• Journal of the Korea Institute of Building Construction
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• v.19 no.6
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• pp.477-484
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• 2019

The purpose of this study is to present basic data for developing concrete with EMP shielding as the structure materials when constructing an EMP shielded building structure. In order to use metal-based recycled aggregates with excellent conductivity and easy procurement for EMP shielding concrete, an evaluation of the stability evaluation and EMP shielding performance was performed. Through the stability evaluation, it was found that the coarse aggregate stability criterion was satisfied, but the oxidized slag did not satisfy the fine aggregate stability criterion, the oxidized slag is not satisfied. In addition, as a result of fresh concrete, the workability is increased and the air volume is decreased. The compressive strength is increased due to the high density and coarse granularity of the recycled aggregates, which increased the cement paste and adhesion, thereby increasing the compressive strength. The results of an EMP shielding test show that aggregates with high shielding performance are electronic arc furnace(EAF) Oxidizing Slag and Cooper Slag. The shielding performance is expected to increase if the average particle size of aggregate is small or uniformly distributed.

• Journal of the Earthquake Engineering Society of Korea
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• v.11 no.5
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• pp.33-47
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• 2007

In a practical engineering, the equivalent static analysis (E.S.A) and the response spectrum analysis (R.S.A) are generally used for the seismic analysis. The base shears obtained from the E.S.A are invariable no matter how the principal axes of building structures are specified on an analysis program while those from the R.S.A are variable. Accordingly, the designed member size may be changed by how an engineer specify the principal axes of a structure when the R.S.A is used. Moreover, the base shears in the normal direction to the excitation axis are sometimes produced even when an engineer performs a response spectrum analysis in only one direction. This tendency makes the base shear, which is used to calculate the scale-up factor, relatively small. Therefore the scale-up factor becomes larger and it results in uneconomical member sizes. To overcome these disadvantages of the R.S.A, an alternative has been proposed in this study. Three types of example structures were adapted in this study, i.e. bi-direction symmetric structure, one-direction antisymmetric structure and bi-direction antisymmetric structure. The seismic analyses were performed by rotating the principal axes of the example structures with respect to the global coordinate system. The design member forces calculated with the scale-up factor used in the practice were compared with those obtained by using the scale-up factor proposed in this study. It can be seen from this study that the proposed method for the scale-up factor can provide reliable and economical results regardless of the orientation of the principal axes of the structures.

• Journal of Korea Water Resources Association
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• v.54 no.12
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• pp.1285-1294
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• 2021

In recent years, as rainfall is concentrated and rainfall intensity increases worldwide due to climate change, the scale of flood damage is increasing. Rainfall of a previously unobserved magnitude falls, and the rainy season lasts for a long time on record. In particular, these damages are concentrated in ASEAN countries, and at least 20 million people among ASEAN countries are affected by frequent flooding due to recent sea level rise, typhoons and torrential rain. Korea supports the domestic flood warning system to ASEAN countries through various ODA projects, but the communication network is unstable, so there is a limit to the central control method alone. Therefore, in this study, an artificial intelligence-based flood prediction model was developed to develop an observation station that can observe water level and rainfall, and even predict and warn floods at once at one observation station. Training, validation and testing were carried out for 0.5, 1, 2, 3, and 6 hours of lead time using the rainfall and water level observation data in 10-minute units from 2009 to 2020 at Junjukbi-bridge station of Seolma stream. LSTM was applied to artificial intelligence algorithm. As a result of the study, it showed excellent results in model fit and error for all lead time. In the case of a short arrival time due to a small watershed and a large watershed slope such as Seolma stream, a lead time of 1 hour will show very good prediction results. In addition, it is expected that a longer lead time is possible depending on the size and slope of the watershed.

• Journal of Environmental Health Sciences
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• v.33 no.6
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• pp.506-512
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• 2007

