• Journal of the Korea Concrete Institute
• /
• v.26 no.3
• /
• pp.315-321
• /
• 2014

Concrete as a construction material is widely used in nuclear vessel and plant for excellent radiation shielding. However the isolation characteristics in concrete may affect adversely in the case of fire and melt-down in nuclear vessel since temperature cooling down is very difficult from outside. This study is for development of high thermal conductive concrete, and its mechanical and thermal properties are evaluated. Magnetite aggregates with volume ratio of 42.3% (maximum) and steel powder of 1.5% are replaced with normal aggregates and thermal properties are evaluated. Thermal conductivity little increases by 30% addition of magnetite but rapidly increases afterwards. Finally thermal conductivity is magnified to 2.5 times in the case of 42.3% addition of magnetite. Steel powder has a positive effect on high thermal conduction to 106~113%. Several models for thermal conduction like ACI, DEMM, and MEM are compared with test results and they are verified to reasonably predict the thermal conductivity with increasing addition of magnetite aggregates and steel powder.

• Journal of Korean Society of Steel Construction
• /
• v.9 no.3 s.32
• /
• pp.341-350
• /
• 1997

The objective of this study is to investigate the structural behavior of the composite slabs with the new metal deckplate. The new deckplate can be used as structural member with topping concrete. So several experiments of this structural test and the fire resistance test were done. From this experiments. slabs with new metal deckpklate were verified as composite slabs. In this paper, this verifications were compared with the international design methods. For experiment. 49 specimens were made. the main parameters are deckplate thickness (1.2mm. 1.6mm) depth of topping concrete(85mm. 90mm). support condition(simple, 2-span), shear reinforcment(studs), span(2.7m, 3.0m, 3.3m. 3.6m. 3.9m) and shear span(L/3, L/4, L/7). We analyzed the structural behavior of composite slab throughout the moment-curvature relationship which is obtained with the program using the computer language. Turbo C. From this development for slab system, the reinforced concrete or steel structure building may be easy, economical for construction, And informations about the structural behavior of composite slabs will be utilized to established korea standard.

• Land and Housing Review
• /
• v.7 no.4
• /
• pp.207-215
• /
• 2016

The purpose of this paper is to explore ways in the construction of Apartment-type factories in the public sector. Recently the markets of Apartment-type factories are driven by the private sector as high quality, high price and supply of in the form of office, these construction trends are different from the original aim of introduce policy of Apartment-type factories which supply production spaces in the city to small capital enterprises. We analyzed the architectural characteristics of Apartment-type factories in Korea, the prospect of their future construction trends and the survey results targeted to small enterprises. In the results of this survey, we grope for the direction for construct Apartment-type factories in the public sector. The Apartment-type factories constructed by the public sector are appropriate supply for manufacturing plants and sale rather than lease form to complement the private market. To optimize economically and functionally for manufacturing activities, the design space in the internal and external spaces is required in order to supply more affordable. Route design, especially considering parking, unloading and warehousing of merchandise, and logistics should be differentiated from the Apartment-type Factories constructed by private sector.

• Journal of Korean Society of Forest Science
• /
• v.104 no.4
• /
• pp.607-614
• /
• 2015

This study aims to analyze the current status of timber production operation and the effects of the forestry mechanization projects on timber production. In order to increase the domestic timber production, it is necessary to propel forestry mechanization project, improve policy and institution, broaden forest-road network, enlarge the number of forest workers, enhance timber production and supply system, provide forestry machines, establish forest operation system, and train forest workers. In addition, the reestablishment of policy goals, the consistency of policy, and the rearrangement of laws and institution are considered more important. To improve the results and effects of forestry mechanization project, it is necessary to drive of forestry mechanization project, the spread of forestry machines, the cultivation of trainer ability, the development of training materials, and the teaching of field skill. In order to meet timber buyersí preference, timber needs to be produced through whole tree logging operation system. Expanding the proportion of domestic timber among total timber demand in Korea requires price competitiveness, and the supply ability of high quality product from the perspective of length and width.

