• 한국정밀공학회지
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• 제32권12호
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• pp.1031-1037
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• 2015

Laser assisted machining (LAM) is an effective method with which to effectively process difficult-to-cut materials. Simple machining processes, such as turning and linear tool paths, have been studied by many researchers. But, there are few research efforts on LAM workpieces using threedimensional shapes because of difficulties controlling the laser heat on workpieces with inclined angles or curved surfaces. Two methods for machining three-dimensional workpieces are proposed in this paper. The first is that the heat source shape and laser focal length are maintained using an index table. Second, a rotary type laser module is controlled using an algorithm to move the laser heat source in all directions. This algorithm was developed to control the rotary type laser module and the machine tool simultaneously. These methods are verified by a CATIA simulation.

• 셀메드
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• 제5권4호
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• pp.24.1-24.7
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• 2015

Bahunia racemosa family, Caesalpiniaceae, is one of the precious resources of the earth. It has played a significant role in human civilization since ancient times. It is tall sized tree growing throughout India, Ceylon, China, and Timor. The different part of this plant contains β-sitosterol and β-amyrin, flavonols (kaempferol and quercetin) and two coumarins (scopoletin and scopolin), tannins etc. Various part of this plant has great pharmacological potential with a great utility and usage as folklore medicine as analgesic, antipyretic, anti-inflammatory, antispasmodic and antimicrobial activity. This review mainly focus on the exclusive review work on the traditional, phytochemical and pharmacological activities of this plant.

• 한국자원식물학회지
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• 제33권3호
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• pp.200-219
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• 2020

We performed taxonomic reviews and habitat circumstances survey for 41 un-introduced environmentally harmful plants (as designated by the Ministry of Environment, Korea in 2016). For this purpose, we investigated plant specimens from several herbaria and performed a field survey in the southeastern region of the United States. Base on the result, we presented the most comprehensive results of weed risk evaluation and taxonomic description up to now as well as classification keys for 11 species to apply the regulation management of putative invasive alien species - Centaurea maculosa Lam., Centaurea diffusa Lam., Mikania micrantha Kunth. (Asteraceae), Cenchrus echinatus L., Neyraudia reynaudiana (Kunth) Keng ex Hitchcock, Brachiaria mutica (Forsskål) Stapf, Vulpia bromoides (L.) Gray, Lolium persicum Boissier & Hohennacker, Setaria palmifolia (J. Konig) Stapf (Poaceae), Prosopis glandulosa Torr. (Fabaceae), Fallopia baldschuanica (Regel) Hobub. (Polygonaceae).

• 대한기계학회논문집
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• 제19권3호
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• pp.741-750
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• 1995

The turbulent buoyancy-driven flow in 2-dimensional enclosed cavities heated from the vertical side is numerically calculated for both cases of a Rayleigh number of 5*10$^{10}$ for air and 2.5*10$^{10}$ for water. Three different turbulence models are considered : standard k-.epsilon. model of Ozoe and low-Reynolds-number model of Lam and Bremhorst, and another low-Reynolds-number model of Davidson. The results indicate that the use of low-Reynolds number models is recommended for the indoor airflow computation, and the results from Davidson model are reasonably close to the reported experimental data. A sensitivity study shows that the amounts of wall-heat transfer and the velocity profiles with the Lam and Bremhorst model largely depend on the choice of the wall function for .epsilon..

• 한국정보통신학회논문지
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• 제9권5호
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• pp.965-972
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• 2005

본 논문에서는 멀티미디어 Ad Hoc 무선 LAM(AWLAN)을 위한 새로운 자원 관리 방안으로 분산채널 할당 프로토롤(Distributed Channel Allocation Protocol, DCAP)을 제안한다 이 방안은 QoS (Quality-of-Service)를 보장하는 분산적 자원 관리를 OFDM-CDMA(Orthogonal Frequency Division Multiplexing-Code Division Multiple Access) 채널 구조 위에 구현한 것이다. MPEG 트래픽에 대한 성능평가 결과 DCAP는 광대역 무선 접근(Broadband Wireless Access, BWA) 형 물리구조 기반에서의 멀티미디어 서비스를 지원하는 AWLAN을 위한 좋은 자원 관리 방안임이 판명되었다.

