• Land and Housing Review
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• v.2 no.4
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• pp.397-406
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• 2011

This research aims to develop various infill-systems for practically applying to long-life housing with 100-year durability and flexibility as a strategy for realizing sustainable residential environment. Especially, the developed infill-systems & technologies were concentrated to the mock-up house applied with the standard model of long-life housing, and their in-situ applicability by a phase, experts' consultation, and questionnaire survey were also evaluated. This research was executed to divide by 3 phases. In the First phase infill-systems for a housing unit of $84m^2$ exclusive use area as well as a support of whole structure and infill-systems including dry wall, and windows were constructed, and their in-situ applicability were evaluated. In the Second phase vertical integration of upper and lower housing units of $50m^2$ and $40m^2$ exclusive use area was investigated the first in domestic for 3 housing units of $50m^2$ exclusive use area. In addition, various infill-systems including the horizontal expansion of $50m^2$ and $10m^2$ exclusive use areas were also constructed and evaluated on their in-situ applicability. In the third phase diverse performance tests and field investigation for in-situ verifying of dry Ondol, developed this research, were executed to improve their practicability. Inner dry walls were taken apart, moved and re-constructed for verifying their practicability to investigate 3R-Reduce, Reuse and Recycle-realization too.

• Journal of Korea Water Resources Association
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• v.38 no.8 s.157
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• pp.631-643
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• 2005

The objective of this study is to perform hydraulic and numerical model experiments of the flows in circulation-water-pump(CWP) chambers of combined cycle power plants (CCPP) to be built and to suggest improvement plans if the flows might cause a serious problem on the operation of CWPs. Hydraulic model was constructed in a scale of 1 to 20 using acrylic sheets and a two dimensional numerical model used was RMA2. To evaluate results of Hydraulic and numerical model experiments, evaluation criteria of flow conditions in the intake canal and CWP chambers were determined. Vertical vorticities obtained from numerical simulations for the initial plan of CCPPs were qualitatively compared with results of hydraulic model experiments and the formation possibility of a large scale vortex, one of the flow evaluation criteria, was evaluated. The initial plan was found not to satisfy the flow evaluation. Nine improvement plans were devised and numerically simulated. Four alternative plans among nine improvement plans were selected and hydraulically experimented. On the ground of the results of hydraulic model experiments, a final improvement plan, one of four improvement plants, was suggested. When CWP chambers and intake canals were designed with spatial constraints, flow separating wall and guide walls were found to improve flow conditions in CWP chambers.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.47 no.3
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• pp.227-235
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• 2021

In this study, we have prepared pure planar-type ZnO and calamine powder containing both ZnO and Fe₂O₃ components as a raw material for cosmetics with UV and blue band blocking functions. The planar-type ZnO ceramic powder having a high aspect ratio in the range of 20:1 to 50:1 was synthesized by precipitation method in a zinc acetate and sodium citrate mixed solution with the electrolyte obtained by power generation with a zinc-air battery. The content of Fe₂O₃ in the artificial calamine ceramic powder could be increased by increasing the amount of iron chloride solution added, and in this case, some of the blue region of visible light and ultraviolet light were remarkably absorbed. When potassium acetate was added, the decomposition of the Zn(OH)₄^2- anion in the solution was promoted to facilitate the growth of ZnO crystal in the form of a barrier wall in the vertical direction on the (0001) plane, which could increase UV absorption by providing more opportunities. By controlling the amount of iron chloride solution and potassium acetate solution added, the composition and shape of the thin film plate-shaped artificial calamine ceramic powder can be optimized, and when applied to cosmetic formulations, the light transmittance of the blue region can be greatly reduced.

• 한국노년학
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• v.37 no.2
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• pp.497-516
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• 2017

This study explored the meaning and essential structure of the life of 12 older wage earners who are 65 years old or older residing in Seoul. For the in-depth analysis of the qualitative interviews, Giorgi(2012)'s phenomenological research method was used. Results presented a total of 349 meaning units, 35 core meanings, 16 emerging themes, and 6 essential themes. These essential themes consisted of a life tolerating contempt and prejudice, the hungry belly in the later years, a yoke of the subordinate, an unclimbable vertical wall, reviving the hours of youth through working, and labor pride. These six essential themes led to the essential structure of'small happiness that is felt at times out of the weary working life in later years. The research participants felt worn out by the social discrimination and unfair working conditions against older wage earners, but they felt relieved that they were able to work in old age and had a sense of self-esteem through their work. Working was the important tools for older wage earners to experience happiness in later years because it not only relieved their financial burden but also brought a sense of self-esteem and labor pride. Based on the results, we suggested as following: 1) with respect to social discrimination and unfair working conditions against older workers, the whole society should discuss it as the protection of human rights and take legal actions; 2) various service jobs need to be created so that older workers can contribute to the society by utilizing their experiences; and 3) educational programs of computer or internet use must be expanded through which older wage earners can improve their job skills.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.32 no.6
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• pp.434-445
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• 2020