This study was conducted to describe the exposure levels of welding fumes by the type of manufacturers, work process, welding type and the size of manufacturers, and to find out the trend of chronological changes of airborne welding fume levels. The subjects of this study were 509 manufacturers, consisting of 11 types of manufacturers, 3 work processes, 7 welding types, in Busan from January, 1997 to December, 2005. Airborne concentration of welding fume was determined by manual of National Institute for Occupational Safety and Health (NIOSH), and the data were analyzed by using SPSS 10.0 for Windows program. The mean concentration of airborne welding fume in all manufacturers was $1.29\;mg/m^3$ (Range: $0.01{\sim}3.00\;mg/m^3)$. The level of welding fume was the highest, as $1.96\;mg/m^3$, for manufactures of motor vehicles, trailers and semi-trailers, which was lower than $5.0\;mg/m^3$ of 8 hr-TWA in Korean permissible exposure limit for welding fume. There was a significant difference in the mean levels of welding fumes by work process, showing the highest in welding workshop ($1.39\;mg/m^3$), followed by pipeline welding workshop ($1.26\;mg/m^3$) and engineering workshop ($1.20\;mg/m^3$). Among welding types, the mean level of welding fume was the highest in the type of $CO_2$ & arc welding, as $1.46\;mg/m^3$, followed by $CO_2$ welding ($1.40\;mg/m^3$), shielded metal arc welding ($1.31\;mg/m^3$), spot welding ($1.27\;mg/m^3$), and so on. The highest mean level of welding fume was $1.58\;mg/m^3$ in work process of pipe line welding workshop for the manufacturers of basic iron and steel, and $2.27\;mg/m^3$ in the type of arc welding for the manufactures building ship and boats. By the size of manufacturers, the mean concentration of welding fume for manufactures in small scale with less than 50 workers was the highest as $1.45\;mg/m^3$ (Range: $0.07{\sim}3.00\;mg/m^3)$. The mean level of welding fume was the highest as $1.39\;mg/m^3$ both in 1997 and in 2005, showing a trend of fluctuating periodically within a range of $1.10{\sim}1.39\;mg/m^3$. The above results suggested that more effective control program for work environment producing welding fumes should be developed and applied since there were significant variations in welding fume levels by the type of manufacturers, work processes, welding types, the size of manufactures, and by year.

• Journal of the Korean housing association
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• v.26 no.2
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• pp.111-119
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• 2015

This study aims to analyze space planning of accommodations in seven closed schools involved in experiential activity programs on Jeju Island, a famous tourist destination in Korea. The results are as follows. First, 35 schools had been closed down in Jeju between 1982 and 2015. Among them, four closed schools were sold, three are currently used by the Jeju special self-government provincial office of education, and 25 are being leased by individuals, village organizations, and other entities. However, they have not been well-operated, and so strategies for the effective management or operation of these closed schools should be developed. Second, there are distinctive differences in space planning of accommodations based on the correlation between experiential activities and the types of participants. If the experiential activity participants are mainly individuals or small groups, the closed school is likely to plan double-bed accommodations and individual bathrooms rather than large group rooms. Third, in order to operate experiential activity programs, closed schools require four different spaces for experiential activities, lodging, dining, and sanitation. The largest space available in each school building is used for experiential activities, and original classrooms are still in use. According to the standard drawing of school architecture, standard classroom size since 1997 has been $7.5{\times}9$ meters, and lodging rooms have mainly been re-planned based on the module of the standard-sized classroom. School cafeterias are utilized as dinning and kitchen spaces. For sanitation purposes, original school restrooms are still used by experiential program participants, while the shower rooms are newly equipped.

• Proceedings of the KSR Conference
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• 2011.10a
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• pp.297-302
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• 2011

Railway construction in the random vibration natural phenomena, as well as a relatively regular train loads for dynamic loads, such as a usability and safety should be ensured. Vibration due to train loads and seismic vibrations caused by wind compared to the typically very small in size, rather than the safety of the structure affects the usability. Recently in the downtown area, ground and underground facilities, such as a permanent facility that may cause excessive vibration increases, associated with the construction of these transportation facilities on ground vibrations of structures has been increasing concern and complaint. More recently, high-speed train vibration and noise due to furnace is increasing. In order to solve this problem, such as soundproof considering several feet, but by applying the vibration and noise reduction measures insufficient for the study is Free. In this study, track structure, track, and the inside of the building to support the system, the different forms of neurological history and share about the history cheonanahsan high-speed rail, if passed by the bus stop on the train loads of noise, and the history of interior noise and vibration measurement / analysis of measurement results to assess the relative comparison with the relevant provisions were reviewed. Based on this history, future plans for the design of the bridge to reflect the results of a study is intended to provide information. Waiting for the analysis of vibration and noise reduction, cheonanahsan history passed quietly in the train, on average, appeared to 67.53dB and 65.41dB nervous week on average, were measured with the history. Nervous week waiting room of history and the history cheonanahsan radically different shapes and sizes, so a direct comparison is impossible, but the vibration caused by the disc on the base of the polyurethane elastomer disk is not supported by GERB SYSTEM Waiting more effective in reducing the noise level considered in The main materials for railway and for the localization will help to ensure affordability is considered.

