• Geomechanics and Engineering
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• 제20권1호
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• pp.67-73
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• 2020

With the increasing number of underground projects, the problem of rock-water coupling catastrophe has increasingly become the focus of safety. Grouting reinforcement is gradually applied in subway, tunnel, bridge reinforcement, coal mine floor and other construction projects. At present, cement-based grouting materials are easy to shrink and have low strength after solidification. In order to overcome the special problems of high water pressure and high in-situ stress in deep part and improve the reinforcement effect. In view of the mining conditions of deep surrounding rock, a new type of cement-based reinforcement material was developed. We analyses the principle and main indexes of floor strengthening, and tests and optimizes the indexes and proportions of the two materials through laboratory tests. Then, observes and compares the microstructures of the optimized floor strengthening materials with those of the traditional strengthening materials through scanning electron microscopy. The test results show that 42.5 Portland cement-based grouting reinforcement material has the advantages of slight expansion, anti-dry-shrinkage, high compressive strength and high density when the water-cement ratio is 0.4, the content of bentonite is 4%, and the content of Nano Silica is 2.5%. The reinforcement effect is better than other traditional grouting reinforcement materials.

• 한국건설순환자원학회논문집
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• 제10권3호
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• pp.321-326
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• 2022

이 연구는 바이오매스를 원료로 사용하여 에너지화하는 열병합 발전소가 최근 전 세계적으로 많은 관심을 받고 있고 국내에서도 점차 증가하고 있는 추세에 있으며 이로 인하여 발생하고 있는 바닥재를 콘크리트용 잔골재로서 활용하기 위한 가능성을 확인하기 위하여 기초 물성 및 안정성 평가 실험을 수행하였다. 표준사 28일 기준 압축강도와 비교하여 목재칩 골재는 111 %, 표준사 56일 기준 길이변화율과 비교하여 목재칩 골재는 89 %, 폐기물공정시험 결과 폐기물관리법 시행규칙에 따른 유해물질의 기준 미만을 모두 충족하여, 열병합발전소로 인하여 발생하는 바닥재를 콘크리트용 잔골재로 활용할 수 있을 것으로 판단된다.

• 대한치과의사협회지
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• 제48권1호
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• pp.45-55
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• 2010

Purpose: The aim of this study was to evaluate 1 year cumulative survival rate of implants placed on augmented sinus using Osteon$^{(R)}$, bone graft material and to assess height of the grafted material radiographically. Material and Methods: 10 maxillary sinuses were augmented in 10 patients and 25 implant fixtures were installed simultaneously or after 6 months healing period. The height of the sinus graft material was measured using panoramic images immediately after augmentation and up to 19 months subsequently. Changes in the height of the sinus graft material were calculated with respect to implant length and original sinus wall height. Results: The cumulative survival rate was 100% in all 25 implants. Additionally, normal healing process without any complication was observed in all patients. The mean crown/Implant ratio was 1.25. The mean marginal bone loss was 0.95mm and the mean resorption rate of Osteon$^{(R)}$ was 0.05mm/month. The fastest resorption site of Osteon$^{(R)}$ is the first molar area. The grafted material was well maintained in sinus and decreased slightly over 1 year. Conclusion: In conclusion, It can be suggested that Osteon$^{(R)}$ may have predictable result when it was used as a grafting material for sinus floor augmentation.

• 대한설비공학회지:설비저널
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• 제20권2호
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• pp.110-116
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• 1991

• 한국주거학회논문집
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• 제12권4호
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• pp.219-226
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• 2001

This treatise measures and estimate sound insulation performance of apartment house. Sound insulation performance measured to the floor and wall. Measurement object is apartment occupancy ago of 100㎡ scale built to higher story in Taegu city. Floor Slav's light impact sound level interception performance interacted by benevolent person who carrying out availability of finish material important. Floor Slav's heavy impact sound level interception performance amounted estimation by being good more or less then light impact sound level interception performance. Because sound insulation performance of partition between adjoined generation is gad seldom, privacy infringement becomes anticipation. There was discussion about these results, and presented various kinds future research task to prove sound insulation performance of apartment house.

• 대한두개안면성형외과학회지
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• 제17권3호
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• pp.111-118
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• 2016

The medial wall and floor of the bony orbit are frequently fractured because of the delicate anatomy. To optimize functional and aesthetic results, reconstructive surgeons should understand the anatomy and pathophysiology of orbital fractures. Appropriate treatment involves optimal timing of intervention, proper indications for operative repair, incision and dissection, release of herniated tissue, implant material and placement, and wound closure. The following review will discuss the management of orbital floor fractures, with the operative method preferred by the author. Special considerations in operation technique and the complication are also present in this article.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2001년도 추계학술대회논문집A
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• pp.815-820
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• 2001

According as industry is complex, architecture is changing into the complex and diverse style and also customer's demands are becoming diversified. Among these, a door field is very important as much as saying nothing of more explanation. In this paper, in order to develop large floor hinge, mechanical properties of component parts are measured by vickers hardness tester, microstructure analysis and at the same time, these are designed by the FEM analysis.

• 한국에너지공학회:학술대회논문집
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• 한국에너지공학회 1995년도 춘계학술발표회 초록집
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• pp.213-222
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• 1995

Korean traditional Ondol with the sensible heat storage medium has been for a long time used as residential heating system, in these days the concrete Ondol without the heat storage medium was realized as the heating system in the private houses and the apartments. This floor heating system is good for our health. But the concrete Ondol is not desirable for the energy saving and for the maintenance of comfortable room temperature because the heat storage medium is not employed in the concrete Ondol. And as the hot water circulating pipes ate buried under the the concrete floor, the concrete Ondol system has some kind of problems to be improved. Therefore the new type of Ondol system was developed in this study. And the new Ondol was consisted of latent heat storage material as heat storage medium with a great heat capacity and bioceramics as medium to maintain comfortable room temperature. In this study, the heat transfer characteristics of latent heat storage-bioceramic Ondol was analyzed theoretically.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2005년도 추계학술대회논문집
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• pp.377-380
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• 2005

Damping materials encompass a broad range of materials, including, but not limits to, pressure sensitive adhesives, epoxies, rubbers, foams, thermoplastics, enamels and mastics. Their common characteristic is that their modulus is represented by a complex quantity, possessing both a stored and dissipative energy component. Loss factor of damping material analyzed more than 2 times than rubber to 1.5 $\sim$ 2.3, could know that Damping layer has excellent attenuation performance in side of vibration reduction. Measurements of vibration using accelerometers by adhesion of Damping layer, square Plate by Separation of Damping layer is less binding of Damping layer, analyzed low loss factor and Natural Frequency by free Vibration of Square Plate.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2005년도 추계학술대회논문집
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• pp.381-384
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• 2005

The purpose of this study is to develop a prediction model for evaluating heavy-weight floor impact sounds in a test building. Three rooms in the test building (slab thickness In and 240mm), which consist of frame concrete structures were tested and modeled. First, the SPL distribution in the receiving room was analyzed by measuring SPL at 90 positions using a bang machine. Then, a vibration model using finite element method is proposed considering the material properties and boundary conditions. In addition, the result of transient analysis was compared with field measurements using a standard heavy-weight impact source. Through a vibro-acoustic simulation program, an acoustic model evaluating the building elements (reflected wall, nor, window and door) was proposed. Finally, validation of the prediction model was conducted by vibro-acoustic analysis with field measurements of noise radiation characteristics in receiving rooms.