• Journal of Korean Society of Environmental Engineers
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• v.32 no.12
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• pp.1126-1133
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• 2010

A two-stage biofilter was constructed and utilized to determine the removal efficiency when treating dynamic loading of a mixture of odorous compounds including benzene, toluene, p-xylene, ammonia and hydrogen sulfide. A yeast strain, Candida tropicalis, and a sulfur oxidizing bacterial (SOB) strain, Acidithiobacillus caldus sp., were immobilized in polyurethane media and packed in the two-stage biofilter. The experiment of dynamic loading variation was composed of (1) stepwise loading variation of all the odorous compounds (total EC test), (2) stepwise loading variation of each odorous compound, and (3) intermittent loading variation with 2-day-off and 3-day-on. The total EC test showed that the maximum elimination capacity was $61\;g/m^3/hr$ for total VOCs, and 5.2 and $9.1\;g/m^3/hr$ for ammonia and hydrogen, respectively. In addition, the inhibition between VOCs was observed when the loading of each individual VOC was varied. Especially the stepwise increase in toluene loading resulted in decreases of benzene and p-xylene removal efficiencies about 30% and 25%, respectively. However, the inhibition between organic and inorganic compounds was not observed. The intermittent loading variation with 2-day-off and 3-day-on showed that greater than 95% of the overall removal efficiency was restored in two days after the loading resumed. Consequently, the two-stage biofilter packed with immobilized microorganisms showed advantages over conventional biofilters for the simultaneous treatment of the mixture of organic and inorganic odorous compounds.

• Journal of Korean Society of Environmental Engineers
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• v.27 no.3
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• pp.253-261
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• 2005

Catalytic wet oxidation of ppm levels of trichloroethylene (TCE) in water has been conducted using $TiO_2$-supported cobalt oxides at a given temperature and weight hourly space velocity. 5% $CoO_x/TiO_2$ might be the most promising catalyst for the wet oxidation at $36^{\circ}C$ although it exhibited a transient behavior in time on-stream activity. Not only could the bare support be inactive for the wet decomposition reaction, but no TCE removal also occurred by the process of adsorption on $TiO_2$ surface. The catalytic activity was independent of all particle sizes used, thereby representing no mass transfer limitation in intraparticle diffusion. Characterization of the $CoO_x$ catalyst by acquiring XPS spectra of both fresh and used Co surfaces gave different surface spectral features of each $CoO_x$. Co $2p_{3/2}$ binding energy of Co species exposed predominantly onto the outermost surface of the fresh catalyst appeared at 781.3 eV, which is very similar to the chemical states of $CoTiO_x$ such as $Co_2TiO_4$ and $CoTiO_3$. The spent catalyst possessed a 780.3 eV main peak with a satellite structure at 795.8 eV. Based on XPS spectra of reference Co compound, the TCE-exposed Co surfaces could be assigned to be in the form of mainly $Co_3O_4$. XRD measurements indicated that the phase structure of Co species in 5% $CoO_x/TiO_2$ catalyst even before reaction is quite comparable to the diffraction lines of external $Co_3O_4$ standard. A model structure of $CoO_x$ present on titania surfaces would be $Co_3O_4$, encapsulated in thin-film $CoTiO_x$ species consisting of $Co_2TiO_4$ and $CoTiO_3$, which may be active for the decomposition of TCE in a flow of water.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.12
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• pp.496-503
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• 2016

To analyze an infinite slope that is reinforced with stabilizing piles, the forces on the stabilizing pile were estimated by the theory of plastic deformation and the theory of plastic flow and the effects of diverse factors on the factor of safety of an infinite slope were investigated. According to the results of the analyses, the factor of the safety of the slope reinforced with stabilized piles were increased tremendously and the factor of safety decreased as the center to center distance of the stabilizing pile increased. The effect of the existence of seepage of the infinite slope with stabilizing piles on the factor of safety appears to be insignificant. Considering the formulated factor of safety of an infinite slope with stabilizing piles, the width and length of the element of the infinite slope and force on the stabilizing pile influence the factor of safety of the infinite slope with a stabilizing pile including the soil strength parameter, inclination of the slope and depth of the slope, which are important for calculating the factor of safety of a non-reinforced infinite slope. The factor of safety of an infinite slope with stabilizing piles derived from the theory of plastic deformation were increased significantly with the internal friction angle of the soil, and the minimum and the maximum factor of safety under the conditions considered in this study were 13.7 and 65.6, respectively. As the diameter of the stabilizing pile increased, the forces on the stabilizing pile also increased but the factor of safety of the infinite slope with stabilizing piles decreased due to the effects of the width and the length of the element of the infinite slope. The factor of safety of the infinite slope with stabilizing piles derived from plastic flow were much larger than that of the non-reinforced infinite slope and the factor safety of the infinite slope with a stabilizing pile increased with increasing product of the flow velocity and plastic viscosity ( ) and the factor of safety of the infinite slope with stabilizing piles decreased with increasing center to center distance of the pile.

