This study was undertaken to investigate the distribution characteristics of the hazardous agents in indoor environment in 7 vessels in Incheon harbor from July to August, 2004. The measured parameters include several indoor air pollutants (PM10, CO2, HCHO, and TVOCs) and physical parameters (noise, vibration, temperature, and humidity). The levels of pollutants and hazardous components in vessels were compared with standards and guidelines of indoor air quality on the Ministry of Environment and the Ministry of Labor in Korea. The major results obtained from this study were as followed : The PM10 and CO2 levels in every vessel did not exceed the indoor air standard of 150 ㎍/㎥ and 1000 ppm, respectively. The level of PM10 showed a decreasing tendency as the weight of vessels is increased. The airbornce concentration of HCHO was the highest one by exceeding its standard in a 500 ton vessel. The noise level in engine room exceeded the workplace standard (90 dB(A)) recording above 100 dB(A). The TVOCs level in every engine room was more than its standard (500㎍/㎥). Based on our preliminary study of indoor air pollutants in vessels, it is suggested that long and middle term plan for the management of IAQ should be established through future investigation of vessels.
An analytical method for trimethylamine in ambient air was developed, using headspace gas chromatography with flame ionization detection. Trimethylamine was collected on the acid filter which was impregnated sulfuric aicd in the 47 ㎜ diameter of glass fiber filter. Trimethylamine collected on the acid filter was regenerated in the headspace vial and introduced into the GC analytical column directly. Several parameters such as sample volume, equilibrium temperature and time, and slurry method of filter were optimized to provide maximum detection response. Resolution power also compared according to liquid phase of analytical column. The detection limit of method was 0.13 ppb with 50 L sampling volume. The developed acid filter method is easy to deal with the field sampling and the method was adopted as the standard method for odor analysis in Korea.
The present study aims to develop a web-based model for English teacher evaluation, which purports to encourage a teacher to get actively involved in his or her own professional development through critical reflection upon teaching. The evaluation model using portfolio is based on the assumption that the teacher should play a key role in the evaluation process in order to bring about change in teaching. Another theoretical premise of the model is that data on teaching should be gathered from multiple sources such as observation, student performance and self-appraisal. The web-based model encourages stakeholders, e.g., administrators, headteachers, parents, to take part in the evaluation process. The model reflects the findings of a questionnaire survey on teachers’ perceptions on teacher evaluation and their needs. It is suggested that a number of factors related to administration, technology and content should be considered for the effective application of the model. Some suggestions are also made concerning evaluator training, time constraints, institutional support, and further research.
군위군 오이재배지역을 정밀토양도를 이용하여 토양특성을 조사하고, 군위군 노지 및 시설오이 재배지 토양의 물리화학적 특성을 조사하여, 연작과 관행적인 토양관리로 인하여 저하된 토양의 이화학적 특성을 오이재배에 적합한 토양으로 개량하기 위한 기초자료로 이용하고자 토양조사를 실시하였다. 조사지역은 군위군 군위읍 외랑리 오이재배단지로서 주요 토양통은 토양도에 나타난 단북통과 신정통이 가장 넓게 분포하였으며, 점토함량은 시설재배지내 토양의 경우 양토이었으며, 시설재배지의 외부 토양의 경우 23.8%로 높게 나타났다. 오이재배지 토양의 화학적 특성 결과에 대한 오이재배지 토양의 적정범위와 비교하여 보면 일반적인 화학적 성질에서 서는 유효 인산의 함량이 적정범위보다 높은 것을 알 수 있으며, 치환성 양이온 함량은 시설재배지의 외부토양은 적정범위에 속하나 시설재배지 내부토양은 모두 높은 것으로 나타났으며, 최상부 토양은 매우 높으나 10cm 이하는 깊이에 따라 뚜렷한 차이는 없었다. 오이 재배지 토양 중 중금속 함량은 모두 기준치보다 높게 나타났는데, 구리의 함량이 시설재배지가 노지재배지보다 높게 나타났다. 시설재배지의 경우는 다른 곳과 달리 표토 위에 부숙이 어려운 유기물의 과량투입에 따라 표토 위의 유기물 30% 이상의 유기물 층이 존재하여 모든 양분 성분이 매우 높게 나타났다. 따라서, 안정적인 생산을 위해서는 토양분석에 따른 토양관리법의 확립이 필요할 것으로 판단된다.
In mold structure machining, tool interference is a phenomenon which results from a collision between a blade of tool and a workpiece. Also tool collision is a phenomenon which results from a collision of holder with the object to be machined. These phenomena not only cause damages to mold and tool but also increase machining time and cost. To detect a collision of a tool to mold structure, first of all, the mold structure and a tool must be defined with famous geometric models such CSG, B-rep, and Voxel. A tool is defined as a combination of the blade, the shank, and the holder. This thesis reviews various collision detection algorithms using z-map and computer 3D graphic collision detection algorithms for the tool in machining a mold structure.
Bacillus thuringiensis strains were isolated from the domestic soil and a strain was selected that had a new host range and high toxicity against agriculture insect pest. The 142 samples of soil were sampled from the mountains, paddy fields and patches, in Daejon, Chungnam, Chungbuk and Jeonbuk and used for the investigation. Sixteen B. t strains were isolated from 12 samples among collected samples. There were 11 strains that showed toxical activity on Plutella xylostella (Lepidoptera: Yponomeutidae), 7 strains on Spodoptera litura (Lepidoptera: Noctuidae), 5 strains on Arcte coerulea (Lepidoptera: Noctuidae), 5 strains on Culex pipiens pallens (Diptera: Culicidae) among the 16 isolated B. t strains. But there were not any strains that showed activity against Hyphanria cunea (Lepidoptera: Arctiidae) and Sitophilus oryzae (Coleoptera: Rhynchophoridae). And also some of B. thuringiensis strains showed insecticidal activity with 2, 3 or 4 kinds of insects. But there were also 3 strains that did not show any activities to the 6 insects which were used in the experiment. When examined with a phase-contrast microscope, the insecticidal crystal protein produced from 16 selected strains had 13 bipyramidal and 3 spherical shapes. The insecticidal bioactivity of the S. litura showed 100% mortality when there were 1.3×10⁷ (cfu/㎖) of CAB109 isolates.