In this study, the minimization of harbor oscillation using permeable breakwater was applied to the actual harbor and investigated an effect of minimization by computer simulation in order to take into account the water quality problems and measures of harbor oscillation by infragravity waves at the same time. The study site is Mukho harbor located at East coast of Korea that harbor oscillation has been occurred frequently. The infragravity waves obtained by analyzing the observed field data for five years focused on the distribution between wave periods of 40 s and 70 s and wave heights in less than 0.1 m was 94% of analyzing data. The target wave periods was 68.0 s. The most effective method of minimization of harbor oscillation by infragravity waves was to install a detached permeable breakwater with transmission coefficient of 0.3 on the outside harbor and replace some area of the vertical wall in the harbor with wave energy dissipating structure to achieve a reflectivity of 0.9 or less. The amplitude reduction rate of this method shown in 27.4%. And the effect of the difference in transmission coefficient of permeable breakwater on the reduction rate of the amplitude was not significant.

• Journal of the Korean Society of Floral Art and Design
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• no.44
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• pp.3-31
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• 2021

To verify the types of effects that plants have in our general living conditions, I examined an air quality in living rooms of the three, 129.78m² size, apartments that were with and without plants. and the findings of the study were as addressed below. 1) Experiments showed no statistically significant differences in Case A. However, in Case B and Case C, the standard deviation of PM10, PM2.5 and PM 1.0 verified that each had statistically significant (p<.01) differences. 2) It is believed that the effect of reducing particle matters due to the installation of plants in the indoor space is to vary significantly depending on the indoor environmental conditions, the cleanliness of the room, and the amount of furniture and may also differ depending on the daily dietary cooking method. In addition, it is believed that the planterior will not only reduce indoor fine dust, but also reduce the psychological comfort and eye fatigue of the residents. Nevertheless, supplementary research is needed. 3) In the planterior design for reducing indoor particle matters, various measures were examined. Among them, the vertical wall design method was tested and suggested through empirical experiments. In addition, maintenance methods were proposed depending on the type of indoor plant.

• Journal of the Korean Society of Marine Environment & Safety
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• v.28 no.7
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• pp.1259-1266
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• 2022

Recently, due to the specialization of structural design standards and evaluation methods, the classification rules are being integrated. A good example is the common international rules (CSR). However, detailed regulations are presented only for the cargo hold area where the longitudinal load is greatly applied, and no specific evaluation guidelines exist for the bow and stern structures. Structural design of the mentioned area is carried out depending on the design experience of the shipbuilder, and because no clear standard exists even in the classification, determining the root cause is difficult even if a structural damage problem occurs. In this study, an engineering-based solution was presented to identify the root cause of representative cases of buckling damage that occurs mainly in the stern. Buckling may occur at the panel wall owing to hull girder bending moment acting on the stern structure, and the plate thickness must be increased or vertical stiffeners must be added to increase the buckling rigidity. For structural strength verification based on finite element analysis modeling, reasonable solutions for load conditions, boundary conditions, modeling methods, and evaluation criteria were presented. This result is expected to be helpful in examining the structural strength of the stern part of similar carriers in the future.

• Journal of the Korean Geotechnical Society
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• v.26 no.6
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• pp.29-38
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• 2010

Micro-piles have been used to increase the bearing capacity or to restrain settlement of existing shallow foundation. Recently, micro-piles are used to support the shallow foundation, to stabilize the slope and to resist the sliding of retaining wall. Using the micro-piles in geotechnical engineering, some investigators have studied the effective installing method by model test or field test. But most of previous studies are chiefly focused on the micro-piles in sand or clay layer. If a rock layer exists in soil, the installing length of micro-piles may be determined by the depth of rock layer. In this case, the stiffness of pile may be changed by the installing length of pile, and so the installing method has to be altered by the changed stiffness of pile. Model tests have been conducted to study the installation method of micro-pile in soil with rock layer. As a result, when the ratio of length of pile is below 50 ($L/d{\leq}50$), installing of micro-piles in vertical position is effective regardless of the depth of rock layer. If the depth of rock layer is deeper than soil failure zone and the ratio of the length of pile exceeds 50 (L/d>50), installing of the micro-piles in sloped position is effective.

