• International Journal of Industrial Entomology and Biomaterials
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• v.45 no.2
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• pp.84-92
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• 2022

White-Jade silkworm (previously also known as Baegokjam) variety is the most popular silkworm variety that produces white cocoons. In 2021, the market share of White-Jade variety in Korea is very high, accounting for 88% of the silkworm production. Daebaekjam, Dodamsilkworm, Kumkangjam, and Kumokjam varieties, which have recently been established, make white cocoons like White-Jade. In this study, we found that 5 types of HongJams produced from 5 varieties of silkworms producing white cocoons did not show any severe difference in proximate analysis. The amounts of crude proteins, the most abundant nutrient, were between 71.05 ~ 73.38%, and those of crude lipids were 13.89 ~ 14.69% in 5 types of HongJams. In addition, there was no difference between White-Jade HongJam (WJ) and Daebaekjam HongJam in amino acid compositions. The amount of unsaturated fatty acid was significantly higher in WJ than in the other four types of HongJams, but the omega-6 fatty acids/omega-3 fatty acids ratio was higher in the four types of HongJams. Most of the minerals were higher in four types of HongJams than in WJ, and three heavy metal were not detected in all 5 types of HongJams. Phytochemicals were also most abundant in WJ, but the difference in the amounts were not severe. And pepsin digestibility was the highest for Kumokjam HongJam and the lowest for Dodam-silkworm HongJam, but the difference was not severe. The nutritional component analysis results of this study suggested that four new varieties can be used for producing HongJams, and Daebaekjam can replace White-Jade the most as the protein source.

• Journal of the Korean Recycled Construction Resources Institute
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• v.10 no.4
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• pp.523-530
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• 2022

The problem in the construction of seawall reinforcing the seawall where there is seawater flow is the outflow of materials. Gravity-type pouring of concrete is difficult to fill the voids smoothly, and the cement of concrete that has not hardened is likely to be dispersed in seawater. This phenomenon not only reduces the reliability of quality after concrete hardening, but can also adversely affect the surrounding environment. Therefore, there is a need for a gel-like injection material that can be injected, In this study, the initial strength and durability improvement effect of seawater immersion were evaluated by using electrofurnace reduction slag and blast furnace slag with acute properties. As a result of the experiment, it was possible to prepare a gel-like injection material having flowability through reaction with silica-based chemical liquid. The flowability of the gel is 105~143 mm depending on the formulation, and the on-site simulation test can fill the voids without external leakage, confirming its on-site applicability.

• Resources Recycling
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• v.33 no.1
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• pp.37-47
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• 2024

In grouting, the LW method is commonly employed to induce the gelation of cementitious material using water glass, thereby restricting the extent of material injection. Nevertheless, challenges manifest when materials are lost before gelation, particularly in regions with high groundwater flow rates or significant subsurface voids. This study developed a thixotropic grout material using LFS and GGBFS to mitigate material loss during injection, with an assessment of its flow characteristics, durability in marine exposure, strength, and injection properties. The outcomes revealed that the thixotropic grout material exhibited flow ranging from 105 to 143 mm and enhanced strength and durability compared to the LW method. Furthermore, field tests substantiated that applying vibration and impact improved impermeability.

• Proceedings of the KAIS Fall Conference
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• 2009.12a
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• pp.871-873
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• 2009

기존의 연직 배수공법은 통수능의 저하, 막힘현상(clogging) 등으로 인하여 연약지반의 압밀을 지연시키는 문제점을 가지고 있다. 이 연구에서는 고분자 압전소자인 PVDF(polyvinylidene fluoride)를 연직배수공법에 적용하여 연직배수공법의 기존 문제점을 극복하고 연약지반의 간극수를 빠르게 소산시킴으로서 압밀을 촉진 시킬 수 있을 것이라 판단되어 이에 따른 실내 실험을 수행하였다. 실험 결과 PVDF를 적용한 경우에서 그렇지 않은 경우보다 간극수의 배출량이 증가하여 PVDF의 적용으로 배수재의 성능이 향상됨을 알 수 있었다.

• Proceedings of the KAIS Fall Conference
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• 2009.12a
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• pp.868-870
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• 2009

이 연구에서는 암반에 마이크로 파일을 그라우팅하여 시공할 경우에 암반과 그라우트 접촉면에 발생되는 부착력을 특수 제작된 부착력실험용 몰드와 만능시험기를 이용하여 측정하고 그라우팅 방법(압력식, 중력식)을 달리하여 비교 분석하였다. 실험결과 압력식의 부착력과 일축압축강도가 중력식보다 크게 나타났다.

• Proceedings of the Korean Geotechical Society Conference
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• 2008.03a
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• pp.689-696
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• 2008

In this study, seepage characteristics of breakwater in dredging ground evaluated for the piping stability estimation by scale model tests. For this, to estimated the seepage characteristics through the model tests and numerical analyses, the engineering stability on piping of breakwater evaluated based on scale model tests and numerical analyses results.

• Proceedings of the Korean Geotechical Society Conference
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• 2010.03a
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• pp.543-552
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• 2010

Due to increase in urban tunnelling as urban population and traffic volume increase, problems related with site security and civil appeal also increase. This paper presents a comparative analysis between conventional 2-arch tunnel method and non-pilot 2 arch tunnel method, which were performed in the basic design of Wie-Rae region. According to the analysis results, non-pilot 2-arch tunnel method is more efficient in terms of stability, constructability, and economic aspect. It is authors' wish that design procedure and method presented in this paper could help the design and construction of non-pilot 2-arch tunnel that should be planned in the near future.

• Proceedings of the Korean Geotechical Society Conference
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• 2004.03b
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• pp.985-994
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• 2004

The application of the reinforced retaining wall has increased in the last 10 years in Korea. The height of reinforced wall is generally limited to less than 15m. It has been reported that the reinforced wall higher than 10m should have higher strength reinforcement or should reduce the lateral earth pressure of the reinforced wall to secure the stability of the wall. In this study, the reinforced retaining wall was constructed 14m high, backfilled by a mixture of soil and cement and instrumented on the reinforcement elements. The instrumented reinforced wall was monitored during and after construction. Field monitoring result shows that a backfill by a mixture of soil and cement reduced the tensile stress developed on the reinforcing elements and the reinforced wall backfilled by a mixture of soil and cement performed successful.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.45 no.1
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• pp.20-27
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• 2008

In this paper, a nonlinear classifier of a feed-forward neural network is implemented on an FPGA chip. The feedforward neural network is implemented in hardware for fast parallel processing. After off line training of neural network, weight values are saved and used to perform forward propagation of neural processing. As an example, AND and XOR digital logic classification is conducted in off line, and then weight values are used in neural network. Experiments are conducted successfully and confirmed that the FPGA neural network hardware works well.

• Journal of Electrical Engineering and Technology
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• v.12 no.3
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• pp.1257-1261
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• 2017

This paper focuses on understanding the interrupting capability of an arc contact system in a molded case circuit breaker (hereafter MCCB). We selected four types of MCCBs and analyzed the magnetic flux density distributions in the contact systems caused by the fault currents. We ascertained that the magnetic flux density profile varies according to the shape of the contact system and was asymmetric at both the ends of an arc, perpendicular to the arc column because of the magnetic grid installed in the contact system. The asymmetric difference creates a magnetic force that pushes the arc current outwards and provides an interrupting capability. We have introduced a simple analysis method for determining the interrupting capability of the contact system for an MCCB by the arc-driving magnetic flux density.