Microalgae are efficient fatty acid producers owing to their high photosynthetic activities. They can act as sources of biofuel, feed, and various bioactive compounds. This study aimed to determine optimal culture conditions, including culture medium, temperature, and light intensity, to enhance the biomass and fatty acid content of the indigenous freshwater microalga, Tetradesmus obliquus. Evaluation using a high-throughput photobioreactor revealed that the optimal culture temperature and light intensity were 25°C and 300 μmol m-2 s-1, respectively. Additionally, we optimized components (N, P, and Mg) of the BG-11 medium to enhance the microalgal biomass. Modified BG-11 medium increased the T. obliquus biomass by 37% compared to the standard BG-11 medium. Subsequently, the culture medium was replaced with N- and P-depleted media to determine the abiotic stress factor that could increase the cellular fatty acid content. Notably, fatty acid content was significantly increased from 8.5% up to 14.6% on day 7 of culture in N-deficient (N-P+ and N-P-) media. Sequential optimization effectively increased the biomass by 83% and fatty acid content by >76% in T. obliquus. Our optimization method can be used to enhance the biomass and fatty acid contents of various other microalgae.

아토피 피부염은 만성 염증을 동반한 알레르기성 질환 이며, 일반적으로 Type 2 염증 반응과 관련이 깊다고 알 려져 있다. Corchorus olitorius (C. olitorius)의 아토피 피 부염 치료 효과를 확인하기 위하여 2,4-dinitrochlorbenzene 로 아토피 피부염 모델을 유도한 BALB/c 마우스를 대상 으로 피부 염증 개선도를 육안으로 확인하였으며, 질환 관 련 IgE와 사이토카인(IL-4, IFN-γ and TNF-α)의 수준을 측정 하였다. 7일간의 투여기간동안 양성대조약물인 Dexamethasone 투여군의 체중은 감소하였던 반면에 모든 C. olitorius 투 여군의 체중은 꾸준히 증가하였다. 이와 같은 결과는 C. olitorius이 동물에 위해한 영향이 없었다는 것을 의미한다. C. olitorius 200 mg/kg/day 투여군의 치료 효과가 가장 뛰 어났으며, 모든 C. olitorius 투여군의 염증 관련 면역글로 불린과 사이토카인의 수준은 감소하였다. 따라서, C. olitorius 는 아토피 치료제로 충분히 활용될 수 있다고 판단된다.

Chironomid larvae in drinking water treatment plants (DWTPs) and tap water lead to highlights the urgent need for effective control measures. The use of combined disinfectant treatments is becoming increasingly common to achieve optimal disinfection efficiency while minimizing residual contamination. This study was conducted to study the effect of combined treatment of disinfectants used in DWTPs on the biological control potential of chironomid larvae. In the experiment, Glytotendipes tokunagai larvae reared according to OECD guidelines were exposed to NaOCl, UV, and O3 complex substances, and biological responses were analyzed using survival rate and body color change as key indicators for 24 hours. The survival rate of larvae exposed to combined disinfectants mostly decreased in a time- and concentration-dependent manner, and lightening of body color was observed. The most significant decrease (53%) of the survival rate was observed to a combination of UV and 4 ppm NaOCl disinfectants and body color change also showed a statistically significant difference compared to the control group (P<0.001). The change in body color is suggested to be a physiological change caused by oxidation of hemoglobin due to exposure to disinfectant complexes. The results of this study contribute to determining the biological impact of combined disinfectant treatment on chironomid larvae of DWTPs, and can be used as data to suggest the biological control potential of disinfectants. In addition, it will provide important information for setting standards for combined disinfectant treatment to improve water quality in the future.

Time-series and spatial analysis of collected odor complaints in Seoul megacity during 2014~2021 were conducted for the characterization of odor complaints emitted from the living environment. The ratio of odor complaints in the environmental complaints was 16.7%, and odor complaints increased 3.3 times from 9,053 cases in 2014 to a maximum of 29,425 cases in 2019. In the time-based evaluation (monthly, daily (day of the week), and hourly variations), the highest number of complaints occurred in June, Monday, and 9:00 AM, respectively. While the lowest number of complaints occurred in December, Sunday, and 3:00 AM, respectively. Among 25 provinces in Seoul megacity, the odor complaints that occurred from 2014 to 2021 were concentrated in Eunpyeonggu. The odor complaints of Seodaemun-gu and Nowon-gu occurred at the highest levels in January-February and June, respectively. Based on the characteristics of odor complaint occurrence according to the above time-series and spatial analyses, more effective odor management and control can be implemented by focusing on those hotspot areas and specific time periods.