• Journal of Science of Art and Design
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• v.5
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• pp.175-216
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• 2003

시각이 아닌 오감체계에 관계하는 때문에 현대미술은 외관만으로 이루어지지 않는다. 곧 예술 작품들은 하나의 장소를 관객에게 제공하여, 심리적, 물리적, 또는 예술이 존재여부에 관한 갖가지 질문들을 제기한다. 모든 예술 작품은 메시지를 담고 있다. 이러한 관점에서 개념 또는 아이디어에 우선하는 현대미술은 그들의 메시지를 전달하기 위해 우리의 사회적 배경과 보편성을 간과할 수 없다. 우리의 물체 인식은 결국 우리의 경험체계를 통해서 이루어진다고 간주하면, 현대미술의 새로운 형태는 보편적 특질들이 그 특질들 이상의 상태로 보여지도록 유도한다. 이러한 창조 행위의 시작은 현대인간의 문화 읽기이며 문화는 인간과 자연의 긴밀한 관계 속에서 이루어진다. 역사는 지나간 시간을 기록한 것이며, 이 또한 우리의 지식과 정보 체계에 속한다. 회화가 평면에 입체감을 표현하는 것과는 달리 조각은 자연 속, 즉 실재공간 속에 있는 모든 것을 표현하기 때문에 시각(visible) 이외에도 촉각(tangible)이 관여하게 된다. 조각의 특수성은 촉각(tangible)이 우선하는 것이다. 그러나 시각과 촉각은 매우 적극적으로 미학적 경험에 참여하는 감각으로 이들을 서로 분리하여 생각하기가 무척 힘들다. 왜냐하면 어떤 경험에 있어서 기억연합 또는 감각 연합에 의해 하나의 감각이 다른 여러 감각을 촉발하여 연쇄반응 혹은 '형태 Gestalt'를 이루기 때문이다. 대부분의 근대 조각 작품들은 조각대 위에 고정되어 있는 구상 형태를 지녔기 때문에 조각작품 자체가 지닌 외적 형태와 그 자체내의 공간이 더욱 중요한 역할을 하게 된다. 말하자면 미로의 비너스 조각은 대리석과 비너스 형태의 결합이다. 때문에 관객은 그 주변을 돌면서 우리 신체의 내적 공간과 시각에 의존하면서 그 작품의 중량감, 양감, 형태 등의 특질과 만나게 된다. 그러나 현대 추상조각과 개념조각은 이보다 좀 더 확장된 공간을 제시한다. 이것은 현대조각이 건축개념을 수용한 때문이며, 그것이 때로는 안 쪽에서 때로는 바깥 쪽에서 그 형태를 결정하며, 보고 듣고 느끼고 만져지고 왕래하는 등의 인식 영역인 관객의 오감체계에 직접적으로 관계하기 때문이다. 우리는 건축 공간에서, 시각 외에도 청각이나 촉각을 통해 지각한다. 대강 요약하자면 공간은 객관적 상태이기보다는 인식영역의 주관성을 통해 받아들여진 우리가 지나쳐온 것들이나 체험된 공간이다. 여기서 '받아들여지는' 일은 과거 경험들의 주체들, 언어와 문화에 의해서 이루어져야 한다. 건물, 즉 둘러싸고 있는 공간은 중앙이 아니다. 중앙은 바로 나, 둘러싸여진 나이다 나는 나의 동작에 따라 그 공간의 시스템을 변화시킬 수 있는 유동적인 중심이다 (이때의 나는 위치의 축을 변화시키는 것이 아니라, 그들을 탐색하는 것이다). 작품이 대형화되면서 이러한 건축공간개념이 현대 조각가들의 작품개념에 이용되었다고 본다. 현대미술에서 In situ작업과 특정한 장소를 위한 기획되어진 최근의 프로젝트 작업들은 대형화되어있으며, 건축에서처럼 특정한 장소를 만들어낸다. 로잘린드 크라우스(Rosalind Krauss)는 또한 '조각영역의 확장 (La sculpture dans le champ elargi)'에서 현대조각이 건축과 환경의 영역을 침범하고 있음을 지적한다. 그녀에 의하면, 1960년대 이후의 현대조각은 이러한 탈 귀속성과 조각의 자율성을 획득함으로써 조각은 건축물이 아니면서 건축물 주변에 위치하거나 풍경이 아니면서 풍경 안에 자리잡게 되었다. 이와 같이 현대의 대형조각 작품들 - 예를 들어 대형화된 미니별 조각이나 개념미술, 또는 대지예술 등 -은 풍경의 실재가 아니기 때문에 환경으로부터 구분된다고 언급하고 있다. 이들 조각은 더 이상 만져지는 실체이거나 점유하는 공간의 상징언어를 지닌 조각의 범주에 한정되지 않게 된다. 조각과 건축의 공간인식을 인체의 크기와 관련하여 보면, 메를로 퐁티(Merleau-Ponty)의 '지각의 현상학' 은 우리가 논하는 작품의 공간체계를 분석하는데 지침표가 되어준다. 메를로 퐁티가 말하는 지각은 정신에 의해서만 이루어지는 것이 아니며, 몸과 함께 이루어지는 현상이다. 지각은 우리가 부단히 눈을 움직이고 만지고 냄새를 맡고 주변을 돌아 다니면서 세계와의 직접적인 접촉을 통해 이루어 진다. 몸의 움직임을 통하여 나타나는 신체적 표현은 몸 자체가 원천적으로 지향적 활동의 주체로서 파악되는 한 이미 항상(恒常, constant) 의미 현상을 지니다. 우리의 지각이 움직이는 몸의 지향 활동을 통해 이루어진다는 것은 우리의 몸의 지향활동이 의식에 선행함을 의미한다. 몸의 움직임은 의식의 의도를 표현할 때에만 의미를 나타내는 기호가 되는 것이 아니라, 이미 그 자체가 살아있는 표현이다. 우리의 몸짓, 표정은 우리 의식이 의도하기 전에 이미 의미가 담겨있다. 몸은 그 자체가 기호(Signe)적이다. 결국. 메를로 퐁티에게서 세상(le monde entier)은 그 자신이 주체가 되어 인식한다, 그리고 이 인식 구조에는 우리의 몸이 구심점(le point centripete)이 된다. 만약 우리가 이러한 메를로 퐁티의 개념을 염두에 둔다면, 예술작품의 특성에 매우 중요한 역할을 하고 있는 재료와 크기를 이해할 수 있을 것이다.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.23 no.6
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• pp.449-469
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• 2011

