• Korean Journal of Organic Agriculture
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• v.19 no.2
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• pp.199-214
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• 2011

This study was conducted to investigate the effect of organic dietary metabolizable energy (ME) and crude protein (CP) on productivity, meat quality and blood composition of crossbred chicks (hanhyub 3 ho) for different growring periods. Experiments were factorially designed with ME 3,000, 3,100kcal/kg and CP 21, 22, 23% for starter (0-4wks); ME 3,100, 3,150, 3,200kcal/kg and CP 18, 19, 20% for grower (5-8wks); ME 3,100, 3,150, 3,200kcal/kg and CP 15, 16, 17% for finisher (9-10wks). The total number of chicks and replicate of each treatment for starter, grower, finisher were 720, 4; 702, 6; 468, 4, respectively. The diets was mixed with more 90% organic feed ingredients. The productivity were not influence by dietary ME for starting period. Weight gain and feed intake were significantly increased in CP 23% treatment than CP 21, 22% treatment (P<0.05). FCR was improved as dietary CP increased (P<0.05). Weight gain was tended to be increased by decreaing ME content and increasing CP contents for growing period. Feed intake showed no difference among the ME and CP treatment groups. FCR improved significantly in CP 19, 20% compared with CP 18% (P<0.05). Weight gain was not significantly different between ME and CP treatments for finishing period. Feed intake was lower in ME 3,150, 3,200kcal/kg than the ME 3,100 kcal/kg treatment (P<0.05). FCR was higher in ME 3,100kcal/kg than ME 3,150, 3,200kcal/kg treatment (P<0.05). Interaction on productivity was not exited between ME and CP treatment groups for different feeding periods. There was no difference in the total protein, albumin, glucose and triglyceride amount in blood depending on dietary ME and CP contents. Total cholesterol was greatly decreased in ME 3,100kcal/kg than the ME 3,200kcal/kg (P<0.05), but not different between CP treatments. Cooking loss of breast meat was lower in ME 3,150kcal/kg than the ME 3,200kcal/kg (P<0.05). Moisture, shear force and pH were not statistically different among treatments. Protein solubility was increased by increasing ME and CP in diets. The collagen was tended to increase as dietary ME increased. Redness was remarkably higher in ME 3,150kcal/kg than the ME 3,100kcal/kg (P<0.05). Yellowness of meat fed ME 3,150kcal/kg showed significantly lower than other treatments (P<0.05). Therefore, the optium ME and CP to improve the productivity for each period were 3,000kcal/kg, 23%; 3,100kcal/kg, 19%; 3,150kcal/kg, CP 16%, repectively.

• Korean Journal of Poultry Science
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• v.34 no.1
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• pp.15-21
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• 2007

This study was conducted to evaluate the effects of dietary softwood by-products extract on growth performance, organ weight and intestinal microbes in organic broiler chicks. Five treatments were assigned to 200 broiler chicks with four replication, allocating 10 broiler chicks in each replication. Dietary treatments included control(Organic diet), +C(Organic diet + antibiotics), T1(Organic diet + softwood by-product powder 3.0%), T2(Organic diet + softwood by-product extract 0.05%) and T3(Organic diet + softwood by-product extract 0.1%). Body weight gain was higher in +C and T3 for overall period than control and T1. Feed efficiency of were slightly improved in +C and T3 groups compared with that of control and T1. The small intestine weight tended to be higher in control and +C, but it's length showed high in only T1 group. Gizzard weight was significantly higher in T2 compared with other treatments(P<0.05). In contrast, spleen weight was significantly lower in control group(P<0.05), whereas the weight of cecum and liver were not significantly different by dietary treatment. Intestinal microflora was significantly lower or/and seemed to be low in softwood by-products treatment groups than control. Digestibility of energy and protein were statistically lower in control and T1 than other treatments(P<0.05). The IgG concentration of birds fed antibiotics, softwood by-product extract was higher than control and T1, but was no significance. The results of this experiments indicated that softwood by-product extract would be possible to apply for the feed additive in organic broiler diets.

