A novel route to prepare Nd-Fe-B magnetic particles by utilizing both spray drying and reduction/diffu- sion processes was investigated in this study. Precursors were prepared by spray drying method using the aqueous solu- tions containing Nd salt, Fe salt and boric acid with stoichiometric ratios. Precursor particles could be obtained with various sizes from 2 to 10 µm by controlling concentrations of the solutions and the average size of 2 µm of precursors were selected for further steps. After heat treatment of precursors in air, Nd and Fe oxides were formed through desalt- ing procedure, followed by reduction processes in Hydrogen (H2) atmosphere and with Calcium (Ca) granules in Argon (Ar) successively. Moreover, diffusion between Nd and Fe occurred during Ca reduction and Nd2Fe14B particles were formed. With Ca amount added to particles after H2 reduction, intrinsic coercivity was changed from 1 to 10 kOe. In order to remove and leach CaO and residual Ca, de-ionized water and dilute acid were used. Acidic solutions were more effective to eliminate impurities, but Fe and Nd were dissolved out from the particles. Finally, Nd2Fe14B magnetic particles were synthesized after washing in de-ionized water with a mean size of 2 µm and their maximum energy prod- uct showed 9.23 MGOe.

Real Time PCR을 이용한 벼 흰잎마름병균의 밀도를 측정할 수 있는 새로운 방법을 개발하였다. Real Time PCR을 이용하여 벼 흰잎마름병을 예찰하기 위하여 TaqMan MGB probe를 이용한 프라이머인 Xan_PahgeF & Xan_PahgeR primer와 Xan_Pahge FAM MGB probe를 제작하였으며, 높은 특이성이 인정되었다. 병원균 배양액, 벼 흰잎마름병원균의 DNA, 병원세균에 오염된 물에서도 효과적으로 검출이 되었다. 농수로물이나 관개수에서 벼 흰잎마름병균의 밀도를 측정할 때 정량 PCR의 저해인자 제거 후 신속하게 벼 흰잎마름병균의 밀도를 측정할 수 있다.

목적: 본 연구에서는 안경체인점에 근무하고 있는 안경사들을 대상으로 이들의 감성지능과 고객지향성, 고객만족과의 관계를 살펴보고자 하였다. 방법: 이를 위하여 감성지능과 고객지향성, 고객만족에 대한 선행연구들을 기반으로 연구모형을 설정하고 가설을 도출하였다. 이를 위하여 A안경체인점에 근무하고 있는 안경사 248명을 대상으로 설문조사를 실시하였으며 총 240부의 유효한 설문지를 이용하여 실증분석을 실시하였다. 결과: 첫째, 안경사들의 감성지능을 구체적으로 4가지 요인으로 세분화하고 고객지향성과의 관계성을 검증한 결과, 자기감성이해, 감성조절, 감성활용이 고객지향성에 정(+)의 영향을 미치는 것으로 나타났다. 둘째, 안경사들의 고객지향성은 고객만족에 유의한 정(+)의 영향을 미치는 것으로 나타났다. 셋째, 감성지능과 고객만족간의 영향관계에 있어 고객지향성의 매개역할을 검증한 결과, 자기감성 이해만이 고객만족 간의 관계에서 부분매개역할을 하는 것으로 확인되었다. 결론: 연구결과에 따르면, 안경체인점 점주들은 안경사들의 인지능력뿐만 아니라 감성능력을 보다 개발하고 관리해줌으로써 더 높은 성과를 낼 수 있음을 인지하게 될 것이다.

There are a number of construction methods to build spatial structures such as erection method, Element method, Block method, Sliding method, Lift-up method and Push-up method. These methods are uneconomical and low accuracy, and require long construction duration because of a need of a scaffold or a tower crane to build spatial roof frame. In this study, the construction method to erect a truss structure was proposed as an economical and easy installation method. The proposed method has end hinges of keel truss and winches with horizontal cable. This method makes safe and accurate production and reduces construction duration because trusses are built on the floor or supporter. The goal of this study is to verify the validity of construction method by building scale model using the proposed method.

