• Bulletin of the Korean Chemical Society
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• 제20권6호
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• pp.667-671
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• 1999

A series of the para-substituted 7-aryl-norbornadienyl cation (3) was prepared in FSO3H/SO2ClF solution at -100℃ and their 13C NMR shifts were measured at -80℃. The plots of the chemical shifts (changes in chemical shifts) of cationic carbon, ΔδC+, aganist our calculated new substituent constant, σc+s, gave an excellent correlation (r=0.994), with a ρc+ value of 12.63. These results indicate that the new substituent constants, σc+s, can be successfully employed to compare the relative charge demand of the carbonium ion by π-and πσ-participation.

• 디지털융복합연구
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• 제17권7호
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• pp.131-138
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• 2019

전 세계 전력 생산 에너지의 비율은 석탄이 40%, 천연가스 20%, 수력 16%, 원자력 15%, 석유 6%로 모두가 환경오염을 유발하는 에너지다. 또한 화석연료는 지구상에 자원의 편중이 심하기 때문에 가격과 공급면에서 심각한 문제를 야기한다. 이러한 문제로 화석 연료를 대체하게 될 차세대 친환경 에너지로써 태양광 에너지가 각광 받고 있다. 이에 본 연구에서는 국내 공단에 Test-Bed를 선정하여 수용가의 대응용 태양광 ESS 시스템 적용함에 있어 Peak-cut 운영을 위한 Charge Operation Plan과 Discharge Operation Plan 운영방안을 최대수요전력 감소 시뮬레이션을 통해 검증하고자 한다. 이를 위해 전력사용량이 가장 많은 11월부터 2월의 전력사용량을 선정하여 Charge/Discharge Logic을 적용했다. 본 논문에서 제시한 충전/방전 로직에 따른 시뮬레이션 결과, ESS Peak-cut 서비스 이후의 최대수요전력이 감소하였으며 Peak-target 전력의 50%로 감소함에 따라 계약전력 또한 감소함을 알 수 있다. 이를 통해 계약전력 감소는 해당 수용가의 기본 전력 값을 감소시켜, 경제적 우월성을 기대할 수 있을 뿐만 아니라 전기품질 향상 및 전력공급시스템의 안정화에도 기여할 수 있을 것으로 판단된다.

• 한국컴퓨터정보학회논문지
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• 제24권3호
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• pp.29-39
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• 2019

In this study, we introduce a model that satisfies energy efficiency and economical efficiency by introducing and demonstrating cogeneration generators in industrial complexes using various actual data collected at the site. The proposed model is composed of three scenarios, ie, full - time operation, scenario operated according to demand, and a fusion type. In this study, the power generation profit and surplus thermal energy are measured according to the operation of the generator, and the thermal energy is traded according to the demand of the customer to calculate the profit and loss including the heat and evaluate the economic efficiency. As a result of the study, it is relatively profitable to reduce the generation of the generator under the condition that the electricity rate is low and the gas rate is high, while the basic charge is not increased. On the contrary, if the electricity rate is high and the gas rate is low, The more you start up, the more profit you can see. These results show that even a cogeneration power plant with a low economic efficiency due to a low "spark spread" has sufficient economic value if it can sell more than a certain amount of heat energy from a nearby customer and adjust the applied power through peak management.

• 한국응용과학기술학회지
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• 제33권2호
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• pp.385-390
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• 2016

연구에서 나노 알루미나와 마그네지아의 첨가에 의한 304 스테인레스 스틸에 $170^{\circ}C$ 2시간 열 경화시켰다. 레이저유도 분광학에 의한 코팅된 시료를 전하결합 장치와 SEM을 활용한 장치를 설계하여 시험 측정하였다. 이 결과 나노 알루미나와 마그네지아가 함유된 세라믹 코팅이 나노 무기화합물이 함유되지 않은 시료보다 부착성, 내스크래치성이 우수하였으며, 또한 산용액속에서 시료의 질량감소의 변화가 매우 작았다. 그리하여 본 연구는 304 스테인레스 스틸의 내부식성을 개선하기 위해 시료가 코팅되었으며, 분석공정이 설계되어 고분해능 CCD와 함께 분석되었다. 요즈음, 스테인레스 스틸의 코팅은 산업에 특이응용이 발전됨에 따라 위생학, 우주항공, 기기장치, 관측 등의 분야 등에 산업적 요구가 증가되고 있다.

