In the blast work inevitably exists a vacant space between drilling hole wall and explosive. So it cause an blast inefficiency called on a decoupling effect. In this study, For enhancing the detonation efficiency and reducing the environmental problem(vibration, noise, etc.), water is used to fill the vacant space. Water filling has many advantages such as efficiency, low price and workability. In the comparison analysis the field test is carried out. It result on an aspect of the effectiveness and safety. The result measured in the field is as follows; First, the water tube blast reduces the vibration by 16.5% and lessen the noise by 1% comparing to general blast. Secondly, water tube blast makes a separation distance shortened by maximum 15m. Thirdly, in the case that the same quantities of explosive are used, the amount of crushing per hole increased by about 12.8% in water blast method. The quantity of the explosive is reduced by about 11.4% comparing with general blast.

Ensemble classification involves combining individually trained classifiers to yield more accurate prediction, compared with individual models. Ensemble techniques are very useful for improving the generalization ability of classifiers. The random subspace ensemble technique is a simple but effective method for constructing ensemble classifiers; it involves randomly drawing some of the features from each classifier in the ensemble. The instance selection technique involves selecting critical instances while deleting and removing irrelevant and noisy instances from the original dataset. The instance selection and random subspace methods are both well known in the field of data mining and have proven to be very effective in many applications. However, few studies have focused on integrating the instance selection and random subspace methods. Therefore, this study proposed a new hybrid ensemble model that integrates instance selection and random subspace techniques using genetic algorithms (GAs) to improve the performance of a random subspace ensemble model. GAs are used to select optimal (or near optimal) instances, which are used as input data for the random subspace ensemble model. The proposed model was applied to both Kaggle credit data and corporate credit data, and the results were compared with those of other models to investigate performance in terms of classification accuracy, levels of diversity, and average classification rates of base classifiers in the ensemble. The experimental results demonstrated that the proposed model outperformed other models including the single model, the instance selection model, and the original random subspace ensemble model.

Currently many geriatric hospitals have been built in Korea because increasing aging rapidly. However the increasing geriatric hospitals make the increasing safety accidents. Therefore this study is conducted by survey and face-to-face talk with the fire safety managers for analyzing safety problem of geriatric hospitals which number is twelve among 15 geriatric hospitals in the north of Chung-buk area. The result of this study is that geriatric hospitals are very old. Fire safety managers holding the fire safety license are a level 2 issued by the Korea Fire Safety Association(KFSA). And the fire safety inspection ability of them is normal (58%). Furthermore a fire safety budget ratio is 83% (A little) in the company yearly budget. And ratio having the fire inspection equipment in the building is 42% (A little) and 33% (Nothing). Satisfaction ratio of their duty is 66% and they also get stress from heavy duty and heavy responsibility. In conclusion, CEO needs to invest and interest the improvement of job performance, satisfaction ratio and fire safety facility. Also government needs the improvement of system to support and supervise the fire safety of geriatric hospitals consistently.

Many organizations have transformed their business in order to survive and compete in the future. They generate projects by creating a vision, using strategies and objectives with funds aligning strategies and make efforts to complete them successfully because project success leads to business success. All projects have triple constraints such as scope, time, and cost to be completed. Project cost performance is a key factor to achieve project goals and which is mostly related with risks among various cost drivers. Projects require a cost estimation method to complete them within their budget and on time. An accurate budget cannot be estimated due to the uncertainties and risks. Thus some additional money should be funded in addition to the base budget as a contingency reserve for identified risks and a management reserve for unidentified risks. While research on contingency reserve for identified risks included in project budget baseline have been presented, research on management reserve for unidentified risks included in total project budget is still scarce. The lack of research on estimation method and role of the management reserve have made project managers little confidence to estimate project budget accurately with reasonable basis. This study proposes a practical model to estimate budgets including contingency and management reserves for not only project cost management but also to keep the balance of organization’s total funds to maximize return on investments for project portfolio management. The advantages of the proposed model are demonstrated by its application to construction projects in Korea and the processes to apply this model for verification are also provided.