최근 지구온난화로 인해 폭우, 눈 등 이상기후가 발생하면서 노면 동결(블랙아이스)로 인한 사고 및 인명피해가 늘어나고 있 는 것이 문제가 되고 있다. 이를 최소화하기 위해 본 연구에서는 다공성 골재인 팽창점토에 열저장이 가능한 상변화물질(PCM)을 적용 하였다. PCM은 상변화 과정에서 열에너지를 흡수, 저장, 방출할 수 있는 소재로 온도에 따른 결빙을 최소화할 수 있다. 따라서 본 연 구에서는 시멘트 복합재에 적용되는 PCM 함침이 가능한 경량골재에 진공함침을 실시하고 기계적, 열적 성능 검증 연구를 수행하였다. 열적 성능을 향상시키기 위해 다중벽탄소나노튜브(MWCNT)와 실리카흄을 첨가하였다. 본 연구에서는 물체의 열적 성능을 측정할 수 있는 DSC 실험을 통해 PCM 함침 경량골재 및 콘크리트 복합체의 열적 성능을 검증하였다. 콘크리트 복합체 제작 후 압축강도 시험 과 열적 성능시험을 실시하였다. 이때 열적 성능을 검증하기 위해 항온항습 챔버를 이용하여 시험을 진행하였다. 압축강도 실험을 통 해 MWCNT의 분삭액을 혼입한 PCM 함침 팽창점토가 적용된 콘크리트 복합체의 평균 압축강도는 24MPa 이상으로 구조물에 적용이 가능함을 확인하였다. 열적 성능시험을 통해 PCM 함침 팽창점토가 적용된 콘크리트 복합체는 영하의 외기온도에서도 영상의 온도를 유지할 수 있음을 확인하였다. 이와 같은 결과를 통해 주거 및 상업 건물 및 다양한 구조물에 적용이 가능할 것으로 판단된다.

As environmental concerns escalate, the increase in recycling of aluminum scrap is notable within the aluminum alloy production sector. Precise control of essential components such as Al, Cu, and Si is crucial in aluminum alloy production. However, recycled metal products comprise various metal components, leading to inherent uncertainty in component concentrations. Thus, meticulous determination of input quantities of recycled metal products is necessary to adjust the composition ratio of components. This study proposes a stable input determination heuristic algorithm considering the uncertainty arising from utilizing recycled metal products. The objective is to minimize total costs while satisfying the desired component ratio in aluminum manufacturing processes. The proposed algorithm is designed to handle increased complexity due to introduced uncertainty. Validation of the proposed heuristic algorithm's effectiveness is conducted by comparing its performance with an algorithm mimicking the input determination method used in the field. The proposed heuristic algorithm demonstrates superior results compared to the field-mimicking algorithm and is anticipated to serve as a useful tool for decision-making in realistic scenarios.

이 연구는 금융교육 표준안 활용 경험이 있는 초등교사의 금융교육 표준안 활용의 어려움을 기술 및 분석한 후 금융교육 표준안 개정에 대한 시사점을 제언하고자 수행되었다. 연구를 수행하기 위해 A 연구회의 금융교육 교육과정 개발에 참여한 초등교사 14명을 연구 참여자 로 선정하였고, 심층면담을 통해 자료를 수집한 후 질적 분석을 수행하였다. 분석을 수행한 결과 교사들이 경험한 금융교육 표준안 사용의 어려움을 네 가지 범주로 분류하였고 이는 다음과 같다. 첫째, 교사들은 초등학생의 수준이 고려되지 않은 금융교육 표준안의 단일한 성취기준에 의해 어려움을 겪었다. 둘째, 교사들은 성취기준 진술 방식으로 인해 자율성이 제한되는 경험을 했다. 셋째, 교사들은 금융교육 표준안의 일부 교수학습 방법 및 유의사항 에서 실질적인 도움을 받지 못해 어려움을 겪었다. 넷째, 교사들은 수업을 설계하면서 성취 기준 내용의 중첩으로 인해 어려움을 겪었다. 이를 토대로 본 연구에서는 향후 금융교육 표준안 개정에 대한 시사점을 제언하였다.

본 연구는 도로 노면의 결빙을 방지하기 위해 열적 특성을 갖는 콘크리트를 개발했습니다. 팽창 점 토에 상변화 물질(PCM)을 함침 시키고, 고열 전도성 에폭시와 실리카 흄으로 이중코팅을 하여 PCM 물질의 유출 방지, 골재의 부착성 개선, 열적 성능 개선을 하였으며 이를 DSC를 통해 열적 성능 평가 를 진행하여 확인했습니다. 또한 상변화 물질과 경량골재의 사용으로 인한 강도 감소 개선을 위한 CNT 혼합으로 강도 감소를 25% 개선하였습니다.

Restraints of Branch Lines are used as earthquake-resistant support devices for fire-fighting pipes along with sway brace devices. The central types are aligned and fixed in a straight line with center of the pipe, but the eccentric types are fixed to on side of the pipe, so a bending moment occurs. In this study, three specimens each of central type and eccentric type were installed at an angle of 45° from the vertical and a monotonic compression load of 1340N was applied. All central type samples satisfied 17.8mm of the allowable displacement, but all eccentric type samples failed to meet the target load and buckled. Therefore, when considering the performance of eccentric type restraints, both compressive load and bending moment must be considered. Even through material mechanics calculations, the yield stress of eccentric type - 3/8 inch all threaded steel bolt - exceeds 320Mpa of the allowable stress. A experiment standards need to be established for eccentric type restraints.

