• International Journal of Fluid Machinery and Systems
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• v.7 no.4
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• pp.160-173
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• 2014

Surge phenomena in multi-stage axial flow compressors were studied with attention to the frequency behaviors. A new parameter "volume-modified reduced surge frequency" was introduced, which took into consideration the essential surge process, i.e., emptying and filling of the working gas in the delivery plenum. The behaviors of the relative surge frequencies at the stall stagnation boundaries, compared with the corresponding duct resonance frequencies, have demonstrated the existence of two types of surges; i.e., a near-resonant surge and a subharmonic surge. The former, which has fundamentally a near-resonance frequency, occurs predominantly at the stall stagnation boundary for the short -and-fat plenum delivery flow-path and the long-and-narrow delivery duct flow-path, and possibly in the intermediate conditions. The latter, which has a subharmonic frequency of the fundamental near-resonant one and occurs mainly in the intermediate zone, is considered to be caused by the reduced frequency restricted to a limited range. In relation with those dimensionless frequencies at the stall stagnation boundary, the surge frequency behaviors in more general situations away from the boundaries could be estimated, though very roughly.

• East Asian Economic Review
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• v.19 no.1
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• pp.71-97
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• 2015

This study examines the effects of several factors indicating economic openness-imported intermediate goods, total imports, IFDI (inward foreign direct investment), and foreign ownership-on regular, irregular jobs and the ratio of irregular employment to regular employment. Findings revealed that imported intermediate inputs and IFDI affected neither regular nor irregular job figures. However, an increase in total imports led to a decrease in the number of irregular jobs without affecting regular full time jobs, leading to a decrease in the ratio of irregular jobs to regular jobs. On the other hand, changes in foreign ownership structure had a contrary effect, that is, a decrease in the number of regular jobs and an increase in irregular ones, and, thus, an increase in the ratio of irregular jobs to regular jobs. Overall results showed that a rise in imports results in depressed overall employment, irregular employment in particular, while more IFDI results in more irregular jobs replacing regular ones, effectively exacerbating job insecurity. The implication of this analysis is that greater economic openness may have a negative impact on the South Korean labor market overall.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.10 no.5
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• pp.832-842
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• 2006

Wireless Personal Area Networks(WAPANs) are designed for short-range ad hoc connectivity among portable devices. They have gained much attention in the industry recently. One of them, High-rate WPAN, is designed to support multimedia traffic that requires high data rates. But, High-rate WPAN standards don't specify the time slot assignment scheduling method of CAT(Channel Time Allocation). So, there has been many studies regarding time slot assignment scheduling of CAT. However, present studies involve demerits about not applying various types of errors in air interlace or having a starvation of a specific DEV(data device). In this paper, we propose algorithms about supplying the intermediate channel assignment in order to avoid these demerits. This method will help other methods that use time slot assignment scheduling of CTA.

• Journal of the Institute of Convergence Signal Processing
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• v.7 no.1
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• pp.1-10
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• 2006

To reduce the complexity of video transcoder, transcoding techniques generally use intermediate data such as macroblock types, motion vectors, DCT coefficients, which are extracted from incoming video bitstream. In this Paper, we Propose a new adaptive INTRA update scheme utilizing the importance of each macroblock in a given frame. The importance measure is calculated from the motion vectors which are extracted from the decoding procedure of a incomming video data.'rho ratio of the macroblock to be referred by the next frame is calculated by the motion vectors of the next frame and the macroblocks to be refered higher ratio has more effect on the next frame and the followed frames. The proposed scheme can obtain transcoded bitstreams which has better image quality and more improved resilience against transmission errors.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.18 no.1
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• pp.125-134
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• 1996

Mucoepidermoid carcinomas, first reported by Volkman(1895), form 6% to 9% of all salivary tumors. Two thirds affecting the parotid gland and the remaining third, the minor glands. As we could know from its name, mucoepidermoid carcinomas originate from ductal epithelium including squamous, mucous-secreting, and undifferentiated intermediate cells. Histologically, it is classified as well-differentiated (low grade), moderately-differentiated(intermediate grade), and poorly-differentiated (high grade) types and the treatment method and prognosis are influenced from its histological grade. We have experienced two cases of mucoepidermoid carcinoma treated surgically with good results and now would like to report these with review of literatures.