• Journal of Korean Philosophical Society
• /
• v.141
• /
• pp.167-185
• /
• 2017

Chu Hsi inherited the proposition of Cheng Yi, and it spent him over ten years to finish writing the works of Xi Ming Jie, thus, making the thought of "Li Yi Fen Shu" bethe explanatory model of Xi Ming, therefore, playing the role to determine the tone of Xi Ming. At first, the thought of "Li Yi Fen Shu is a concept to embody the ethical significance of Xi Ming. But in terms of all the discussion about "Li Yi Fen Shu" of Chu Hsi in his life, this proposition is not only for the ethical significance of Xi Ming, but also includes much more general philosophical significance, revealing the general and special relationship of things. The former is the narrow "Li Yi Fen Shu", but the latter is the generalized one. This article won't discuss the generalized one, and it will take the narrow one as the research object. In the past research in academic circles, some scholars thinks that the proposition of "Li Yi Fen Shu" accords with the aim of Xi Ming, some others don't think so. Contrary to both of the two views, this article thinks that there is some conformity and inconformity between the explanatory model of "Li Yi Fen Shu" of Chu Hsi and the aim of Xi Ming. In other words, Contributions and limitations coexist when Chu Hsi explains Xi Ming in the model of "Li Yi Fen Shu", and there is not only the development to the intention of Xi Ming, but alsothe far meaning away from the aim of Xi Ming.

• Journal of the Korean Crystal Growth and Crystal Technology
• /
• v.28 no.6
• /
• pp.243-249
• /
• 2018

Ceramic tiles, which were manufactured through high-temperature firing process at over $1000^{\circ}C$, are widely used as interior and exterior materials for building construction due to their excellent durability and aesthetic of surface glaze. In recent years, the introduction of digital ink-jet printing in ceramic tiles for architectural use has been rapidly proceeding, and studies on the materials such as ceramic ink, ceramic pigment, glaze have been actively conducted. In this study, the effect of microstructure change of surface glaze on the printing properties of ceramic inks was investigated by micronization of kaolin, which is the raw material of surface glaze. Black ceramic ink was used for ink-jet printing on the surface glaze of ceramic tile to evaluate the printability by measuring the size and roundness of the printed ink dot. The relationship between microstructure change of surface glaze and printability of ceramic ink was also investigated by analyzing the surface roughness and internal micropore distribution of surface glaze.

• Journal of the Korean Crystal Growth and Crystal Technology
• /
• v.29 no.5
• /
• pp.215-221
• /
• 2019

Ceramic tiles, which are widely used as interior and exterior materials for construction, have recently been required to have pollution prevention function. In order to remove contaminants, many researches of ceramic tiles with hydrophilic surface property through $TiO_2$ coating and hydrophobic surface property by improving the flow of water droplets have been proceeded. Expecially, it is very important to develop a surface glaze having hydrophobicity through a sintering process above $1000^{\circ}C$ without an additional coating process and the degradation of mechanical properties. In this study, surface glaze with copper powder was applied to manufacture of ceramic tile. Contact angle of ceramic tile according to thickness of surface glaze layer was investigated after the conventional sintering process. The contact angle of the ceramic tile surface without the copper powder was shown to be $25.3^{\circ}$, which is close to hydrophilic surface. However, the contact angle was increased up to $109.8^{\circ}$ when the thickness of surface glaze with the copper powder was $150{\mu}m$. The excellent hydrophobic property of the surface glaze with copper powder was resulted from the cellular structure of copper particles on the glaze surface. In addition, the mechanical properties of the developed hydrophobic ceramic tiles such as bending strength, chemical resistance, abrasion resistance, and frost resistance were well maintained and meet the criteria of 'KS L 1001 Ceramic tile'.

• Korean Journal of Food Science and Technology
• /
• v.48 no.3
• /
• pp.247-255
• /
• 2016

This study was performed to investigate the effect of packaging materials on quality characteristics of washed potatoes such as Hunter's a value, chlorophyll and potato glycoalkaloids (PGA) content during their storage for 15 days. Packaging methods were evaluated into five ways: no packaging (NP, positive control), paper bag (PB, negative control), onion net (ON), transparent oriented to polypropylene without hole (TP), opaque oriented polypropylene with 4 holes (OP). Hunter's a values of washed potatoes showed minus in NP and TP after 12 days storage, whereas all plus values were observed in those of PB, ON, and OP. Total chlorophyll content of washed potatoes was the highest in no packaging at 15 days after storage. The PGA content of washed potatoes showed low levels in flesh part (below $5mg/100g{\cdot}FW$) as well as in peel part ($4.5-9.3mg/100mg{\cdot}FW$) in all packagings up to 15 days after storage.