• 한국세라믹학회지
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• 제49권6호
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• pp.631-636
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• 2012

Conventional SONOS (poly-silicon/oxide/nitride/oxide/silicon) type memory is associated with a retention issue due to the continuous demand for scaled-down devices. In this study, $Al_2O_3/Y_2O_3/SiO_2$ (AYO) multilayer structures using a high-k $Y_2O_3$ film as a charge-trapping layer were fabricated for nonvolatile memory applications. This work focused on improving the retention properties using a $Y_2O_3$ layer with different tunnel oxide thickness ranging from 3 nm to 5 nm created by metal organic chemical vapor deposition (MOCVD). The electrical properties and reliabilities of each specimen were evaluated. The results showed that the $Y_2O_3$ with 4 nm $SiO_2$ tunnel oxide layer had the largest memory window of 1.29 V. In addition, all specimens exhibited stable endurance characteristics (program/erasecycles up to $10^4$) due to the superior charge-trapping characteristics of $Y_2O_3$. We expect that these high-k $Y_2O_3$ films can be candidates to replace $Si_3N_4$ films as the charge-trapping layer in SONOS-type flash memory devices.

• Advances in materials Research
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• 제8권1호
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• pp.37-46
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• 2019

Electrochemical double layer capacitors (EDLCs) which are fabricated using carbon based electrodes have been emerging at an alarming rate to fulfill the energy demand in the present day world. Activated charcoal has been accepted as a very suitable candidate for electrodes but its cost is higher than natural graphite. Present study is about fabrication of EDLCs using composite electrodes with activated charcoal and Sri Lankan natural graphite as well as a gel polymer electrolyte which is identified as a suitable substitute for liquid electrolytes. Electrochemical Impedance Spectroscopy, Cyclic Voltammetry and Galvanostatic Charge Discharge test were done to evaluate the performance of the fabricated EDLCs. Amount of activated charcoal and natural graphite plays a noticeable role on the capacity. 50 graphite : 40 AC : 10 PVdF showed the optimum single electrode specific capacity value of 15 F/g. Capacity is determined by the cycling rate as well as the potential window within which cycling is being done. Continuous cycling resulted an average single electrode specific capacity variation of 48 F/g - 16 F/g. Capacity fading was higher at the beginning. Later, it dropped noticeably. Initial discharge capacity drop under Galvanostatic Charge Discharge test was slightly fast but reached near stable upon continuous charge discharge process. It can be concluded that initially some agitation is required to reach the maturity. However, the results can be considered as encouraging to initiate studies on EDLCs using Sri Lankan natural graphite.

• 근관절건강학회지
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• 제28권1호
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• pp.18-29
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• 2021

Purpose: This study examined the knowledge and education needs of nurses in charge of adequacy evaluation in small and medium-sized hospitals. Methods: Study participants included 198 nurses in charge of adequacy evaluation in small and medium-sized hospitals. Data were collected from November 19 to 28, 2020 through an online survey. The data were analyzed by independent t-test and one way ANOVA analysis using the SPSS. Results: The knowledge score for the adequacy evaluation of small and medium-sized hospitals was 11.61±4.10 (total of 20 points), and the educational demand was 3.87±0.88 points on a 5-point scale. Regarding the necessity of education for adequacy evaluation of small and medium-sized hospitals, 80.3% of the participants claimed education as being necessary. "Online video lectures" were the most preferred (22.7%) education method, and "2 times" was the most frequent education (47.0%); "1 hour" was the usual duration of class (48.5%). Conclusion: It is necessary to develop and apply an educational program reflecting the measure of educational needs to improve the knowledge level of nurses in charge of adequacy evaluation in small and medium-sized hospitals.

