 수 있는 특성을 가진 반면, 결속은 계약관계 초기단계에서 성문화하고 규정화 할 수 있는 변수의 성격이 강하다고 할 수가 있다. 본 연구는 복잡한 기업간 관계를 지나치게 협력적 측면에서만 규명했기 때문에 많은 측면을 간과할 가능성이 있다. 또한 방법론적으로 일방향의 시각만을 고려했고, 횡단적 조사를 통하고 국내의 한 서비스제공업체와 관련이 있는 컨텐츠 공급파트너만의 시각을 검증했기 때문에 해석에서 유의할 필요가 있다. 또한 타당성확보 노력을 기하였지만 측정도구 면에서 엄격한 개발과정을 준수하지는 못했다. 향후에는 모바일 컨텐츠 파트너의 기업의 특성을 조사하여 관계성 변수와의 상호관련연구를 진행할 필요가 있다. 관계기간, 의존성, 거래처의 단/복수여부, 서비스 범주 등의 제반 변수를 고려하여 이러한 변수가 양사와의 관계성 변수에 어떤 영향이 있는가를 검증할 필요가 있다. 또한 신뢰, 결속 등 다차원의 개념

• Journal of Industrial Convergence
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• v.20 no.8
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• pp.77-84
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• 2022

This study aims to present a method for implementing a decision support system that can be used for selecting emerging technologies by applying a machine learning-based automatic classification technique. To conduct the research, the architecture of the entire system was built and detailed research steps were conducted. First, emerging technology candidate items were selected and trend data was automatically generated using a big data system. After defining the conceptual model and pattern classification structure of technological development, an efficient machine learning method was presented through an automatic classification experiment. Finally, the analysis results of the system were interpreted and methods for utilization were derived. In a DTW-kNN-based classification experiment that combines the Dynamic Time Warping(DTW) method and the k-Nearest Neighbors(kNN) classification model proposed in this study, the identification performance was up to 87.7%, and particularly in the 'eventual' section where the trend highly fluctuates, the maximum performance difference was 39.4% points compared to the Euclidean Distance(ED) algorithm. In addition, through the analysis results presented by the system, it was confirmed that this decision support system can be effectively utilized in the process of automatically classifying and filtering by type with a large amount of trend data.

• Journal of the Korean Magnetics Society
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• v.4 no.1
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• pp.12-19
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• 1994

The crystallization behavior of the amorphous $Fe_{73.5}Cu_{1}Nb_{3}Si_{16.5}B_{6}$ alloy with isothermal annealing at $552^{\circ}C$ was studied by $M\"{o}ssbauer$ spectroscopy. The amorphous phase was revealed to coexist together with $Do_{3}-FeSi$ nanocrystalline and Cu-duster in annealed alloys by $M\"{o}ssbauer$ spectrum analysis. At the early stage of crystallization, Si content of FeSi is high due to the creation of Cu-cluster, and decreases with annealing until 60 minutes, which results in the increase in the mean hyperfine field of FeSi, and thereafter keeps constant. After 60 minutes, the decrease in the mean hyperfine field of the residual armrphous, in spite of a slight change in the volume fraction of the FeSi and the residual armrphous, is caused by the increase in the content of Nb and B in residual amorphous phase. Both directions of the hyperfine field, those of the FeSi and the residual amorphous, become randomly oriented in about 60 minutes. For FeSi and Cu-duster, the Avrami exponents are 0.51 and O.65, the activation energies are 2.35 eV and 2.44 eV, and the incubation times are 2.4 minutes and 0.8 minutes respectively. Earlier formation of Cu-duster than that of FeSi is coincidence with the fact that Cu atom promotes the nucleation of the FeSi.