• Nuclear Engineering and Technology
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• v.56 no.3
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• pp.803-811
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• 2024

Nuclear accidents such as Fukushima Daiichi have highlighted the potential of passive safety systems to replace or complement active safety systems as part of the overall prevention and/or mitigation strategies. In addition, passive systems are key features of Small Modular Reactors (SMRs), for which they are becoming almost unavoidable and are part of the basic design of many reactors available in today's nuclear market. Nevertheless, their potential to significantly increase the safety of nuclear power plants still needs to be strengthened, in particular the ability of computer codes to determine their performance and reliability in industrial applications and support the safety demonstration. The PASTELS project (September 2020-February 2024), funded by the European Commission "Euratom H2020" programme, is devoted to the study of passive systems relying on natural circulation. The project focuses on two types, namely the SAfety COndenser (SACO) for the evacuation of the core residual power and the Containment Wall Condenser (CWC) for the reduction of heat and pressure in the containment vessel in case of accident. A specific design for each of these systems is being investigated in the project. Firstly, a straight vertical pool type of SACO has been implemented on the Framatome's PKL loop at Erlangen. It represents a tube bundle type heat exchanger that transfers heat from the secondary circuit to the water pool in which it is immersed by condensing the vapour generated in the steam generator. Secondly, the project relies on the CWC installed on the PASI test loop at LUT University in Finland. This facility reproduces the thermal-hydraulic behaviour of a Passive Containment Cooling System (PCCS) mainly composed of a CWC, a heat exchanger in the containment vessel connected to a water tank at atmospheric pressure outside the vessel which represents the ultimate heat sink. Several activities are carried out within the framework of the project. Different tests are conducted on these integral test facilities to produce new and relevant experimental data allowing to better characterize the physical behaviours and the performances of these systems for various thermo-hydraulic conditions. These test programmes are simulated by different codes acting at different scales, mainly system and CFD codes. New "system/CFD" coupling approaches are also considered to evaluate their potential to benefit both from the accuracy of CFD in regions where local 3D effects are dominant and system codes whose computational speed, robustness and general level of physical validation are particularly appreciated in industrial studies. In parallel, the project includes the study of single and two-phase natural circulation loops through a bibliographical study and the simulations of the PERSEO and HERO-2 experimental facilities. After a synthetic presentation of the project and its objectives, this article provides the reader with findings related to the physical analysis of the test results obtained on the PKL and PASI installations as well an overall evaluation of the capability of the different numerical tools to simulate passive systems.

• The korean journal of orthodontics
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• v.33 no.4 s.99
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• pp.293-305
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• 2003

The pharynx have significant locations and functions because it forms a part of the unit in which respiration and deglutition are carried out. Because of the closed relationship between the pharynx and the dentofacial and craniofacial structure, many studies are carried out on this subjects. The purpose of this study were to compare the airway size including pharynx, soft palate, tongue and hyoid bone between normal and hyperdivergent skeletal pattern and to evaluate the change of those size in different age. The sample of this study were consisted of 51 subjects in normal group, 52 subjects in hyperdivergent group. Each was divided into two subgroups by age , child group(9-l2yr old) and adult group(18yr old over). The lateral cephalometric radiographs were taken and the distance, angle and ratio of the facial skeleton, pharynx, soft palate, tongue and hyoid bone were measured and evaluated statistically. The result obtained were summarized as follows : 1 SN-Mn angle, FMA, and Pal-Mn angle were significantly larger in child group than adult group, but the lower anterior facial height(LAFH) and facial height ratio(FHR) were significantly smaller in child group than adult group. Occlu-Mn angle was significantly steep in hyperdivergent group than normal, but not significantly different between child group and adult group. 2. Hyperdivergent group and child group had the stronger correlation between SN-Mn angle, FMA, Pal-Mn angle, LAFH and FHR and airway size than normal group and adult group. Hyperdivevgent child group had significant negative correlation between SN-Mn angle, FMA, Pal-Mn angle and sagittal skeletal dimension of nasopharynx and sagittal depth of nasopharyngeal lumen. Significant positive correlation were seen between LAFH and vertical measurement of airway. 3. There was no difference of the linear measurement of airway size between hyperdivergent group and normal group. 4. Adult group had smaller posterior pharyngeal wall, target nasopharyngeal depth longer nasopharyngeal height and longer pharyngeal length than child group. 5. The sagittal measurement of hyoid bone had no difference between child group and adult group. But adult group had larger vertical measurement of hyoid bone than child group.