• International Journal of Highway Engineering
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• v.8 no.2 s.28
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• pp.63-74
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• 2006

During the construction of circular underground pipe, the non-proper compaction along the pipe and the decrease of compaction efficiency have been the main problems to induce the failure of underground pipe or facility. The use of CLSM (controlled low strength materials) should be one of the possible applications to overcome those problems. In this research, the full-scaled field test and the numeric analysis using PENTAGON-3D FEM program were carried out for three different cases on the change of backfill materials, including the common sand, the soil from construction site, and the CLSM. From the full-scaled test in field, the use of in-situ CLSM as backfill materials reduced the vertical and lateral deformation of the pipe, as well as the deformation of the ground surface. The main reason for reducing the deformation would be the characteristics of the CLSM, especially self-leveling and self-hardening properties. The measured earth pressure at the surround of the corrugated pipe using the CLSM backfills was the smaller than the other cases, and the absolute value was almost zero. Judging from the full-scaled field test and FEM analysis, the use of CLSM as backfill materials should be one of the best choices reducing the failure of the underground pipes.

• Korean Journal of Ecology and Environment
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• v.43 no.2
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• pp.263-270
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• 2010

This is a research on development of water purification equipment called artificial floating island (=AFI) for the stagnant water area which can secure exuberant landscape and water-friendility. The equipment devised in this study is designed to make up the weakness of conventional AFIs and improves the removal efficiency of pollutants using the mixture of media and plants. The air compressor positioned at the inlet releases air with inflow continuously, the water pump at the outlet sprays as a form of fountain with causing a disturbance on stable water column, then, both of them contribute improvement of water quality over a large area. We applied Bio-stone as a media in this system and performed an experiment of pre-efficiency test, and we concluded that the higher pollutants concentration of inflow, the higher removal efficiency we obtained. At the result of lab-scale experiment, in the case of high-concentration inflow, in the removal efficiency of SS is 62.2%, BOD is 50.2%, COD is 55.1%, T-N is 31.6%, T-P is 38.4%. In addition, to evaluate the field application, we set up the facilities in Sin-gal lake located in Yongin-Si Gyeonggi-Do, and researched on the removal efficiency of outflow relative to the inflow. As a result, SS is 53.5%, BOD is 32.8%, COD is 36.9%, T-N is 22.6%, T-N is 33.2%.

• Journal of The Korean Association For Science Education
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• v.36 no.4
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• pp.539-550
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• 2016

The purpose of the study is to conceptualize SSI-PCK by identifying major components and sub-components to promote science teachers' confidence and knowledge on teaching SSIs. To achieve this, I conducted extensive literature reviews on teachers' perceptions on SSI, case studies of teachers addressing SSIs, SSI instructional strategies, etc. as well as PCK. Results indicate that SSI-PCK include six major components: 1) Orientation for Teaching SSI (OTS), 2) Knowledge of Instructional Strategies for Teaching SSI (KIS), 3) Knowledge of Curriculum (KC), 4) Knowledge of Students' SSI Learning (KSL), 5) Knowledge of Assessment in SSI Learning (KAS), and 6) Knowledge of Learning Contexts (KLC). OTS refers to teachers' instructional goals and intentions for teaching SSIs. Teachers often present a) activity-driven, b) knowledge and higher order thinking skills, c) application of science in everyday life, d) nature of science and technology, e) citizenship and f) activism orientations for teaching SSIs. KIS indicates teachers' instructional knowledge required for effectively designing and implementing SSI lessons. It includes a) SSI lesson design, b) utilizing progressive instructional strategies, and c) constructing collaborative classroom cultures. KC refers to teachers' knowledge on a) connection to science curriculum (horizontal/vertical) and b) connection to other subject matters. KSL refers to teachers' knowledge on a) learner experiences in SSI learning, b) difficulties in SSI learning, and c) SSI reasoning patterns. KAS indicates teachers' knowledge on a) dimensions of SSI learning to assess, and b) methods of assessing SSI learning. Finally, KLC refers to teachers' knowledge on the cultures of a) classrooms, b) schools, and c) community and society where they are located when teaching SSIs.