This study was conducted by survey and inspection of stair passage leading lights in shopping buildings which are more than 5 stories and have an underground parking lot located at Pyeongtaek-si and Seongnam-si. Number of shopping building for this study is 30 and of stair passage leading light inspected by two lights in each shopping building is 60. The result of this study is that the type of installed leading lights is LED(77%), and 60% of leading lights has problem such as no cleaning, scratch and discoloration, etc. The height of installed leading lights meets the fire law which is less than 1m from the floor. Visible condition of leading lights is good except some leading lights which have a little visible problem due to banner advertisement. 37% of standby power has flickered and went out. 93% of total leading lights meets the fire law which is more than 1lux from 0.5m distance, but cold cathode fluorescent lamps(CCFLs) have the problem which not meets proper brightness level based on fire law. In additional measurement result, zero lux of leading lights is 32%(from 1m distance), 68%(from 1.5m distance) and 98%(from 2m distance). Leading light is very important facility because it is eyes and guide when emergency. Therefore, proper fire facility operating function inspection and total detailed inspection are important to keep the good condition of leading light except simple visual check, and also improvement in law system of type approval, fire construction inspection and illumination level will be needed.

복합재는 높은 비강도와 비강성을 가지고 있어 자동차, 항공기 등 전반적인 산업분야에서 널리 사용되는 재료이다. 우주선의 노즐 부분과 같이 높은 온도뿐만 아니라 높은 압력이 작용하는 환경에서 사용하기 위한 재료로 복합재가 필요하다. 복합재의 물성치를 아는 것은 매우 중요한데 모재(matrix)와 강화섬유(fiber) 각각의 물성치를 수치적으로 대입해 얻는 결과는 실험값과의 오차가 커 예측하는데 있어 더 정확한 방법이 필요할 것이다. 본 연구에서는 유한요소법을 이용한 EDISON용 CASAD solver 프로그램을 활용해 분석하였다. matrix와 fiber의 물성치를 대입해 복합재의 물성치를 구해 실험으로 측정된 물성치, 경험식으로 계산된 물성치와 비교를 하였다.

This study is the sequel of a companion paper (I. Algorithm) for assessment of the seismic performance evaluation of structure using ground motions selected by the proposed algorithm. To evaluate the effect of the correlation structures of selected ground motions on the seismic responses of a structure, three sets of ground motions are selected with and without consideration of the correlation structure. Nonlinear response history analyses of a 20-story reinforced concrete frame are conducted using the three sets of ground motions. This study shows that the seismic responses of the frames vary according to ground motion selection and correlation structures.

It is important to select an accurate set of ground motions when conducting linear and nonlinear response history analyses of structures. This study proposes a method for selecting ground motions from a ground motion library with response spectra that match the target response spectrum mean, variance and correlation structures. This study also has addressed the determination of an appropriate value for the weight factor of a correlation structure. The proposed method is conceptually simple and straightforward, and does not involve a simulation algorithm. In this method, a desired number of ground motions are sequentially selected from first to last. The proposed method can be also used for selecting ground motions with response spectra that match the conditional spectrum. The accuracy and efficiency of the proposed procedure are verified with numerical examples.

미국 AASHTO LRFD(AASHTO, 2012)나 국내의 도로교설계기준(2012)의 차랑충돌에 대한 교각설계기준을 참조하면 교각 설계 시 차량충돌에 대해 정적인 하중을 고려하도록 제시하고 있다. 한편 2003년 미국 네브래스카 주에 트럭이 교각에 충돌하여 교각 및 교량 상부구조가 붕괴되는 사고가 발생하는 등 차량충돌에 의한 교량붕괴사고는 홍수에 의한 교량붕괴사고에 이은 두 번째 요인으로 분류되기도 한다. 화물차량의 대형화와 도로시스템의 개선으로 인하여 이러한 사고가 발생할 가능성이 중가하고 있다고 볼 수 있다. 본 연구에서는 교각 설계시 차량충돌에 대한 동적 해석을 수행하게 되면 많은 비용과 시간이 소요되어 실용적인 측면에서 연구결과가 쉽게 반영되지 못하고 있으므로 충돌해석 비용과 시간을 저감할 수 있는 모델축소법(model reduction)을 이용한 해석방법을 개발하였으며 그 효용성을 최종변위에 대해 직접충돌해석결과와 비교함으로써 평가하였다.