PURPOSES : Compared to the criteria from advanced countries, Korea has conservative criteria for the buried depth of pipeline (about 30~70cm deeper) causing the waste of cost and time. Therefore, this research investigated the effect of various buried depths of pipeline on pavement performance in order to modify the criteria to be safe but economical. In addition, a recycled aggregate which is effective in economical and environmental aspect was evaluated to be used as a refilling material. METHODS : In this study, total 10 pilot sections which are composed with various combinations of pavement structure, buried depth of pipeline, and refilling material were constructed and the telecom cable was utilized as a buried pipeline. During construction, LFWD (Light Falling Weight Deflectometer) tests were conducted on each layer to measure the structural capacity of underlying layers. After the construction is completed, FWD (Falling Weight Deflectometer) tests and moving load tests were performed on top of the asphalt pavement surface. RESULTS : It was found from the LFWD and FWD test results that as the buried depth decrease, the deflections in subbase and surface layer were increased by 30% and 5~10%, respectively, but the deflection in base layer remained the same. In the moving load test, the longitudinal maximum strain was increased by 30% for 120mm of buried depth case and 5% for 100mm of buried depth case. Regarding the effect of refilling material, it was observed that the deflections in subbase and surface layer were 10% lager in recycled aggregate compared to the sand material. CONCLUSIONS : Based on the testing results, it was found that the change in buried depth and refiliing material would not significantly affect the pavement performance. However, it is noted that the final conclusion should be made based on an intensive structural analysis for the pavement under realistic conditions (i.e., repeated loading and environmental loading) along with the field test results.

PURPOSES : This study presents the noise level and frequency characteristics investigated in the national highways with the consideration of various measuring conditions and/or methods. METHODS : The noise levels on the asphalt concrete pavement(ACP) and the jointed plain concrete pavement(JPCP) of the national highway were measured and analysed with respect to three variables, i.e., pavement type, surface condition, and measurement distance. The PASS-By method is utilized for the noise measurement and then using CPB spectrum analysis method with 1/3 octave bandwidth, the noise levels and frequency characteristics were calculated for two-second periods before and after the peak noise. RESULTS : Depending on the pavement type, the noise level was changed as the average noise levels are 73.3dB(A) and 78.3dB(A) for ACP and JPCP, respectively. With respect to the effect of surface condition, the average noise levels for crack H(high), M(medium), and L (low) sections are 77.4dB(A), 77.4dB(A), and 78.1dB(A), respectively. Regarding the measurement distance, 1.2meter difference in measuring location reduces 1.6dB(A) of noise level; the average noise levels at 5.3m and 7.5m from the centerline of outer lane are 72.8dB(A) and 71.2dB(A), respectively. It should be noted that the noise levels are slightly different as a function of vehicle speed and type. However, the overall trends for each case was similar. It was found that the domain frequency bands for ACP and JPCP were 400Hz~2000Hz and 500Hz~2000Hz, respectively. CONCLUSIONS : Based on the analysis with the measured noise date from national highway, it was concluded that the noise level and frequency band vary depending on the various conditions. It was also found that some variables significantly affect the noise level while others do not. With further systematic investigation, the comprehensive noise characteristics on the national highway can be achieved. Using such database, it is possible to develop the fundamental noise reduction technology.

PURPOSES : The PMS(Pavement Management System) has been utilized in order to efficiently allocate the limited budget for the maintenance of national highway system. In the PMS of national highway, surface pavement condition is evaluated by using the VI (Visual Index). However, the VI is determined only by considering the cracking rate (%) and rut depth (mm), which is not reflecting the IRI (International Roughness Index) that is known as an important factor of pavement performance. In this study, the NHPCI (National Highway Pavement Condition Index) which includes the cracking rate (%), rut depth (mm), and IRI (m/km) is suggested for determining the rehabilitation methods group. METHODS : First, the rehabilitation methods performed between 2008 and 2010 on the national highway is classified and then, NHPCI is determined for each rehabilitation method. Next, the NHPCI for each rehabilitation method is grouped through the interval estimation of the population mean and T-test analysis. RESULTS : According to NHPCI range, the rehabilitation methods are divided into four categories: Not Required, Preventive Maintenance, Overlay Treatment (with or without cutting), and Full-scale Treatment (i.e., reconstruction). CONCLUSIONS : Based on this study, it is recommended that the appropriate NHPCI range should be determined through the combination of the rehabilitation categories and Decision Procedure of Pavement Distress Condition Visual Index.

In the present study, we systematically investigated the effect of Mn addition on nitrogenation behavior and magnetic properties of Sm-Fe powders produced by reduction-diffusion process. Alloy powders with only single phase were successfully produced by the reduction-diffusion process. The coercivity of powder rapidly increased during nitrogenation and reached the maximum of 637 Oe after 16 hours. After further nitrogenation, it decreased. In contrast, the coercivity of powder gradually increased during nitrogenation for 24 hours. The coercivity of powder was higher than that of powder at the same condition of nitrogenation. It was considered that the Mn addition facilitates the nitrogenation of powder and enhances the coercivity.