• Korean Journal of Poultry Science
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• v.39 no.2
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• pp.143-149
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• 2012

This work was carried out to investigate the performance of growing period of large-type Korean native ducks. A total of four hundred twenty female and male duck chicks generated from A and B strains of ducks. Groups were four crossbreds (3 replications/crossbred, 35 birds/replication) as $2{\times}2$ factors (2 strains, A and B; 2 genders, female and male). On the body weight, male of B strains was the highest among 4 treatments after the age of 4 week (P<0.05). Body weight of B strain was higher than that of A strain at all period (P<0.05). Body weight of male was higher compared to that of female after the age of 4 week (P<0.05). On the body weight gain, male of B strain was the highest and female of A strain was the lowest among 4 treatments at 0~8, 0~12, 0~16 and 0~20 weeks (P<0.05). Body weight gain of male was higher than that of female after the age of 4 week (P<0.05). On the feed intake, male of B strain was the highest among 4 treatments from the age of 0 week and to the age of 4, 12, 16 and 20 week (P<0.05). Feed intake of male was higher than that of female at 0~12, 0~16 and 0~20 weeks (P<0.05). On the feed conversion ratio, male of B strain was the highest among other treatments 0~4 weeks and female of A strain was at 0~8 and 0~12 weeks (P<0.05). Feed intake of female was higher compared to that of female at 0~8 weeks and male was high at 0~20 weeks. These results provided the basic data on the record of growing phase of large-type Korean native ducks.

• Korean Journal of Poultry Science
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• v.40 no.3
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• pp.217-222
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• 2013

This work was carried out to investigate the performance of large-type Korean native ducks at middle laying phase (30 to 50 weeks). A total of one hundred and sixty eight laying ducks were divided into A and B strains (6 replications/strain, 14 birds/replication and fed practical diet, for 20 weeks). There was no significant difference in body weight, daily feed intake and average egg weight. With increasing rearing period, mean body weight tended to be decreased and showed the lowest value (2,649 g) at 42 weeks of age (P<0.05). Similar trend was observed for weekly feed intake and average egg weight which decreased with passing weeks and was lowest (190.5 g and 83.8 g, respectively) at the age of 42~46 weeks (P<0.05). Daily egg production of B strain was higher than that of A strain at the age of 46~50 weeks (P<0.05). Weekly egg production of A and B strains commenced to decrease from the age of 42 weeks, however, B strain recovered at 46~50 weeks of age (P<0.05). At the age of 30~38 weeks, the egg production in B strain was higher than A strain (P<0.05), whereas, there was no significant difference between both the strains during 38~50 week. Feed conversion ratio of A strain was higher than that of B strain at 46~50 weeks of age (P<0.05). Weekly feed conversion was highest at the age of 42~46 weeks (P<0.05). In conclusion, the present results provides the basic information of the performance record of large-type Korean native ducks for the middle laying phase.

• Journal of the Korea Concrete Institute
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• v.23 no.6
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• pp.711-722
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• 2011

