• Korean Journal of Plant Resources
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• v.32 no.4
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• pp.379-406
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• 2019

A floristic study on the vascular plants from Juwangsan National Park was conducted 13 times in total, from March to October 2017. Based on the voucher specimens and pictures, it was revealed that the vascular plants in this region comprised 758 taxa: 112 families, 399 genera, 672 species, 4 subspecies, 72 varieties, and 10 forma. Among these plants, 221 taxa were recorded for the first time from this region. The taxa in category II of endangered plants designated by the Korean Ministry of Environment were two taxa, including Eleutherococcus senticosus (Rupr. & Maxim.) Maxim. and Epilobium hirsutum L. The rare plants numbered 5 taxa designated by National Institute of Biological Resources were also found. 20 taxa of Korean endemic plants including Corydalis alata B.U.Oh & W.R.Lee, Iris odaesanensis Y.N.Lee, and Scrophularia cephalantha Nakai were investigated in this region. 40 taxa of floristic regional indicator plants in the 3rd to the 5th degrees were identified. Naturalized plants of 55 taxa were recorded, and 3 taxa of ecosystem disturbance plants, which were Ambrosia artemisiifolia L., Aster pilosus Willd., and Lactuca scariola L., also found.

• Geomechanics and Engineering
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• v.6 no.5
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• pp.437-453
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• 2014

This paper studies the swelling and strength characteristics of unimproved and improved expansive soils in terms of the swell potential, swelling pressure, rate of secondary swelling, unconfined compressive strength and California bearing ratio (CBR). The admixtures used in this study are locally available cement and fly ash. The soils used in this study were taken from the Mae Moh power plant, Lampang Province, in northern Thailand. A conventional consolidation test apparatus was used to determine the swelling of the soil specimen. The optimum admixture contents are determined to efficiently reduce the swelling of unimproved soil. The rate of secondary swelling for unimproved soil is within the range of highly plastic montmorillonite clay, whereas the specimens improved with optimum admixture contents can be classified as non-swelling kaolinite. A soil type affects the swelling pressure. Expansive soil improvement with fly ash alone can reduce swelling percentage but cannot enhance the unconfined compressive strength and CBR. The strength and swelling characteristics can be predicted well by the swelling percentage in this study.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.21 no.1
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• pp.173-179
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• 1997

The high temperature fatigue tests were performed using the specimens taken from Cr-Mo-V steel, widely used as thermal power plant turbine materials for examination fatigue behavior of materials in power plants which have been operated for long periods. The fatigue tests at high temperature were performed at the various temperature and applied stress. The results obtained are summarized as follows : The fatigue crack length increases and the fatigue life decreases with temperature and applied stress according to the same number of stress cycle. The fatigue crack propagation and the fatigue life were much influenced by temperature and applied stress.

• Korean journal of applied entomology
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• v.43 no.2
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• pp.91-101
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• 2004

Thirty-six species of the tribe Tortricini (Tortricidae) in Northeast China are listed with available information. Among them, two species, Acleris hastina (Linnaeus) and A. laiordairana (Duponchel), are reported for the first time from China. Croesia crataegi (Kuznetsov) is newly recorded from Northeast China. Available information, including host plant, distributional range, and biological record, are enumerated.

• Transactions of the Korean Society of Pressure Vessels and Piping
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• v.7 no.2
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• pp.21-25
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• 2011

Although many defects in PZR heater sleeve have been reported continually from operating experiences in oversea nuclear power plant, utilities get into difficulties in finding appropriate methods for diagnostics of the components due to the limited access or high radiation problems. Recently, as an alternative, diagnostics using Guided Wave Testing(GWT) are proposed and the attention of the methods has been growing gradually because of their long range inspection capability. This study is to investigate the effectiveness of GWT to detect PWSCC in welding points of PZR heater sleeve. Moreover, mode sensitivity analysis of GWT and optimal frequency for the diagnostics of PWSCC are presented by testing the mock-ups specimens that contain artificial flaws.

• The KSFM Journal of Fluid Machinery
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• v.1 no.1 s.1
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• pp.17-23
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• 1998

The blade failures are identified as the leading cause of unplanned outages for steam turbine. Most investigations of the failures are limited to material tests, chemical analysis of deposits, and possibly examination of material specimens. But to correct a blading problem requires more than positive identification of the mechanisms involved. An analytic procedure capable of predicting stress and dynamic characteristics of turbine blades is presented to increase steam turbine availability by decreasing blade failures. Finite element method is used to model and predict natural frequencies, steady and dynamic stresses of turbine blades. The procedure is illustrated by the case study. This procedure is used to guide, and support the plant manager's decision to avoid a costly, unplanned outage

• Journal of the Korean Society for Precision Engineering
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• v.17 no.4
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• pp.85-96
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• 2000

An Eggcrate assembly is an important part to hold and support 16,000 tubes containing hot and contaminated water in the steam generator of nuclear power plant. As a great number of tubes should be inserted into the eggcrate assembly, the dimensions of each eggcrate grid are one of the critical factors to determine the availability of tube insertion. in this paper. we propose a machine vision algorithm for measuring the inner-circle diameter of each eggcrate grid whose shape is not exact quadrangular. The overall procedure of the algorithm is composed of camera calibration, eggcrate image preprocessing, grid height adjustment, and inner-circle diameter estimation. The algorithm is tested on real specimens and the results show that the algorithm works fairly well.

• Korean journal of applied entomology
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• v.50 no.1
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• pp.75-77
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• 2011

Two species of the genus Andaspis, Andaspis crawii (Cockerell) and Andaspis kashicola (Takahashi) are newly recorded in the Korean fauna of armored scales (Diaspididae). A key to species of Andaspis, illustrative photographs and information on the distribution and hosts of each species, are also provided to identify the specimens of Andaspis collected in Korea.

• Proceedings of the KSME Conference
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• 2007.05a
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• pp.1702-1707
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• 2007

The reduction of pipe-thickness induced by flow accelerated corrosion (FAC) is one of the most serious problems on the maintenance of piping system in nuclear power plants (NNP). If the thickness of a pipe component is reduced below the critical level, it cannot sustain pressure and consequently results in leakage or rupture. For this reason, wall thinning by FAC has been inspected in secondary side piping systems in NPPs. In this research Round Robin Test (RRT) was conducted to verify confidence of wall thinning measurement system in NPP. 12 inspectors from 3 companies participated and 23 specimens were used according to standard practice in RRT. The gage R&R analysis was introduced in regard to repeatability and reproducibility that are affected to measurement system errors. Confidence intervals of thickness measurement system were obtained.

• Journal of Fashion Business
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• v.11 no.1
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• pp.125-135
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• 2007

Each cotton fiber is a unicellular hair collected from the seed of cotton plant. The fiber contains many convolutions along its length. Mercer was the first to suggest caustic soda treatment of cotton in commercial application. Mercerization has been commercially used since Lowe's suggestion to endow cotton with increased strength and affinity for dyes with additional properties such as fabric touch or luster. In this study, cotton fabric specimens were mercerized to investigate the changes in physical and mechanical properties pertaining to the hand or touch of fabrics. Physical properties were measured using the KES(Kawabata Evaluation System).