돈분뇨 액비 시용 후 경운처리에 의한 청보리, 호밀, 트리티케일, IRG의 생육과 잡초발생량 차이를 구명하였다. 파종기에 한발이 지속된 포장의 수분함량을 조사한 결과 화학비료 처리구와 무처리구에서는 8.5 ~ 9.1%를 나타냈으나, 액비를 살포한 포장은 20.5 ~ 23.1% 수준이었다. 파종 15일 후에 유묘출현율은 액비 처리구에서는 화학비료 및 무처리구에 비하여 청보리는 2.9배, 호밀과 트리티케일은 각각 2.2배, 2.4배 높게 나타났다. 또한 시험작물 모두 초장이 액비시용구에서 약 2배 이상 증가하였다. 월동 후 최고분얼기에는 모든 작물의 초장이 화학비료 및 무처리구에 비하여 액비처리구가 1.1 ~ 1.3배 길었고 경수도 비슷한 경향을 보였으며, 분얼수는 청보리, 호밀 및 트리티케일이 각각 4.5개, 5개 및 6개/개체로 화학처리구에 비해서 1개체씩의 증가를 보여 한발에 의한 초기 생육차이가 월동 후에도 지속되는 것으로 확인되었다. 한편 잡초발생은 답리작포장이기 때문에 뚝새풀이 주로 발견되었으며, 액비 처리구는 경운으로 m2당 잡초발생수가 5개 수준이었으나, 화학비료 처리구는 무경운으로 145개 발생되어 29배의 잡초발생 차이를 보였다. 월동 후 액비시용하고 경운을 하면 비료효과가 지속되어 화학비료 처리구보다 우수한 생육을 보였으나, 액비시용 후 무경운 처리는 낮은 생육을 보였다. 수확기 생체중 역시 액비처리후 경운처리구가 가장 높았으며, 청보리, 호밀, 트리티케일, IRG 모두 증수되었다. 따라서 한발이 지속될 경우 액비살포 후 경운은 작물의 영양원으로 뿐만 아니라, 수분공급의 효과로 종자의 발아를 촉진시켜 초기생장 및 수량증수에 크게 기여하며 부수적으로 잡초발생도 감소시키는 것으로 판단된다.

게임에 대한 인식이 점차 그 유용성을 인정하는 쪽으로 변화 하면서 교육용 게임의 시장이 크게 성장하고 있다. 하지만 아직까지도 교육용 게임은 다른 장르의 게임에 비해 많이 활성화 되지 못하고 있는 것이 현실이다. 따라서 본 연구에서는 교육용 게임의 몰입에 영향을 미치는 요인들을 분석해보고 궁극적으로 게임 개발을 위해 어떠한 요인들이 초점을 맞추어야 할 것인가에 대한 방향을 제시 하고자 하며 향후 교육용 게임에 관한 연구 및 교육용 게임 산업에 도움이 되고자 한다. 본 연구의 결과 다음과 같은 결론을 확인하였다. 첫째, 교육용게임의 몰입에 있어 교육적 효과, 시나리오, 보상은 긍정적인 영향을 미친다. 특히 감정적 몰입에는 교육적 효과와 보상이, 계산적 몰입에는 교육적 효과와 시나리오가 긍정적인 영향을 미친다. 둘째, 그래픽, 조작성은 교육용 게임의 몰입에 미치는 영향력을 확인하지 못하였다. 셋째, 교육용 게임에서 난이도가 너무 어려우면 감정적 몰입을 하는데 어려움을 준다.

When gasoline car using gasoline additives and lubricant additives was running, we were able to find the characteristics which is related to noise and vibration, and also affection of emission by chassis dynamometer. The results are followed. 1) change of HC was not related to lubricant additives, it turned out that change of HC will be low, when ratio of gasoline additives is high. 2) NOx was detected to high, when ratio of lubricant additives is high. And when ratio of gasoline additives was 8.29, the data for NOx was lowest. 3) CO2 was 13.5～14% constantly, this result is not related to ratio of lubricant additives and gasoline additives. 4) Noise was not related to both of them ratio of lubricant additives and gasoline additives. But vibration was downed to 120Hz at 40km/h due to lubricant additives.

PURPOSES : Recently, the mechanistic-empirical overlay pavement design program that is linked with Korea Pavement Research Program (KPRP) has been developed. This paper focused on establishing the framework and developing the program for the asphalt overlay design over the existing asphalt concrete pavement. METHODS : The overlay pavement design program developed in this study was investigated to assess the sensitivity to various pavement conditions, such as the damage level and thickness of existing layers. In addition, the actual overlay design on currently performing pavement was carried out as a practical example. RESULTS : From the sensitivity analysis, it was found that the thickness and damage level of existing asphalt layer mostly affect the overlay design results. In addition, under the same condition, the overlay pavement would better perform in cold region. From the overlay design with the actual condition, it is noted that the overlay thickness varies depending on the given condition. CONCLUSIONS : Based on various evaluations, it was concluded that the overlay design program developed in this study is a reliable and reasonable tool to be used in the actual pavement design.