This article reviews the papers published in the Korean Journal of Air-Conditioning and Refrigerating Engineering during 2010. It is intended to understand the status of current research in the areas of heating, cooling, ventilation, sanitation, and indoor environments of buildings and plant facilities. Conclusions are as follows. (1) Research trends of thermal and fluid engineering have been surveyed as groups of general thermal and fluid flow, fluid machinery, and new and renewable energy. Various topics were presented in the field of general thermal and fluid flow. Research issues mainly focused on the thermal reliability of axial fan and compressor in the field of fluid machinery. Studies on the design of ground source heat pump systems and solar chemical reactors were executed in the field of new and renewable energy. (2) Research works on heat transfer area have been reviewed in the categories of heat transfer characteristics and industrial heat exchangers. Researches on heat transfer characteristics included heat transfer in thermoelectric cooling/power generation systems, combined heat and power systems, carbon nano fluid with PVP, channel filled with metal foam and smoke ventilation in a rescue station of a railroad tunnel. Also the studies on flow boiling of R123/oil mixture in a plain tube bundle and R410A charge amount in an air cooled mini-channel condenser were reported. In the area of industrial heat exchangers, researches on plate heat exchanger, shell and tube heat exchanger, enthalpy exchanger, micro channel PCHE were performed. (2) Research works on heat transfer area have been reviewed in the categories of heat transfer characteristics and industrial heat exchangers. Researches on heat transfer characteristics included heat transfer in thermoelectric cooling/power generation systems, combined heat and power systems, carbon nano fluid with PVP, channel filled with metal foam and smoke ventilation in a rescue station of a railroad tunnel. Also the studies on flow boiling of R123/oil mixture in a plain tube bundle and R410A charge amount in an air cooled mini-channel condenser were reported. In the area of industrial heat exchangers, researches on plate heat exchanger, shell and tube heat exchanger, enthalpy exchanger, micro channel PCHE were performed. (3) Refrigeration systems with alternative refrigerants such as hydrocarbons, mixed refrigerants, and CO2 were studied. Performance improvement of refrigeration systems are tried applying various ideas of refrigerant subcooling, dual evaporator with hot gas bypass control and feedforward control. The hybrid solar systems combining the solar collection devices with absorption chillers or compression heat pumps are simulated and studied experimentally as well to improve the understanding and the feasibility for actual applications. (4) Research trend in the field of mechanical building facilities has been found to be mainly focused on field applications rather than performance improvements. Various studies on heating and cooling systems, HVAC facilities, indoor air environments and energy resources were carried to improve the maintenance and management of building service equipments. In the field of heating and cooling systems, papers on a transformer cooling system, a combined heat and power, a slab thermal storage and a heat pump were reported. In the field of HVAC facilities, papers on a cooling load, an ondol and a drying were presented. Also, studies on HVAC systems using unutilized indoor air environments and energy resources such as air curtains, bioviolence, cleanrooms, ventilation, district heating, landfill gas were studied. (5) In the field of architectural environment and energy, studies of various purposes were conducted such as indoor environment, building energy, renewable energy and green building. In particular, renewable energy and building energy-related researches have mainly been studied reflecting the global interest. In addition, many researches which related the domestic green building certification of school building were performed to improve the indoor environment of school.

