• Resources Recycling
• /
• v.6 no.1
• /
• pp.23-28
• /
• 1997

Iron and slag were prepared by melting mixed industrial wastes in an induction furnace. The wastes were steel can, limestone sludge, waste foundry sand, coal fly ash, and glasses. The effects of their mixing ratio on the charactenstics of the meltcd slag were investigated. The wastes were melted to slag under the constant basicity of 1.2. It was found that the major phases of the slag were P-C,S and C,AS and then ratio was determined by the mixing ratio af waste materials. The recovery of iron was about 93-95%. The feasibility of using the slag as the aggregate was confirmed by thc elution and campression tests.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
• /
• v.15 no.1
• /
• pp.36-43
• /
• 2004

In this paper, we proposed a novel compact microstrip lowpass filter with an ultra-wide stopband and prominent cutoff sharpness using slot on the ground plane and microstrip shunt open stub. The microstrip shunt open stub and slot exhibit the different stopband response. The combined characteristics of these structures gives the ultra-wide stopband characteristics and the coupling effect between slots on the ground plane makes the prominent cutoff sharpness. The fabricated microstrip lowpass filter with the size of 20.1 mm ${\times}$ 18.7 mm has -3 ㏈ cutoff frequency at 1.187 ㎓ and -20 ㏈ stopband from 1.33 ㎓ to over 20 ㎓ and the insertion loss in the passband is less than -0.4 ㏈ form DC to 1 ㎓.

• Korean Journal of Optics and Photonics
• /
• v.22 no.3
• /
• pp.117-121
• /
• 2011

We propose a saturable absorber reflector based on guided-mode resonance. A carbon nanotube is used as a saturable absorber. By tuning the fill factor, modulation depth can be increased without a change of height of the CNT. We investigate the reflector properties such as modulation depth, bandwidth and peak reflectance as a function of the height of the CNT and the fill factor. The advantage of the proposed reflector is that it can reduce saturation energy by 50 times compared with CNT thin film of 100~200nm.

• The Journal of the Korea institute of electronic communication sciences
• /
• v.14 no.4
• /
• pp.645-650
• /
• 2019

In this paper, a specifically designed waveguide structure that can carry first, and second-order orbital angular momentum(: OAM) mode is proposed. The proposed optical waveguide consists of three Si stripes embedded in $SiO_2$, which is suitable for implementing on-chip integration and fabrication by standard thin film deposition and etching processes. The second-order OAM mode was generated by combining two eigenmodes, which are calculated by finite difference method(: FDM). The topological charge number of the first, and second-order OAM mode was calculated as l=0.9642 and 1.8766 respectively, which is close to the theoretical value.

• Science of Emotion and Sensibility
• /
• v.20 no.1
• /
• pp.67-74
• /
• 2017

The goal of this study is to present quantification method for empathy. The micro-movement technology (non-contact sensing method) was used to identify empathy level. Participants were first divided into two groups: Empathized and not empathized. Then, the upper body data of participants were collected utilizing web-cam when participants carried expression tasks. The data were analyzed and categorized into 0.5 Hz, 1 Hz, 3 Hz, 5 Hz, 15 Hz. The average movement, variation, and synchronization of the movement were then compared. The results showed a low average movement and variation in a group who empathized. Also, the participants, who empathized, synchronized their movement during the task. This indicates that the people concentrates with each other when empathy has been established and show different levels of movement. These findings suggest the possibility of empathy quantification using non-contact sensing method.

• The Journal of the Korea institute of electronic communication sciences
• /
• v.15 no.4
• /
• pp.659-664
• /
• 2020

In this paper, we propose a silicon-based electro-optic (EO) modulator which can modulate a sign of a topological charge number l of |l|=1 orbital angular momentum (OAM) mode. The proposed EO modulator consists of position-dependent doped Si waveguide core and undoped SiO2, cladding, which enables control of the effective index and propagation loss of two OAM constitutive eigenmodes. The modulator functions as OAM mode maintaining waveguide at -0.33V and as topological charge sign inverter at 10V. The output OAM mode purity is calculated through electric field distribution, showing high purity of |l|>0.92 in both cases.