• Journal of architectural history
• /
• v.3 no.1
• /
• pp.83-99
• /
• 1994

Ch'ang-Ts'al-Ts'un is a rural Village near Lung-jing City in Yen-pien Korean Autonomous Province of China. It was formed about 100 years ago by Korean Immigrants and has been developed maintaing the characteristics of traditional Korean architecture. Therefore investigating the spatial structure of this village is a meanigful work to confirm and explore one branch of Korean architecture. This study aims at analyzing the spatial structure of the village using direct data collected from the field work and indirect data from books and maps. The field work consists of on-the-site survey of the village layout, interviews of residents, observation notes and photography. Ch'ang-Ts'ai-Ts'un is located 360-370 m high above the sea level and at the side of a long valley. A river flows in the middle of the valley and relatively flat arable land exists at the both sides of the river. The location of the village related to the surrounding river and mountains suggests that the site of the village was chosen according to Feng-Shui, Chinese and Korean traditional architectural theory. The main direction of the house layouts is South-western. The village has been growing gradually until today. Therefore it is meaningful to make the village layout before Liberation(1946 A.D.) because the characteristics of Korean architecture prevailed more in that period. The area of the previous village is limited to the west side of the creek. New houses were later added to the east of the creek, forming a 'New Village'. Previously the village was composed of 3 small villages: Up, Middle and Down. Also the main access roads connecting the village with the neighboring villages were penetrating the village transversely. Presently the main access road comes to the village longitudinally from the main highway located in front of the village. The retrospective layout shows the existence of well-formed Territory, Places and Axes, thus suggesting a coherent Micro-cosmos. The boundary of imaginery territory perceived by present residents could be defined by linking conspicous outside places sorrounding the village such as Five-mountains, Front-mountain, Shin-dong village, Standing-rock, Rear-mountain and Myong-dong village. Inside the territory there are also the important places such as Bus-stop, Memorial tower of patriots, Road-maitenance building and the village itself. And inside it 5 transverse and 1 longitudinal axes exist in the form of river, roads and mountains. The perceived spatial structure of the village formed by Places, Axes and Territory is geometrical and well-balanced and suggests this village is fit for human settlement. The administrative area of the village is about 738 ha, 27 % of which is cultivated land and the rest is mountain area. Initially the village and surrounndings were covered with natural forest But the trees have been gradually cut down for building and warning houses, resulting in the present barren and artificial landscape with bare mountains and cultivated land. At present the area of the village occupied by houses is wedge-shaped, 600 m wide and 220 m deep in its maximum. The total area of the village is $122,175m^{2}$. The area and the rate of each sub-division arc as follow. 116 house-lots $91,465m^{2}$ (74.9 %) Land for public buildings and shops $2,980m^{2}$ (2.4 %) Roads $17,106m^{2}$ (14.0 %) Creek $1,356m^{2}$ (1.1 %) Vacant spaces and others $9,268m^{2}$ (7.6 %) TOTAL $122,175m^{2}$ (100.0 %) Each lot is fenced around with vertical wooden pannels 1.5-1.8 m high and each house is located to the backside of the lot. The open space of a lot is sub-divided into three areas using the same wooden fence: Front yard, Back yard and Access area. Front and back yards are generally used for crop-cultivation, the custom of which is rare in Korea. The number of lots is 116 and the average size of area is $694.7m^{2}$. Outdoor spaces in the village such as roads, vacant spaces, front yard of the cultural hall, front yard of shops and spacse around the creek are good 'behavioral settings' frequently used by residents for play, chatting, drinking and movie-watching. The road system of the village is net-shaped, having T-junctions in intersections. The road could be graded to 4 categories according to their functions: Access roads, Inner trunk roads, Connecting roads and Culs-de-sac. The total length of the road inside the village is 3,709 m and the average width is 4.6 m. The main direction of the road in the village is NNE-SSE and ESE-WNW, crossing with right angles. Conclusively, the spatial structure of Ch'ang-Ts'ai-Ts'un village consists of various components in different dimensions and these components form a coherent structure in each dimension. Therefore the village has a proper spatial structure meaningful and appropriate for human living.

• Journal of Korean Society of Forest Science
• /
• v.73 no.1
• /
• pp.14-20
• /
• 1986

The processing times of the works, chainsaw felling, axe trimming and hand skidding to the corridor, by one-man-work method per single pole timber were investigated in the thinning young Japanese larch stand at the Training Forests of the Forest Work Tranining Center in Kangwon-do. The works were performed by a skilled worker with the craftman qualification and 69 trees were cut. Time was checked at intervals of 25/100 minute by the multimoment method and the worker's efficiency was evaluated for every cycle. Total working time was 8.11 hours of which 90% was for thinning work and 10% for cleaning work. Of the total working hours, 82.7% was net working time, 12.3% was general working time and 4.9% was non-valuated time. Of the net working time, 5.9hours, for only thinning, 20.9% was spent on moving to the feeling tree, 27.1% was spent on felling, 40.5% was spent on trimming and 11.5% was spent on skidding to corridor. Net chainsaw operating time was 0.94 hour which included 0.2 hour for cleaning work. Of the net chainsaw operating time, 0.94 hour, 66% was operating time and 34% was idle running time. The basic and general working times by DBH classes with application of 130% worker's efficiency calculated from regression equations were shown in table 1. For better practical using of this table, the simplified proposal was given in table 2.