• The Journal of the Acoustical Society of Korea
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• v.13 no.5
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• pp.5-14
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• 1994

In this study, the ground impedance is measured using the standing wave method in a free field on the grass, the soil, and the ground covered with asphalt and cement. And the excess attenuation of sound is investigated. Results are obtained in the frequency range between 300Hz and 1000Hz. There are very good agreements between the results of the measured ground impedance and the prediction of Delanyand Bazley. The ground impedance is increased in order the grass, the soil, the asphalt and the cement road, decreased with frequency for each the ground. The excess attenuation of sound is mainly determined by the ground impedance. The experimental results of the excess attenuation over the different types and the microphone heights are compared with the theoretical values.

• Journal of Engineering Education Research
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• v.3 no.2
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• pp.31-37
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• 2000

Recently, internet applications for efficient cyber education have drawn much interests. The world-wide web provides new opportunities for cyber education over the internet. This paper presents a virtual lab system which can be used on the world-wide web. The proposed virtual lab system provides the improved learning methods which can enhance the educational efficiency in engineering experiments. If the students enter the virtual lab system on the web, they can make an experiment on basic electrical and electronic principles through simple mouse manipulation. Since proposed virtual lab system is implemented to describe the actual lab system, the students can obtain similar experimental data through it. Several sample Java applets are illustrated as examples.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2011.04a
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• pp.328-331
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• 2011

준정적 횡하중을 재하 받는 철근콘크리트 보-기둥 접합부의 전단강도에 대한 주요 영향요인을 Bayesian parameter estimation의 신뢰성 이론 접목을 통해 검토하였다. 이와 같은 연구 scope의 수행을 위해 철근콘크리트 보-기둥의 실험 database가 구축되었다. 실험 database는 일정한 criteria을 적용하여 구축되었으며, 포함된 시편들은 최종적으로 접합부 내의 전단파괴가 지배하는 경우들이다. 포함된 시편들의 상세는 ACI (American Concrete Institute) 352R-02를 기준으로 평가되어졌다. 보-기둥 접합부의 전단강도에 영향 요인을 편중되지 않게 평가하고자, Bayesian parameter estimation의 신뢰성 이론을 적용하였다. Bayesian parameter estimation의 적용을 통해 전단강도에 영향이 적은 변수 (not informative parameter)를 순차적으로 제거 (stepwise removal process)함으로 주요 영향요인의 우선 순위를 확인할 수 있었다. 검토된 8개의 변수들 중에서, 횡하중을 재하 받는 철근콘크리트 보-기둥의 전단강도는 주로 콘크리트 압축강도, in-plane geometry, 종방향 보의 주철근 그리고 접합부 내의 구속철근 순으로 영향을 줌을 알 수 있었다.

• Journal of muscle and joint health
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• v.28 no.2
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• pp.161-173
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• 2021

Purpose: This study examined: 1) what it meant for patients to have multimorbidity 2) how they manage their illness using health care facilities, and 3) what contextual backgrounds exist regarding the health care system. Methods: This qualitative research obtained individual in-depth interviews from 22 patients. Participants were selected by purposive sampling among those who saw physicians more often than the national average from the 2013 medical-claim data. The transcribed data were analyzed using Ground theory. Results: Multimorbidity patients suffered from "chain-like serial symptoms" and "pain without a breakthrough". They expressed themselves as "indeed patients among patients", "my body is a general hospital", and "an incompletely normal person". There was a demand to resolve the anxiety arising from the situation in which the body keeps getting sicker without showing any signs of recovery. In a state of reduced social support and a lack of trust in the doctor, their desire to be healed led them to receive a temporary relief through dependence on medical institutions. Conclusion: This research recognized the desire of multimorbidity patients to seek temporary relief through dependence on medical institutions. A more patient-centered directed care plan, specific to the needs of the patients with multimorbidity is required.

• Korean Journal of Occupational Health Nursing
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• v.31 no.2
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• pp.66-76
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• 2022

Purpose: This study aimed to explore the constructs and context of hospital nurses' organizational silence. Methods: In-depth interviews were conducted with 17 nurses in small-middle general hospitals as well as big university hospitals. We then derived the key themes using grounded theory method. Results: Nine themes and 30 sub-themes were derived: "Willing to be recognized for performance rather than saying", "Getting used to the hard-to-speak climate", "Face the reality that does not change when said", "Complicated situation that prevents self-regulating decision-making", "Conflicts that are difficult to confront", "Unfair responsibilities that I want to evade", "Leaders who don't support me", and "Being blocked in communication". Consequently, the nurses learned to adopt a climate of silence and "learned organizational silence" behavior. They experienced that prosocial silence was essential for obtaining approval as a member of the group, and defensive silence for protecting themselves in the hierarchical structure and unfair responsibilities. Acquiescent silence originated from a futile relationship with their supervisors, one-way communications, and the unsupportive management system, in which three types of silence appeared sequentially or in combination with each other. Conclusion: Based on these results, nursing managers should identify the context of nurses' organizational silence and should lessen these silence behaviors.