• The Southeast Asian review
• /
• v.24 no.2
• /
• pp.167-206
• /
• 2014

메콩 경제권(GMS)의 다양한 개발 현장 속에서 고무 나무로부터 채취하는 라텍스는 캄보디아, 라오스를 포함한 인도 차이나 반도 국가들 사이에서 주요 농업 활동으로 주목 받고 있다. 그러나 캄보디아와 라오스의 대형 플랜테이션은 여러 부정적인 결과들을 낳고 있다. 토지 점유, 계약 농업을 통한 착취 등으로 인해 역설적으로 농촌의 빈곤은 증가하고 있고 해외 투자자에 대한 재정적, 기술적 의존이 심화되고 환경 파괴가 일어나고 있다. 이러한 점들로 인해 소규모 자작농들에 주목할 필요가 있다. 고무 자작농은 고용을 창출하며 토지 점유를 방지한다. 본 연구는 캄보디아와 라오스의 소규모 고무 자작농들의 생계를 비교하며 고무 호황으로 어떠한 이득을 얻고 어떠한 형태로 생계를 개선할 수 있는지를 연구한다. 본 연구는 캄보디아의 Tboung Khmum 구역과 Somsanouk 마을의 사례 연구를 바탕으로 하였다. 실증적인 분석은 세 가지의 이론적 틀을 바탕으로 하였다. 미시-생계 연구, 글로벌 가치사슬 그리고 GMS에 대한 연구들이다. 실증 분석의 초점은 생계의 변화상과 결과(고용 창출과 빈곤 탈출)이다. 전체적으로 소규모 고무 자작농은 전망이 밝았으나 앞서 언급 된 문제점들로 인해 농촌 문제를 모두 해결할 수 있는 수단은 아니다. 중요한 유사성은 소규모 고무 자작농의 사회경제적 공헌이다. 연구 지역 두 곳에서 자작농들은 고무 농사는 생계를 개선하는 데에 좋은 수단이라고 답하였다. 그럼에도 불구하고 낮은 교육 수준은 그들의 생계 전략을 불안정하게 하고 있다. 양쪽 지역에서 응답자들은 다른 주민을 따라 고무 농사를 시작했다고 대답했으며 경제, 환경적인 위험에 대해 충분히 인지하고 있지 못하였다. 이와 관련한 다른 유사점으로 소규모 자작농들을 지원할 수 있는 정부의 개입이 없었다는 것이다. 자금 조달은 고무 농사의 심각한 애로 사항 중 하나였다. 명확한 차이점으로 Tboung Khmum의 자작농들은 중개 상인에게 계약 관계를 맺지 않고 라텍스를 판매했으며 Somsanouk의 경우에는 고무 가격이 국제 시장의 영향을 받음에도 가장 높은 가격을 제시하는 상인에게 농민 전체가 같이 판매를 하였다. 이러한 현상은 GMS 내에서 이루어지고 있는 근대적인 경제 현상 에 농촌 공동체들이 다양하게 연결 되고 있음을 재확인한다. 게다가 Somsanouk 마을에서는 사이짓기를 하는 경우가 없었다. 이는 투자자들이 생산량을 극대화하기 위해 자작농들에게 사이짓기를 장려하지 않았기 때문이다. Tboung Khmum 마을의 경우 고무와 더불어 고무 이전의 주요 작물이던 카사바를 같이 재배했다. 요약하면, 자작농에 의한 소규모 고무농업은 (비록 농촌의 모든 어려움을 해결할 수는 없지만) 토지점유 등 부정적 현상이 나타나는 대규모 플렌테이션에 비해 유의미한 일자리를 창출하는 등 미래를 위한 보다 나은 대안이 될 수 있다. 농촌 생활의 질을 개선하기 위해서는 7년 간의 고무 생육기간 동안 농가가 감수해야 하는 사회-경제적 불안정성을 해결하고 대안적 소득원을 마련할 필요가 있다

• Korean Journal of Community Nutrition
• /
• v.9 no.2
• /
• pp.191-203
• /
• 2004

This study was performed to compare the foodservice management practices in the employee feeding operations of Jeonnam and Chungchong area. Questionnaires were developed and mailed to 160 dietitians with management in employee foodservice of Jeonnam and Chungchong area. Completed questionnaires were received from 124 dietitians with a response rate of 77.5%. The results of this study can be summarized as follows:. Age, work experience, concurrent position and work time of dietitians were significantly higher in the Chungchong area than those in the Jeonnam area. Times of meals and amount of meals served per day in the Chungchong area were significantly higher than those in the Jeonnam area. The type of menu by foodservice operation was high non-selective menu in both areas, especially non-selective menu was high in self-operated place whereas selective menu was high in contract management. Period of cycle menu was 10-15 days in Jeonnam area, but that was 7 days in Chungchong area and so cycle menu of both areas was significantly different (p ＜ 0.001). Most considerable factor in menu planning was preference in Jeonnam area and was cost in the Chungchong area. Food purchasing method was used mostly by automatic computerized order in the Jeonnam area whereas telephone or mail order was high in the Chungchong area.

• Science of Emotion and Sensibility
• /
• v.22 no.1
• /
• pp.45-54
• /
• 2019

Empathy has been observed to be pivotal in enhancing both social relations and the efficiency of task performance. Empathetic interaction has been shown to begin with individuals mirroring each other's facial expressions, vocal tone, actions, and so on. The internal responses of the cardiovascular activity of people engaged in empathetic interaction are also known to be synchronized. This study attempted to objectively and quantitatively define the rules of empathy with regard to the synchronization of cardiac rhythm between persons. Seventy-four subjects participated in the investigation and were paired to imitate the facial expressions of their partner. An electrocardiogram (ECG) measurement was taken as the participants conducted the task. Quantitative indicators were extracted from the heart rhythm pattern (HRP) and the heart rhythm coherence (HRC) to determine the difference of synchronization of heart rhythms between two individuals as they pertained to empathy. Statistical significance was confirmed by an independent sample t-test. The HRP and HRC correlation(r) between persons increased significantly with empathy in comparison to an interaction that was not empathetic. A difference of the standard deviation of NN intervals (SDNN) and the dominant peak frequency decreased. Therefore, significant parameters to evaluate empathy have been proposed through a step-wise discrimination analysis. Empathic interactions may thus be managed and monitored for high quality social interaction and communication.

• Korean Chemical Engineering Research
• /
• v.52 no.6
• /
• pp.821-825
• /
• 2014

Steam gasification of sawdust char was performed in a thermobalance reactor at high temperature. Gasification temperature was changed from $850^{\circ}C$ to $1400^{\circ}C$ and steam partial pressure was 0.3, 0.5 and 0.7 atm. Three models of gas-solid reaction were applied to the reaction kinetics analysis and modified volumetric model was an appropriate model. Reaction control regime and diffusion control regime were distinct depending on the temperature. Apparent activation energy and pre-exponential factors for both of the regimes were evaluated and the effects of steam partial pressure were examined. $H_2$ concentration in the produced gas was two times higher than that of CO due to the gasification accompanying by the water gas shift reaction.