• Journal of The Korean Association For Science Education
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• v.27 no.1
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• pp.59-69
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• 2007

The aim of this study was to investigate teachers' perceptions on MBL (microcomputer-based laboratory) experiment training program for teachers, the expecting effects of MBL experiment and application of MBL experiment after conducting MBL experiment training for science classes in schools. This study showed that most of the teachers who participated in the training program thought that the MBL experiment training program was very useful and instructive. Many teachers considered that MBL experiments using a computer could decrease time spent in the experiment by accurate and fast data collection and analysis. They also thought that the reduced time could be used more effectively in the analysis of experimental data and discussion activities leading to correct concept formation as well as in the development of graphical analysis and science process skills. However, they thought that MBL experiments were ineffective in learning how to operate experiment apparatus. This study also revealed that most teachers intended to apply MBL experiments in real classrooms context right after the training course and they pointed out many obstacles in introducing MBL experiments into their classrooms such as a budget to purchase equipment, poor laboratory conditions, and few MBL experiment training opportunities. In order to apply MBL experiment into the real classrooms, further changes were suggested as follows; development of technologies to reduce unit cost of equipment for MBL experiments, production and supply of many kinds of sensors, development of MBL experiment materials, and expansion of the training program for teachers.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.27 no.2
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• pp.114-120
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• 1994

To clarify the effect of storage temperature on the morphological and histological changes of plaice, Paralichthys olivaceus muscle at early stages after killing, the changes in breaking strength of muscle, morphological observation of myofibrils and histological observation of extracellular spaces during storage at $0^{\circ}C\;and\;10^{\circ}C$ were studied. The maximum breaking strength of samples stored at $0^{\circ}C$ was reached within 10hrs and then it dropped significantly (p<0.05) from 10hrs to 25hrs of storage. However, breaking strength was not increased in fresh muscle stored at $10^{\circ}C$ and gradually decreased after 10hrs storage. In myofibrils prepared from dorsal muscle immediately after death, A-band, I-band, H-band and Z-line in sarcomere were clearly distinguishable from each other. Due to muscle contraction, it was not easy to distinguish H-band from I-band observed in sarcomere stored at $0^{\circ}C$ after 10hrs storage. But, in the case of samples stored at $10^{\circ}C$, H-band could be observed dimly until 15hrs of storage. The changes in morphological myofibrils were closely related to increase of breaking strength. No extracellular space was observed among muscle cells immediately after killing. Stored samples at $0^{\circ}C$ showed extracellular spaces after 15hrs storage. On the other hand, samples stored at $10^{\circ}C$ didn't show any extracellular spaces until 15hrs storage and showed extracellular spaces after 24hrs storage. It was thought that the post-mortem tenderization of plaice muscle was closely related to the gradually disintegration of the extracellular matrix structure after killing.

• Journal of the Korea Society of Computer and Information
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• v.29 no.9
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• pp.125-136
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• 2024

This study presents an automated Python algorithm for analyzing rainfall characteristics to establish critical rainfall thresholds as part of a landslide early warning system. Rainfall data were sourced from the Korea Meteorological Administration's Automatic Weather System (AWS) and the Korea Forest Service's Automatic Mountain Observation System (AMOS), while landslide data from 2020 to 2023 were gathered via the Life Safety Map. The algorithm involves three main steps: 1) processing rainfall data to correct inconsistencies and fill data gaps, 2) identifying the nearest observation station to each landslide location, and 3) conducting statistical analysis of rainfall characteristics. The analysis utilized power law and nonlinear regression, yielding an average R² of 0.45 for the relationships between rainfall intensity-duration, effective rainfall-duration, antecedent rainfall-duration, and maximum hourly rainfall-duration. The critical thresholds identified were 0.9-1.4 mm/hr for rainfall intensity, 68.5-132.5 mm for effective rainfall, 81.6-151.1 mm for antecedent rainfall, and 17.5-26.5 mm for maximum hourly rainfall. Validation using AUC-ROC analysis showed a low AUC value of 0.5, highlighting the limitations of using rainfall data alone to predict landslides. Additionally, the algorithm's speed performance evaluation revealed a total processing time of 30 minutes, further emphasizing the limitations of relying solely on rainfall data for disaster prediction. However, to mitigate loss of life and property damage due to disasters, it is crucial to establish criteria using quantitative and easily interpretable methods. Thus, the algorithm developed in this study is expected to contribute to reducing damage by providing a quantitative evaluation of critical rainfall thresholds that trigger landslides.