Self-assembled monolayers(SAM) of microspheres such as silica and polystyrene(PS) beads have found widespread application in photonic crystals, sensors, and lithographic masks or templates. From a practical viewpoint, setting up a highthroughput process to form a SAM over large areas in a controllable manner is a key challenging issue. Various methods have been suggested including drop casting, spin coating, Langmuir Blodgett, and convective self-assembly(CSA) techniques. Among these, the CSA method has recently attracted attention due to its potential scalability to an automated high-throughput process. By controlling various parameters, this process can be precisely tuned to achieve well-ordered arrays of microspheres. In this study, using a restricted meniscus CSA method, we systematically investigate the effect of the processing parameters on the formation of large area self-assembled monolayers of PS beads. A way to provide hydrophilicity, a prerequisite for a CSA, to the surface of a hydrophobic photoresist layer, is presented in order to apply the SAM of the PS beads as a mask for photonic nanojet lithography.

폴리설폰막 위에 친수성 고분자를 Layer-by-Layer법으로 코팅하여 복합막을 제조하였다. FE-SEM 분석을 통하여 복합막 표면과 기공 내 코팅층을 확인하였다. 또한 100 ppm NaCl 용액에 대한 복합막의 투과성능 평가를 실시하였다. 복합 막 제조를 위한 코팅 고분자는 PVSA, PEI, PAA, PSSA, PSSA_MA를 사용하였다. 폴리설폰막 표면에 8,000 ppm PAA (이 온세기 0.35) 수용액을 3분 동안 코팅한 뒤 10,000 ppm PEI 수용액을 4분 동안 코팅하였다. 그 결과 PAA-PEI 복합막의 투과 도는 101 LMH, 제거율은 66.7%로 가장 좋은 투과성능을 나타내었다. PAA-PEI 복합막의 투과성능은 도레이케미칼의 NE 4040-70 (투과도 = 30 LMH, 염 배제율 = 40~70%) 제품과 유사한 성능을 보여주는 우수한 투과 특성을 나타내었다.

A fire sprinkler system is very important to extinguish fire in the building. The sprinkler system initiates sprinkler discharge if the detection system identifies a developing fire and opens the pre-action valve. However, pre-action fire sprinkler systems mainly installed in the underground parking lot at the apartment complex do not properly operate at fire if the connection type of fire sprinkler systems does not properly installed and operated. This study identified the relationship between fire dispersion & damage and the connection type of water supply in the sprinkler system from many fire cases at the apartment complex in South Korea. In addition, this study also identified the water supply differences and characteristics between South Korea and foreign countries. The main purpose of this study is also to improve the water connection types in the sprinkler system that can reduce the potential failures of pre-action valve operation through electrical signal system. The study also suggests the improvement plan for water connection types in pre-action fire sprinkler system that can minimize potential failure of pre-action fire sprinkler system. The suggestions for revising the fire safe standard in South Korea includes letting the water supply pipe of sprinkler system water inlet connect to the second side of pre-action valve and the water flow device that can minimize potential failure of sprinkler system.

The goals of automatic fire detection equipment in Japan and South Korea are the detection in early fire stage, alarm and finding the location of the fire. Japan also has similar operation system and signal transmission method compared with South Korea. The standards of fire detection equipment in Japan are established their own standards. The automatic fire detection equipment in Korea has been developed with benchmarking the Japanese system in early 1950’s and follows the decree on the basis of Japan’s fire services. NFPA 72, which is automatic fire detection equipment in U.S.A. and verified through the experiment and test, expects to reflect to our automatic fire detection equipment after modification and supplement.

The alternative advanced lead-acid battery is one of the promising ultrabattery. The lead-carbon battery is also reusable battery consisted of positive electrodes, negative electrode and Electrolyte. Currently, numerous research efforts are performing on activated carbon used as the novel cathode materials. In this study, we have used graphite sheet coated P60 carbon as a cathode material. Graphite electrode is different form used in the normal lead-carbon batteries. It will be expected to increase the conductivity and weigh light. Through charge-discharge experiment and EIS, battery performance analysis were compared with grid form negative electrode. After that, SEM, RAMAN and XRD analyses were studied.

고분자 전해질 막의 성능을 개선하고자 사용된 대표적인 무기물인 solid acid가 첨가된 복합막의 경우 고온에서 높은 열안정성을 나타내며 친수성이 강해지는 장점을 나타내지만 물에 녹는 단점을 가지고 있다. 그러므로 본 연구에서는 phosphotungstic acid(PWA)의 이온전도성을 증가시키며 물에 용해되는 성질을 제거하기 위하여 실리카 입자를 sol-gel법을 이용하여 술폰산기와 아민그룹을 도입시킨 입자를 제조한 후 sulfonated poly(arylene ether sulfone)(SPAES) 고분자에 첨가하여 복합막을 제조하였으며 특성평가가 이루어졌다.

