• Title/Summary/Keyword: Absorptive

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Resilience Assessment for Aquifers close to Groundwater Wells in the Nakdong River Estuary (낙동강 하구 지하수 관정 주변 대수층의 리질리언스 평가)

  • Soonyoung Yu;Ho-Rim Kim;Eun-Kyeong Choi;Sung-Wook Kim;Dong-Woo Ryu;Yongcheol Kim
    • Journal of Soil and Groundwater Environment
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    • v.28 no.3
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    • pp.12-28
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    • 2023
  • Each national groundwater monitoring well showed distinct change patterns in groundwater levels and electrical conductivity (EC) in the Nakdong River Estuary, implying different external forces (EFs) on each well. According to the annual average data in 1997-2020, seawater was invaded into Well C. The desalination rate of -1,062 µS/cm/year represents the adaptive capacity of the well to seawater intrusion. The water levels and EC in Well E responded to precipitation, indicating the low absorptive capacity to climate changes. Meanwhile, Well B showed constant increases in water levels, suggesting that problems by rising groundwater should be considered in the study area where confined aquifers are overlaid by clay aquitards. The other wells showed consistent water levels and EC, indicating resilience to EFs. Here, resilience is the capacity of a well to resist changes by EFs, including the absorptive and adaptive capacity. The resilience of Wells E and F to climate changes was quantitatively compared using a resilience cost (RC). The RC showed Well F was more resilient than Well E, and the bedrock aquifer was more resilient than the alluvium aquifer, supporting the usefulness of RC. The resilience assessment against EFs (e.g., changes in land use and climate) helps sustainable groundwater management.

The Knowledge Transfer Network and Performance of Chinese Subsidiary in Korean MNCs : Focusing on Roles of Absorptive Capacity and Entry Mode (한국 다국적기업의 중국 자회사의 지식이전, 네트워크와 경영성과에 관한 연구 - 흡수능력과 진입방식의 역할을 중심으로 -)

  • Yoon, Ki-Chang
    • Korea Trade Review
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    • v.41 no.5
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    • pp.325-351
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    • 2016
  • This study empirically investigated the relationship among knowledge transfer, network(firm network and government network) and performance Korean MNCs' subsidiaries in terms of absorptive capacity and entry mode roles in China. For this, absorptive capacity was established as an independent variable, mediating variable, and moderating variable. And the entry mode was divided into single investment and joint venture and set to the moderating variable. Data for the analysis of actual proof was randomly selected from the companies which was established more than 3 years before KOTRA 'The overseas expansion Korean company directory (2014)'. Questionnaires to 138 Chinese subsidiaries of Korean MNCs were collected by FAX and E-mail. AMOS was utilized and collected data investigated the role of the absorption capacity and entry mode as the covariance structure analysis. The empirical analysis showed that absorption capacity has a direct influence on management performance as an independent variable with the network (firm network and government network). It only has a partial mediating role between enterprise networks and management performance, and no meaningful result was gained as its moderationg role bewteen the exogenous variable and management performance. And in terms of Korean companies' moderating role in entering China, they have a moderating role between government network, absorption capacity and management performance, but did not show a statistically significant result between knowledge transfer, enterprise network and management performance. Absorption capacity, as the variable affecting overseas subsidiary's management performance, should not be considered a mediating or moderating variable, but an independent variable. Since the joint venture is showing higher performance than single investment when going into the Chinese market, implication is provided for options in overseas expansion. But this research has the limitation in generalization because it is aiming at the subsidiaries of the Korean company investing in China. Therefore, it is more desirable in the future to conduct a study of the subsidiary of the Korean company entering several countries. It also has limitations in generalization, because the research was conducted using a limited number of variables, despite there are various factors affecting the management performance of Chinese subsidiaries.