• Journal of the Korean Institute of Landscape Architecture
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• v.42 no.6
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• pp.111-123
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• 2014

The city square is an important public open space for people. Being used for various activities, such as community gatherings, open markets, concerts, political rallies, and other events, many types of city squares are represented in a city. Nevertheless, most city squares are planned uniformly, lacking consideration for visitor behavior and use satisfaction. The study investigated the design factors and subcomponents influencing user satisfaction with different types of city squares. This study focused on the general city square in Seoul, including the grand public place (i.e. Gwanghwamun Square) and the neighborhood park (i.e. Geumbit Square). The data were analyzed using factor analysis, linear regression and fuzzy theory. The results of the study are as follows: first, five design factors of satisfaction with city squares are identified (Amenity, Usability, Spatial components, Culture, and Comfortableness). Second, Amenity, Comfortableness, and spatial components significantly affect user satisfaction with Gwanghwamun in that order. On the other hand, in Geumbit Square, Comfortableness, Amenity, Usability and Spatial components affect user satisfaction in a significant way, in that order. Third, cleanliness, a subcomponent of amenity, was ranked highest using the fuzzy theory function for satisfaction with Gwanghwamun Square. Otherwise, the prevalence of plants was ranked the highest on the Geumbit Square survey. The study compared design factors influencing satisfaction in the public grand place and the neighborhood park. The results have implications for designing and planning city squares to the satisfaction of their visitors.

• Journal of the Korean Society for Railway
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• v.11 no.4
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• pp.424-432
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• 2008

This paper presents theoretical explanations about the spill-over effects of domestic production of light rail transit and empirically investigates its effects on output, value-added and employment in the Korean economy. We distinguish net gains of domestic production from gross effects that bring about whether localized or imported cars are used. The input-output analysis is employed to fully capture the interaction among various industries involved. The empirical results reveal that net gains of domestic production such as import substitution, improvement of trade balances, and increase in output, value-added and employment are enormous. The cost reduction in construction, E&M systems, cars, management, and tariff and transportation is also significant.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.23 no.1
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• pp.49-62
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• 2018

Net community production (NCP), defined as the difference between net primary production and respiration of heterotrophs, has been used as a measure of oceanic biological carbon pump. This paper summarizes the theoretical background and experimental methods for the estimation of NCP based on $O_2/Ar$ measurements ($O_2/Ar-NCP$). The high frequency measurements of $O_2/Ar-NCP$ (<1 min) is a significant enhancement over the conventional measures of biological pump, such as new production and export production. This paper also introduces some of important works as to the comparison between $O_2/Ar-NCP$ and other measures of biological pump, the distributions of $O_2/Ar-NCP$ in the oceans, and the correlation of $O_2/Ar-NCP$ with various oceanic parameters, including community structures.

• Journal of the Korean Chemical Society
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• v.59 no.5
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• pp.387-396
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• 2015

The DFT and ab initio calculations have been performed to elucidate hydrogen interaction of HOOO-(H₂O)_n (n=1~5) clusters. The optimized geometries, harmonic vibrational frequencies, and binding energies are predicted at various levels of theory. The trans conformer of HOOO monomer is predicted to be thermodynamically more stable than cis form at the CCSD(T) level of theory. For HOOO-(H₂O)_n clusters, the geometries are optimized at B3LYP/aug-cc-pVTZ and CAM-B3LYP/aug-cc-pVTZ levels of theory. The binding energy of HOOO-H₂O cluster is predicted to be 6.05 kcal/mol at the MP2//CAM-B3LYP/ aug-cc-pVTZ level of theory after zero-point vibrational energy (ZPVE) and basis set superposition error (BSSE) correction. The average binding energy per H₂O is increased according to adding a H₂O moiety in HOOO-(H₂O)_n clusters up to 7.2 kcal/mol for n=5.

• Journal of the Korean Chemical Society
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• v.59 no.2
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• pp.117-124
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• 2015

The DFT and ab initio calculations have been performed to elucidate hydrogen interaction of hydrogen polyoxide dimers, $H_2O_n-H_2O_m$ (n=1-4, m=1-4). The optimized geometries, harmonic vibrational frequencies, and binding energies are predicted at various levels of theory. The harmonic vibrational frequencies of the molecules considered in this study show all real numbers implying true minima. The higher-order correlation effect were discussed to compare MP2 result with CCSD(T) single point energy. The binding energies were corrected for the zero-point vibrational energy (ZPVE) and basis set superposition errors (BSSE). The largest binding energy predicted at the CCSD(T)/cc-pVTZ level of theory is 8.18 kcal/mol for $H_2O_4-H_2O_3$ and the binding energy of water dimer is predicted to be 3.00 kcal/mol.