• Journal of Korean Society of Rural Planning
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• v.9 no.3 s.20
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• pp.25-34
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• 2003

This study was carried out to propose some useful advices for the improvement policy of the minor rural roads. For the detailed case studies on structural improvement level of the minor rural roads, 5 county areas in Chonnam Province were selected ; Damyang (peri-urban), Gurye(remoter mountainous), Jindo(remotest island), Yuongam(intermediate flat) and Bosung (intermediate semi-mountainous). In each county, the official survey data on pavement types, widths and ratios of district(Myun in Korean) and parish(Ri in Korean) roads were collected. There were no apparent differences between district and parish roads in terms of structural improvement level, while the former was ranked higher than the latter in the minor rural road improvement law, so, the present hierarchial classification system of rural roads should be readjusted. And above a third of minor rural roads in the case study areas did not meet the statutory minimum level of road width, which means the necessity of substantial upgrade of road improvement works in rural areas.

• Cross-Cultural Studies
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• v.22
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• pp.303-327
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• 2011

This study aims to uncover the learner's language proficiency shown in the writing data of Chinese elementary/intermediate level learners. Language proficiency of the learners acquired by error analysis provides only partial information, and thus this study analyses the interlanguage of Korean learners in terms of 'Mean Length of Utterance, MLU' to discover the overall aspect of learner's language proficiency more symmetrically. The analysis of vocabulary area is to be enforced after generally studying the learner's language development aspect in accordance with MLU-m(orpheme) and MLU-(w)ord found in compositions by Chinese speaking Korean language learners. In terms of MLU, it has been slightly increased as the level of proficiency between elementary level and intermediate level learners; however, the morpheme seemed to be difficult to use, since the difference between Chinese learners and Korean university students has been notably shown. Vocabulary diversity, using aspect for each word class, and using aspect of the predicate are studied for vocabulary area; more various and numerous vocabulary tend to be used as the level of proficiency increases. In terms of predicate use, Chinese learners use less numerous vocabulary types.

• Design & Manufacturing
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• v.15 no.3
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• pp.39-44
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• 2021

In molding of continuous fiber-reinforced thermoplastic composites, it is very difficult to impregnate between the reinforcements and the matrix since the matrix has a high melting temperature and high viscosity. Therefore, most of composite molding processes are divided in the manufacturing processes of intermediate materials called prepreg and the forming of products from intermediate materials. The divided process requires additional facilities and thermoforming, and they increase the cycle time and cost of composite products. These problems can be resolved by combining the continuous fiber-reinforced composite molding process with injection molding. However, when a composite material is manufactured by inserting woven fabric into the injection mold, poor impregnation occurs on the surface of the molded product. It affects the properties of the composites. In this paper, through an impregnation experiment using cores with different heat transfer rates and pore densities, the reason for the poor impregnation was confirmed, and molding experiments were conducted to produce composite with improved surface impregnation by inserting the mesh. And also, the surface impregnation and deformation of composites molded using different types of mesh were compared with each other.

• Journal of Forest and Environmental Science
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• v.38 no.4
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• pp.284-289
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• 2022

This study was conducted to determine the seed dormancy types of Sambucus racemosa subsp. pendula Nakai and S. williamsii Hance. Low temperature stratification (1, 2, 3, 4 months) and GA3 treatment (1,000 mg/L) were performed on seeds to determine the type of seed dormancy. After the treatment, seeds were placed on a petri dish at 25℃ under light conditions. The germination rate and mean germination time were investigated. Results showed that cold stratification was effective in breaking the dormant state of the seed in both species. In the low temperature stratification treatment, the seed germination performance was improved as the treatment period was prolonged. Gibberellin treatment was effective in breaking the dormant state of S. racemosa subsp. pendula without low temperature stratification. However, S. williamsii did not break the dormant state of the seed by gibberellin treatment without low temperature stratification treatment. In the gibberellin treatment, germination performance was improved according to the low temperature stratification treatment period. As a result of this study, the seeds of S. williamsii have both an intermediate complex and a deep complex morphophysiological dormancy (MPD). In comparison, it was found that the S. racemosa subsp. pendula had intermediate composite MPD.

• Nuclear Engineering and Technology
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• v.25 no.3
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• pp.447-456
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• 1993

A simplified model to assess the performance of engineered barrier for the retardation of radionuclide release in a low- and intermediate-level radioactive waste repository was developed. The model is based on the repository design concept being suggested in Korea, and considers two types of release scenario ; a design-bas release for the design of engineered barrier and a realistic release for the performance assessment. For the numerical illustration, the sample calculations were performed for five radionuclides with different chemical characteristics, and the results were analyzed.