• KIPS Transactions on Software and Data Engineering
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• v.2 no.6
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• pp.433-442
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• 2013

A set of bilingual terms is one of the most important factors in building language-related applications such as a machine translation system and a cross-lingual information system. In this paper, we introduce a new approach that automatically extracts candidates of English-Korean bilingual terms by using a bilingual parallel corpus and a basic English-Korean lexicon. This approach can be useful even though the size of the parallel corpus is small. A sentence alignment is achieved first for the document-level parallel corpus. We can align words between a pair of aligned sentences by referencing a basic bilingual lexicon. For unaligned words between a pair of aligned sentences, several assumptions are applied in order to align bilingual term candidates of two languages. A location of a sentence, a relation between words, and linguistic information between two languages are examples of the assumptions. An experimental result shows approximately 71.7% accuracy for the English-Korean bilingual term candidates which are automatically extracted from 1,000 bilingual parallel corpus.

• KIEAE Journal
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• v.11 no.5
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• pp.119-127
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• 2011

The aging population has been increasing in Korea so that it is difficult for people to understand the change of the future society. This study aimed to analyze the characteristics of preliminary retiree's alternative housing preference by providing an accurate information about residential current issues and the seriousness brought by the aging society. It explained the visual information about the aspect of the residential change due to the aging society to 104 preliminary retirees who live in the apartment in Seoul. It surveyed the characteristics of the alternative housing preference following 4 situations of the Old age type(couple/healthy, couple/ill, single/healthy, single/ill). It analyzed the difference of housing preference before and after providing information. The results are as follows: First, a previous apartment is not enough to prepare the aging society and UIBS(unit insertion building system) for the elderly was expected to be a great help to the frail after 2026. Second, the preference of UIBS was increased after providing information of the aging society. Third, in the case of the illness, a big city with medical facilities was preferred not to move in the suburb. Fourth, after providing information, a small size of apartment was preferred but the preferred change of housing ownership was not founded. Last, there was considerable difference before and after providing information under 4 situation of Old age type. These results showed the feasibility of coping with more accurate future society only if a survey should be taken with providing sufficient information about the aging society.

• Proceedings of the Korean Vacuum Society Conference
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• 2012.08a
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• pp.376-376
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• 2012

Semiconductor nanowires (NWs) are future building block for nano-scale devices. Especially, Ge NWs are fascinated material due to the high electrical conductivity with high carrier mobility. It is strong candidate material for post-CMOS technology. However, thermal stability of Ge NWs are poor than conventional semiconductor material such as Si. Especially, when it reduced size as small as nano-scale it will be melted around CMOS process temperature due to the melting point depression. Recently, Graphene have been intensively interested since it has high carrier mobility with single atomic thickness. In addition, it is chemically very stable due to the $sp^2$ hybridization. Graphene films shows good protecting layer for oxidation resistance and corrosion resistance of metal surface using its chemical properties. Recently, we successfully demonstrated CVD growth of monolayer graphene using Ge catalyst. Using our growth method, we synthesized Ge/graphene core/shell (Ge@G) NW and conducted it for highly thermal stability required devices. We confirm the existence of graphene shell and morphology of NWs using SEM, TEM and Raman spectra. SEM and TEM images clearly show very thin graphene shell. We annealed NWs in vacuum at high temperature. Our results indicated that surface melting phenomena of Ge NWs due to the high surface energy from curvature of NWs start around $550^{\circ}C$ which is $270^{\circ}C$ lower than bulk melting point. When we increases annealing temperature, tip of Ge NWs start to make sphere shape in order to reduce its surface energy. On the contrary, Ge@G NWs prevent surface melting of Ge NWs and no Ge spheres generated. Furthermore, we fabricated filed emission devices using pure Ge NWs and Ge@G NWs. Compare with pure Ge NWs, graphene protected Ge NWs show enhancement of reliability. This growth approach serves a thermal stability enhancement of semiconductor NWs.

• Korean Journal of Agricultural Science
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• v.43 no.4
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• pp.670-677
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• 2016

The $6^{th}$ industrialization of agricultural areas, which is the strategy to combine the 2nd industry and the 3rd industry with the 1st industry, is one of the main policy strategies of the inistry of agriculture, food and rural affairs in Korea. This policy strategy focuses on the promotion of small- and medium-size farmers or business firms including agricultural management organizations. Even though various policy programs have been implemented for the $6^{th}$ industrialization of agricultural areas, many agricultural management organizations still claim problems. The purpose of this paper is to analyze the actual conditions of policy programs for the $6^{th}$ industrialization of agricultural areas and to suggest a development plan for the $6^{th}$ industrialization policy for agricultural producers. Especially, we focus on the point of view of agricultural management organizations in Chungnam region. The results of this study present some findings as follows: first, the $6^{th}$ industrialization policy in the agricultural area needs to aim at improving software systems, including human resource systems. Second, the policy programs should focus on improving resident's welfare through building more public facilities and amenities. Third, a strategy of selection and a focus on long-term programs are required to increase the efficiency of policy programs for the $6^{th}$ industrialization of agricultural areas.