Beam-column gravity or Intermediate Moment frames subjected to unexpected large displacements are vulnerable when no seismic details are provided, which is typical. Conversely, economic efficiency of those frames is decreased if unnecessary special detailing is applied as the beam and column size becomes quite large and steel congestion is caused by joint transverse reinforcement in beam-column connections. Moderate seismic design is used in Korea for beam-column connections of buildings with structural walls, which are to be destroyed when the unexpected large earthquake occurs. Nonetheless, performance of such beamcolumn connections may be substantially improved by the addition of steel fibers. This study was conducted to investigate the effect of steel fibers in reinforced concrete exterior beam-column connections and possibility for the replacement of some joint transverse reinforcement. Ten half-scale beam-column connections with non-seismic details were tested under cyclic loads with two cycles at each drift up to 19 cycles. Main test parameters used were the volume ratio of steel fibers (0%, 1%, 1.5%) and joint transverse reinforcement amount. The test results show that maximum capacity, energy dissipation capacity, shear strength and bond condition are improved with the application of steel fibers to substitute transverse reinforcement of beam-column connections. Furthermore, several shear strength equations for exterior connections were examined, including the proposed equation for steel fiber-reinforced concrete exterior connections with non-seismic details.

• Journal of the Korea Concrete Institute
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• v.24 no.3
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• pp.275-283
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• 2012

Steel Plate for Rebar Connection was recently developed to splice rebars in delayed slab-wall joints in high-rise building, slurry wall-slab joints, temporary openings, etc. It consists of several couplers and a thin steel plate with shear key. Cyclic loading tests on slab-wall joints were conducted to verify structural behavior of the joints having Steel Plate for Rebar Connection. For comparison, joints with Rebend Connection and without splices were also tested. The joints with Steel Plate for Rebar Connection showed typical flexural behavior in the sequence of tension re-bar yielding, sufficient flexural deformation, crushing of compression concrete, and compression rebar buckling. However, the joints with Rebend Connection had more bond cracks in slabs faces and spalling in side cover-concrete, even though elastic behavior of the joints was similar to that of the joints with Steel Plate for Re-bar Connection. Consequently, the joints with Rebend Connection had less strengths and deformation capacities than the joints with Steel Plate for Re-bar Connection. In addition, stiffness of the joints with Rebend Connection degraded more rapidly than the other joints as cyclic loads were applied. This may be caused by low elastic modulus of re-straightened rebars and restraightening of kinked bar. For two types of diameters (13mm and 16mm) and two types of grades (SD300 and SD400) of rebars, the joints with Steel Plate for Rebar Connection had higher strength than nominal strength calculated from actual material properties. On the contrary, strengths of the joints with Rebend Connection decreased as bar diameter increased and as grade becames higher. Therefore, Rebend Connection should be used with caution in design and construction.

• Journal of Radiation Protection and Research
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• v.37 no.3
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• pp.108-115
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• 2012

The Urban Areas Working Group within the EMRAS-2 ($\underline{E}$nvironmental $\underline{M}$odelling for $\underline{RA}$diation $\underline{S}$afety, Phase 2), which has been supported by the IAEA (International Atomic Energy Agency), has designed some types of accidental scenarios to test and improve the capabilities of models used for evaluation of radioactive contamination in urban areas. For the comparison of the results predicted from the different models, the absorbed doses in air were analyzed as a function of time following the accident with consideration of countermeasures to be taken. Two kinds of considerations were performed to find the dependency of the predicted results. One is the 'accidental season', i.e. summer and winter, in which an event of radioactive contamination takes place in a specified urban area. Likewise, the 'rainfall intensity' on the day of an event was also considered with the option of 1) no rain, 2) light rain, and 3) heavy rain. The results predicted using a domestic model of METRO-K have been submitted to the Urban Areas Working Group for the intercomparison with those of other models. In this study, as a part of these results using METRO-K, the countermeasures effectiveness in terms of dose reduction was analyzed and presented for the ground floor of a 24-story business building in a specified urban area. As a result, it was found that the countermeasures effectiveness is distinctly dependent on the rainfall intensity on the day of an event, and season when an event takes place. It is related to the different deposition amount of the radionuclides to the surfaces and different behavior on the surfaces following a deposition, and different effectiveness from countermeasures. In conclusion, a selection of appropriate countermeasures with consideration of various environmental conditions may be important to minimize and optimize the socio-economic costs as well as radiation-induced health detriments.