• Journal of the Korean earth science society
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• v.39 no.3
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• pp.250-259
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• 2018

We investigated the petrological features of the stone materials used in the Jeolla Usuyeong rampart and estimated their provenance through the geological survey. The Jeolla Usuyeong was designated as a historic site (No. 535) on 2016. Since the remaining rampart is less than 15%, it is necessary to make conservation on it. In this study, we discriminated the stone materials used for the rampart according to their petrographic characteristics and estimated the volume proportion of each stone by the rock type. Also, we measured the whole-rock magnetic susceptibility. The petrographic features of the stones in the rampart were compared with those in the vicinity by their mineral composition and texture. The stone materials of the rampart mainly consist of the tuff, lapilli tuff, and lapilli stone. Among these three kinds of rocks, lapilli tuff is quantitatively the most abundant (60.3%), the next is tuff (34.7%), and lapilli stone (2.5%) shows the least amount. The whole-rock magnetic susceptibility of the tuffaceous rocks can be divided by the value of $1.0{\times}10^{-3}$ SI unit. Also, the compressive strength of tuff exhibits about 156 MPa, which is adequate to reuse for the repairing work. Petrological comparisons between stone materials and outcrop rocks distributed around the Hwawon peninsula leads to a conclusion that the stone materials of the rampart are likely to have been delivered from the Dongoeri and Sindeok-ri. Judging from the results of the comparison on the frequency of use and physical properties among the tuffaceous rocks, tuff is considered to suitable for restoring the rampart.

• Journal of the Korea Concrete Institute
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• v.16 no.1 s.79
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• pp.43-53
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• 2004

The current Korean Concrete Design Code(KCI Code) requires the minimum and maximum content of shear s in order to prevent brittle and noneconomic design. However, the required content of the steel reinforcement In KCI Code is quite different to those of the other design codes such as fib-code, Canadian Code, and Japanese Code. Furthermore, since the evaluation equations of the minimum and maximum shear reinforcement for the current KCI Code were based on the experimental results, the equations can not be used for the RC members beyond the experimental application limits. The concrete tensile strength, shear stress, crack inclination, strain perpendicular to the crack, and shear span ratio are strongly related to the lower and upper limits of shear reinforcement. In this research, an evaluation equation for the minimum content of shear reinforcement is theoretical proposed from the Wavier's three principals of the mechanics of materials.