• 한국초지조사료학회지
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• 제7권3호
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• pp.135-139
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• 1987

The influence of ploidy level on agronomic characteristics in italian ryegrass, Lolium multiflorum Lam, italicum, was studied using diploids (2x) and tetraploids (4x) on the upland of Livestock Experiment Station, Suweon. The results are summarized as follow: 1. Tetraploid cultivars are in general dark green in leaf color and strong glittered. 2. Diploid cultivars are more resistant to cold than tetraploids but degree of resistance to cold depends on cultivars. The di-and tetraploids did not differ in summer survival and coldand heat resistance of di-Itetraploid cultivars were not related. 3. Tetraploid cultivars have larger leaf-blades, more rapid growth and higher leaf ratio to stem by heading than diploids. 4. Tetraploids possess significantly lower dry matter content than diploids. 5 . Fresh- and dry weight of tetraploids are similar with that of diploids but tetraploids are more leafy than diploids. 6. Seasonal yield depends more on the type of the cultivar than on its tetraploid nature.

• Steel and Composite Structures
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• 제25권2호
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• pp.177-186
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• 2017

In this work, the model of magneto-thermoelasticity based on memory-dependent derivative (MDD) is applied to a one-dimensional thermal shock problem for a functionally graded half-space whose surface is assumed to be traction free and subjected to an arbitrary thermal loading. The $Lam{\acute{e}}^{\prime}s$ modulii are taken as functions of the vertical distance from the surface of thermoelastic perfect conducting medium in the presence of a uniform magnetic field. Laplace transform and the perturbation techniques are used to derive the solution in the Laplace transform domain. A numerical method is employed for the inversion of the Laplace transforms. The effects of the time-delay on the temperature, stress and displacement distribution for different linear forms of Kernel functions are discussed. Numerical results are represented graphically and discussed.

• Geomechanics and Engineering
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• 제24권4호
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• pp.399-406
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• 2021

It is a key issue in the tunnel design to evaluate the stability of the excavation face. Two efficient analytical models in the context of the limit equilibrium method (LEM) and the limit analysis method (LAM) are used to carry out the deterministic calculations of the safety factor. The safety factor obtained by these two models agrees well with that provided by the numerical modelling by FLAC 3D, but consuming less time. A simple probabilistic approach based on the Mote-Carlo Simulation technique which can quickly calculate the probability distribution of the safety factor was used to perform the probabilistic analysis on the tunnel face stability. Both the cumulative probabilistic distribution and the probability density function in terms of the safety factor were obtained. The obtained results show the effectiveness of this probabilistic approach in the tunnel design.

• 한국진공학회지
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• 제4권S1호
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• pp.130-137
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• 1995

Deopsition of thermal quality SiO2 using a high density plasma ECR CVD process has been demonstrated to give void and seam free gap fill of high aspect ratio metallization structures with a simple oxygen-silane chemistry. This is achieved by continuous sputter etching of the film during the deposition process. A two-step process is utilized to deposit a composite layer for higher manufacturing efficiency. The first step, which has a deposition rate of approximately 0.5 $\mu$m/min., is used to provide complete gap fill between the metal lines. The second step, which has a deposition rate of up to 1.5 $\mu$m/min., is used to deposit a total thickness of 2.0$\mu$m for the intermetal dielectric film. The topography of this composite film is very compatible with subsequent chemicl mechanical polishing(CMP) planarization processing.

• 한국자기학회:학술대회 개요집
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• 한국자기학회 2007년도 The 1st International Symposium on Advanced Magnetic Materials
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• pp.17.2-17.2
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• 2007