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Developmental surface ultrastructure of Macroorchis spinulosus in albino rats

  • Hong, Sung-Jong;Woo, Ho-Chun;Kwon, Oh-Sil
    • Parasites, Hosts and Diseases
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    • v.42 no.4
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    • pp.151-157
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    • 2004
  • Developmental surface ultrastructure of Macroorchis spinulosus was studied by scanning electron microscopy. One-day-old juvenile fluke was leaf-shaped and bent ventrally. Body surface was covered densely with peg-like spines and with cobblestone-like cytoplasmic processes. Ciliated sensory papillae were concentrated around oral sucker. Several unciliated sensory papillae occurred equidistantly on oral sucker and acetabulum. The ciliated papillae appeared in two longitudinal lines symmetric bilaterally on dorsal surface. On adult flukes, tegumantal spines became wider in middle of the body surface. The cytoplasmic processes differentiated into more fine velvety form. It is likely that the differentiated fine cytoplasmic processes are an increased absorptive surface to adult M. spinulosus. It is suggested that single pointed tegumental spines on anterior half of the body may be supportive for this fluke to migration.

A Novel Imaging System for Removal of Underwater Distortion using Code V

  • Maik, Vivek;Daniel, Stella;Chrispin Jiji, A.
    • IEIE Transactions on Smart Processing and Computing
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    • v.6 no.3
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    • pp.141-150
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    • 2017
  • Images obtained from underwater are usually degraded due to the environmental conditions. Some of the typical degradation factors include turbidity and color degradation. These degradations can be attributed to the absorptive and scattering properties of underwater degradation in terms of optical parameters, such as modulation transfer function (MTF), optical transfer function (OTF),point spread function (PSF), and color constancy. In this paper, we use the CODE V optical simulation software to mimic underwater conditions and model the imaging platform, thereby studying various parameters, such as PSF and MTF, and we use the PSF to remove the underwater turbidity. Experimental results show increased performance with the algorithm, compared to other existing methods.

A Study on the Surfaces Modification of Tool Steel by YAG LASER (YAG LASER에 의한공구강의 표면개질에 관한 연구)

  • 강형식
    • Journal of the Korean Society of Manufacturing Technology Engineers
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    • v.9 no.2
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    • pp.66-71
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    • 2000
  • Laser induced surface hardening of Tool steel(STC5) can be achieved either with or without surface melting. In trans-formation hardening as the surface is heated to a temperature below its melting point and is rapidly cooled solidified microstructures are usually much finer and stronger than those of the base matals. For this reason surface modification of tool steel by YAG laser irradiation has been studied as a function of processing parameters such as power density pulse width defocusing distance and molten depth. The high energy density changes and refines the microstructure of the near surface layer. In the case of beam passes martensite formed in the melt zone exhibited very high vickers hardness values. Molten depth and width depend on defocusing distance and energy of black color painting is more absorptive than other color painting.

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Leverage Strategy to National R&D Investment in Korea: A System Dynamics Approach (국가 연구개발 투자시스템의 레버리지 전략: 시스템 다이내믹스 접근)

  • Park, Hun-Joon;Oh, Se-Hong;Kim, Sang-Jun
    • Korean System Dynamics Review
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    • v.5 no.2
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    • pp.33-66
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    • 2004
  • This study is an exploratory investigation on how national R&D investments decisions are made in Korea. For developing system dynamic model, we are interested in locating three structural dilemma, occurring with the Korean NIS. In so doing, we intend to devise the ways of ameliorating problems within the NIS investment decision-making process by providing policy implications. We identify delays and side effects during transition periods between different stages of technology innovation by perceiving the switching pattern dynamically, in which form of technologies shifts from one to another stage like paradigm shift, when the R&D investment reaches a certain stock. It is also suggested that the development of strategies is necessary in order to enhance efficiency of technological development process.