• Journal of the Korea Concrete Institute
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• v.22 no.6
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• pp.851-858
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• 2010

In this study, waste glass and bottom ash were used as basic materials in order to secure a recycling technology of by-products which was mostly discarded and reclaimed. In addition, because softening point of waste glass is less than $700^{\circ}C$ and bottom ash includes combustible material, it was possible to manufacture low-temperature sintering lightweight aggregates for energy saving at $800{\sim}900^{\circ}C$ that it is as much as 20~30% lower than sintering temperature of existing lightweight aggregates. Thermal conductivity of newly-developed lightweight aggregates was 0.056~0.105W/m. K and its porosity was 40.36~84.89%. A coefficient of correlation between thermal conductivity and porosity was -0.97, it showed very high negative correlationship. With this, we were able to verify that porosity is key factor to affect thermal conductivity. Microstructure of lightweight aggregates by $CaCO_3$ content and replacement ratio of bottom ash in the variation of temperature were that $CaCO_3$ content increased along with pore size while replacement ratio of bottom ash increased as pore size decreased. Specially, most pores were open pore instead of closed pore of globular shape when replacement ratio of bottom ash was 30%, and pore size was small about 1/10~1/5 as compared with case in bottom ash 0~20%. In addition, open pore shapes were remarkably more irregular form of open pore in $900^{\circ}C$ than $700^{\circ}C$ or $800^{\circ}C$ when replacement ratio of bottom ash was 30%. We reasoned hereby that these results will influence on absorption increase, strength and thermal conductivity decrease of lightweight aggregates.

• Korean Journal of Construction Engineering and Management
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• v.14 no.1
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• pp.32-42
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• 2013

The Korean Government introduced a cultural heritage supervision system in January 2010 to control quality and to prevent poor construction. However, cultural heritage related constructions that require supervision, a scope of supervision, supervision cost and placement of supervisors have not been standardized yet. For this reason, standards of supervision for repair works of cultural heritage that reflect the characteristics of small-scale repair works and restoration of cultural heritage are required. Accordingly, this study has suggested standards of supervision works and cost by analyzing the average construction period that is suitable for the characteristics of cultural heritage repair works. In other words, this study has suggested standards of full-time supervision costs by applying the fixed amount-added method (adding direct labor cost, direct expenses, overhead expenses, engineering fee, charges for additional works and VAT) which is the same as the method of calculating supervision costs for public construction projects because a supervisor has to work full time at a construction site to perform supervision if the project is a mid/large-scale cultural heritage repair work. Also, this study has suggested standards of part-time supervision costs for a small-scale cultural heritage repair work and the ways of supervising the construction projects by visiting the project site on important occasions. According to the result of the analysis by applying the forgoing standards of supervision costs for cultural heritage, a full-time supervision cost for cultural heritage repair works is approximately 98% compared to the construction supervision of a public construction project, and a part-time supervision is approximately 158% compared to architectural construction supervision. It is expected that the valuable cultural heritage of Korea will be preserved by controlling quality of cultural heritage repair works through the application of this study result - the standards of supervision costs for cultural heritage repair works - to an actual project.

• The korean journal of orthodontics
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• v.28 no.2 s.67
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• pp.237-253
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• 1998

Surgical-orthodontic treatment is performed for the skeletal Class III patients with no remaining growth and too big a skeletal discrepancy (or camouflage treatment, and two jaw surgery is needed in order to have maximum effect in such patients. In two jaw surgery cases, surgical alteration of the occlusal plane is necessary to establish optimal function, esthetics and postoperative sability, therefore the establishment of the occlusal plane is essential in diagnosis and treatment. The object of this study is to evaluate the stability of the indiviual ideal occlusal plane bsaed on the architectural and structural craniofacial analysis of Delaires. Thus, the subjects of this study were 48 patients who underwent two jaw surgery, and divided in two groups. Each group were composed of 24patients, A group were operated with ideal occlusal plane and B group were not. Two groups were compared at the preoperative, immediate postoperative (average 4.3days), and long-term postoperative (average 1.3years) lateral cephalometric radiographs. The following results were obtained: 1. There was no significance in occlusal plane angulation between $T_2\;and\;T_3$. Average long term follow-up changes of occlusal Plane angle were $0.24^{\circ}{\pm}2.43$, with FH plane and $0.15{\circ}{\pm}2.16{\circ}$ with SN plane in all 48 patients. These results demonstrated that the occlusal plane after two jaw surgery in skeletal Class III malocclusion was stable. 2. There was no significance in postoperative stability of occlusal plane between A and B group. 3. There was no significance in postoperative stability of occlusal plane depending on surgeon and operative method within each group. 4. The postoperative changes of occlusal plane were correlated to the postoperative changes of jaw rather than tooth position. 5. There was no correlation between the postoperative changes of occlusal plane and maxillary impaction and mandibular setback with surgery.