• 대한토목학회논문집
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• 제26권1D호
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• pp.49-58
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• 2006

본 연구는 도시개발밀도와 교통시설용량 간의 영향관계를 실증적으로 분석하여, 교통성과(transportation performance)를 극대화하기 위한 토지이용방안을 모색하는 것이다. 이를 위해 서울시 도심을 사례분석지역으로 선정하여 다양한 개발밀도 시나리오에 따라 교통용량의 한계를 감안한 개발용량을 산정하였다. 개발밀도 변화에 따른 교통영향분석을 위한 분석모형으로 SECOMM모형이 제시되었고, 이를 활용하여 20개의 다양한 개발밀도 대안의 영향을 분석하였다. 분석 결과, 도심고밀개발시교통 관점에서 볼 때 분석상 교통적으로 가장 지속가능성이 높은 수준은 도심혼잡통행료를 징수하고 용적률을 460% 까지 개발했을 때인 것으로 나타났다. 한편 도심용적률이 460%를 상회해도 서울시 전체적인 교통상황이 지속적으로 개선되는 것으로 분석되어, 통행료 수준을 높임으로써 지속가능한 교통여건을 달성하는 것이 보다 바람직할 것으로 판단된다. 한편, 도심에서 혼잡통행료를 부과하지 않는다면 도심에서 최대 용적률 430%까지 밖에 고밀화를 진행할 수 없고 이때 서울시 전체적으로 개선폭도 그리 크지 않은 것으로 분석되었다. 따라서 도심고밀화를 위해서는 교통수요관리시책(TDM)과 병행하는 것이 필수적일 것으로 사료된다.

• 한국간호교육학회지
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• 제4권2호
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• pp.131-146
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• 1998

The study was attempted and executed to reach the following conclusions. The period was May 1st through June 15th, 1998 and the subjects were 302 teachers consisting of School Nurses and general teachers in Pusan city. 1) The degrees of recognition of sexual roles by the subjects were compared as follows : The average point as to the recognition of sexual roles in the occupational functions by the school nurses was 2.41, higher than that of the general teachers. The average points as to the recognition of sexual roles in the attitudes by the school nurses was 2.28, higher than that of the general teachers. The average points as to the recognition of sexual roles in the abilitis was 2.26, higher than that of the general teachers. These ascertain that school nurses recognize the man has higher superities in the occupational functions, the attitudes and the abilities than the woman. 2) The degrees of demand of sexual education by the subjects were compared as follows : As to the degrees of demand of sexual education, the school nurses showed higher demand than the general teachers in the concepts such as 'the society and sexualities, physiology and actual education'. 3) The levels of the consciousness of sexual education by the subjects were compared as follows : the general teachers showed the more strict attitudes than the school nurses against the lascivious sex objects and wanted the punishment against the related students and the general teachers have myth. They claimed that their family have no relation with the sexual violence or pornography. As to the masturbation, the general teachers showed the more conservative attitudes. 4) The opinions by the subjects as to the well-qualified person in charge of sexual education in school were compared as follows : 77.3% of the school nurses, and 36.1% of the general teachers supported the school nurses.

• 전기학회논문지
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• 제67권10호
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• pp.1278-1285
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• 2018

For saving electricity bill, energy storage system(ESS) is being installed in factories, public building and commercial building with a Time-of-Use(TOU) tariff which consists of demand charge(KRW/kW) and energy charge(KRW/kWh). However, both of peak reduction and ESS special tariff are not considered in an analysis of initial cost payback period(ICPP) on ESS. Since it is difficult to reflect base rate by an amount of uncertain peak demand reduction during mid-peak and on-peak periods in the future days. Therefore, the ICPP on ESS can be increased. Based on this background, this paper presents the advanced analysis method for the ICPP on ESS. In the proposed algorithm, the representative days of monthly electricity consumption pattern for the amount of peak reduction can be found by the k­means clustering algorithm. Moreover, the total expected energy costs of representative days are minimized by optimal daily ESS operation considering both peak reduction and the special tariff through a mixed-integer linear programming(MILP). And then, the amount of peak reduction becomes a value that the sum of the expected energy costs for 12 months is maximum. The annual benefit cost is decided by the amount of annual peak reduction. Two simulation cases are considered in this study, which one only considers the special tariff and another considers both of the special tariff and amount of peak reduction. The ICPP in the proposed method is shortened by 18 months compared to the conventional method.