극성 기체인 CO2를 분리하기 위해 UiO-66과 PVC-g_POEM을 사용하여 Membrane을 만들었다. UiO-66(MOFs)는 높은 수분 안정성뿐 아니라, 강산 및 강염기 수용액 하에서도 안정된 구조를 유지한다. 또한 다양한 용매에 사용할 수 있는 장점을 가지고 있다. 본 연구에서는 PVC-g-POEM 고분자 매트릭스에 높은 비표면적을 갖는 UiO-66 입자를 분산하여 Mixed Matrix Membrane을 제조하였다. 분리막 두께에 변화시키며, 다양한 이성분계 혼합기체에 대한 투과 실험을 실시하였다. 합성된 MMM의 결정상은 XRD로, 두께 및 표면 등은 SEM을 통해 분석하였으며, 기체 투과 실험에서 투과된 기체의 조성은 GC를 이용하여 분석하였다.

The H2/CO2selectivity across ZIF-7 membrane prepared by in-situ growth method at 105°C synthesis temperature for 2 h, was the highest at 15.98, nearly 4 times higher than H2/CO2 Knudsens E.q. factor of 4.7. ZIF-7 membranes prepared from in-situ growth method also surprisingly performed better than ZIF-7 membranes prepared by other innovative techniques such as electro-spray deposition and secondary growth methods. (selectivity : 9.59 and 4.7, respectively) Despite lower selectivity performance than the numerically predicted results, the micro-porous ZIF-7 membrane prepared in this work demonstrated higher H2 permeability of 3770 barrer. Performance comparison between various inorganic membranes, including ZIF-7 & ZIF-8 membranes, was made and a new upper boundary for inorganic membranes was also constructed and reported.

기존의 전기 탈이온 공정(EDI)은 전기투석법과 이온교환수지법을 혼합한 공정으로 알려져있다. 여기서의 모듈은 전기투석을 위한 양이온교환막과 음이온교환막이 있고 이 막 사이에 이온교환수지를 채워 넣는 형태로 제조된다. 이것을 기초로 요즘 전기 흡착 탈이온(EAD) 공정은 바이폴라막과 이온교환수지를 이용해서 모듈을 제조하고 있다. 그래서 모듈에 이용되는 양이온교환막으로 술폰화시킨 SEBS triblock copolymer를 이용했다. 게다가 술폰화시킨 SEBS, 물분자, 히드로늄 이온을 모델링하고 술폰화시킨 SEBS, 히드로늄 이온과 물분자의 의 동역학을 분자동역학시뮬레이션을 이용해서 살펴보았다. 그리고 실제 실험을 통한 비교분석을 진행했다.

지하수를 식수원으로 활용하고 있는 대부분의 소규모 마을상수도 시설에서 방사성물질 발현에 대한 문제가 지속적으로 재기됨에 따라, 2015년 수질감시기준에 우라늄 항목이 추가되었다. 효과적인 우라늄 처리를 위하여, 마을상수도 시설에 NF 및 RO를 이용한 처리공정의 적용이 증가하고 있으나, 적용된 분리막의 효율적인 관리방법이 미흡한 현실이다. 전문적인 운영관리인원이 부족한 현실에서 안정적인 RO공정의 운영을 위한 방안으로 분리막의 세척방안 마련이 필요하다. 이를 위하여 본 연구에서는 RO공정을 마을상수도에 도입시키고 운영하며, 발생되는 RO 분리막 오염의 효과적인 제어방법을 도출코자 하였다. 효율적인 세척방법으로 산/염기의 순차적 세척방법이 도출되었으며, 약 93%의 분리막 세척효과를 확인하였다.

다공성 지지체인 Polyvinylidene flouride(PVDF) 중공사막에 가압법을 이용하여 수용성 고분자인 Poly(styrene sulfonic acid) (PSSA)와 Polyethyleneimine (PEI)으로 강제 파울링 유도시켜 나노여과막을 제조하였다. 가압법과 담금법의 차이 및 코팅용액의 농도, 코팅시간, 가교제의 영향에 대하여 알아보기 위하여 NaCl 100 ppm 에서 투과도와 제거율을 측정하였다. 측정결과 PSSA 2%에 이온세기 0.3으로 2분 코팅한 다음 PEI 3wt%에 이온세기 0.1으로 1분 코팅한 경우가 투과도 118 LMH, 제거율 79.1%로 가장 좋은 결과를 나타내었다.