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A Study on the Performance Improvement of Medium Speed Diesel Engine Exhaust Silencer in the Low-frequency Range Using Array Resonators (공명기 배열을 이용한 중속 디젤엔진 배기 소음기의 저주파수 대역 성능 개선 연구)

  • Kim, Young-Hyun;Joo, Won-Ho;Bae, Jong-Gug
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • v.19 no.7
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    • pp.693-698
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    • 2009
  • Various acoustic tests were carried out to investigate the acoustic performance of diesel engine exhaust silencers. In order to consider flow effects, the test facility was set up composed of fan, duct and silencer. Using the test facility, insertion loss tests were carried out to improve the acoustic performance in the low-frequency ranges. Through a series of tests, it was found out that the array resonators having multi-perforated holes inside the exhaust silencer, might be very effective in the low frequency range. Consequently, the hybrid-type silencer which is the combination of reflective silencer with array resonators and conventional absorptive silencer, was proposed and its high performance in the low-frequency range was also verified.

A Study on the Improvement of Acoustic Performance of Diesel Engine Exhaust Silencer in the Low-Frequency Range using Array Resonators (공명기 배열을 이용한 디젤엔진 소음기의 저주파수 대역 성능 개선 연구)

  • Lee, Tae-Kyung;Kim, Young-Hyun;Joo, Won-Ho;Bae, Jong-Gug
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2007.05a
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    • pp.30-35
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    • 2007
  • Various acoustic tests were carried out to investigate the acoustic performance of diesel engine exhaust silencers. In order to consider flow effects, test equipment composed of fan, duct and silencer was set up. Using the test equipment, insertion loss tests were carried out to improve the performance in the low-frequency ranges. Through a series of tests, the fact that array resonators may be effective in the low-frequency noise has been verified. Consequently, the hybrid-type silencer which is the combination of reflective silencer with array resonators and conventional absorptive silencer were proposed and its high acoustic performance in the low-frequency range has also been verified.

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Researches on Diagnostic Indices of Skin Diseases Based on Concepts of Interstices (주리개념(腠理槪念)에 근거한 피부과 질병의 진단지표 기초연구)

  • Chi, Gyoo Yong
    • Journal of Physiology & Pathology in Korean Medicine
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    • v.27 no.2
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    • pp.167-172
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    • 2013
  • In order to establish the diagnostic indices of skin diseases, some physiological and pathological concepts of interstices(腠理) were researched based on , and western dermatology with etymological analysis. As physiological indices for diagnosis of skin diseases, measurement of epidermis and dermis using ultrasonogram in the zhongwan and dachui's location. And for grading looseness and fineness of interstices with 3 unsound groups, measuring numbers and sizes of sweat pores in each point's 1 cm diameter circular area using comparative method and palpation assessment. Another index is superficial temperature. As pathological indices for diagnosis, validating volumes of dead skin cells and grading degrees of atrophy and degeneration of skin lesion. And as supplementary measures, absorptive degrees of cosmetics on face should be recorded according to 3 grades. These diagnostic indices can contribute to establishment of standard pattern identification and prescription of skin diseases through converting anatomical cognizance into classical concepts of interstices objectively.

Application of Wavenumber-TD approach for time harmonic analysis of concrete arch dam-reservoir systems

  • Lotfi, Vahid;Zenz, Gerald
    • Coupled systems mechanics
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    • v.7 no.3
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    • pp.353-371
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    • 2018
  • The Wavenumber or more accurately Wavenumber-FD approach was initially introduced for two-dimensional dynamic analysis of concrete gravity dam-reservoir systems. The technique was formulated in the context of pure finite element programming in frequency domain. Later on, a variation of the method was proposed which was referred to as Wavenumber-TD approach suitable for time domain type of analysis. Recently, it is also shown that Wavenumber-FD approach may be applied for three-dimensional dynamic analysis of concrete arch dam-reservoir systems. In the present study, application of its variation (i.e., Wavenumber-TD approach) is investigated for three-dimensional problems. The method is initially described. Subsequently, the response of idealized Morrow Point arch dam-reservoir system is obtained by this method and its special cases (i.e., two other well-known absorbing conditions) for time harmonic excitation in stream direction. All results for various considered cases are compared against the exact response for models with different values of normalized reservoir length and reservoir base/sidewalls absorptive conditions.