UV and O3 are materials used in the water treatment process, and many studies have been reported to remove organic matters, contaminants, and microorganisms. In this study, we were investigated effects of Chirnomidae (Chironomus flaviplumus, Chironomus riparius), which are contamination indicator species to exposure UV and O3 for the survival rate, body color change and gene expression response. The survival rate of C. flaviplumus exposed to UV decreased to about 70% after 24 hours, and C. riparius about 50%. There was no change in the survival rate of C. flaviplumus exposed to O3, and C. riparius decreased to 95% after 10 minutes of exposure, but there was no change during the subsequent exposure time. In addition, UV and O3 exposure to the two species in body color faded in a time-dependent. In the HSP70 gene expression, C. riparius showed an increase in expression after UV exposure compared to the control group, and a significant difference was shown 12 hours after exposure (P<0.05). C. flaviplumus exposed to O3 showed a relatively low expression compared to the control group, and showed a significant difference at 10 minutes and 1 hour after exposure (P<0.05). These results reported the ecotoxicological effects on Chironomidae according to UV and O3 exposure. Therefore, the results of this study can be used as basic data to understand the effects of UV and O3, which are disinfectants used in water treatment plants, on Chirnomidae entering plants. Key words: Chironomus flaviplumus, Chironomus riparius, UV, O3, acute toxicity, survival

Cadmium (Cd), a heavy metal found in the aquatic environment, accumulates in organisms through the food chain. In the study, we investigated the survival rates, measurement of body Cd levels, and expression analysis of the stress response genes (Heat shock protein 70: HSP70 and Heat shock protein 60: HSP60) and antioxidant enzyme Glutathione S-Transferases (GST) on benthic oligochaete worm Tubifex tubifex exposed three concentrations of Cd, to analyze the bioaccumulation and changes of stress gene expressions to exposure toxicity of the Cd-spiked sediment. Survival rates of T. tubifex exposed to the Cdspiked sediment were 93% at 0.4 mg kg-1 Cd, 96% at 1.87 mg kg-1 Cd, and 93% at 6.09 mg kg-1 Cd for 10 days. Cd concentration in the body of T. tubifex was higher than that in the sediment. After Cd exposures for 10 days, the body Cd levels were 18.4 mg kg-1, 13.06 mg kg-1, and 79.11 mg kg-1 at exposed three concentrations of Cd, respectively. Upregulation of HSP70 gene expression was observed at all concentrations of exposed Cd as a time-dependent manner, whereas transcriptional expression of the HSP60 gene increased as a timedependent manner in T. tubifex exposed to the relative high concentration (6.09 mg kg-1) of Cd. However, GST gene expression increased on day 1 at all concentrations after Cd exposures, and then downregulated until 10 days. These results indicate to ecotoxicological and molecular effects in benthic oligochaete worm T. tubifex to Cd-spiked sediment and provide the basic information for the utilization of environmental toxicity assessment using the T. tubifex as a aquatic pollution indicator species.

In the realm of dental prosthesis fabrication, obtaining accurate impressions has historically been a challenging and inefficient process, often hindered by hygiene concerns and patient discomfort. Addressing these limitations, Company D recently introduced a cutting-edge solution by harnessing the potential of intraoral scan images to create 3D dental models. However, the complexity of these scan images, encompassing not only teeth and gums but also the palate, tongue, and other structures, posed a new set of challenges. In response, we propose a sophisticated real-time image segmentation algorithm that selectively extracts pertinent data, specifically focusing on teeth and gums, from oral scan images obtained through Company D's oral scanner for 3D model generation. A key challenge we tackled was the detection of the intricate molar regions, common in dental imaging, which we effectively addressed through intelligent data augmentation for enhanced training. By placing significant emphasis on both accuracy and speed, critical factors for real-time intraoral scanning, our proposed algorithm demonstrated exceptional performance, boasting an impressive accuracy rate of 0.91 and an unrivaled FPS of 92.4. Compared to existing algorithms, our solution exhibited superior outcomes when integrated into Company D's oral scanner. This algorithm is scheduled for deployment and commercialization within Company D's intraoral scanner.

스타트업은 10명 내외의 직원으로 구성되고 빠른 업무 진행을 위해 CEO와 직접 소통하는 경우가 많다. 또한, 직원 대부분이 소규모 공간에서 근무하기 때문에 모든 직원의 행동을 관찰할 수 있는 특성을 가지 고 있다. 이러한 환경은 CEO가 자신보다 어느 직원과 더 친밀한 관계를 형성하고 있는지 비교할 수 있는 데, 사회적 비교가 어떤 메커니즘을 통해 직원 행동에 영향을 미치는지에 대한 연구는 아직 초기에 머물 러 있다. Vidyarthi 등(2010)은 리더-멤버 교환관계의 사회적 비교(LMXSC)가 조직시민행동에 영향을 준다는 것을 밝히면서 LMXSC와 조직시민행동 간 메커니즘을 밝히는 것이 필요하다고 하였다. 이에 본 연 구는 사회 정체성 이론을 결합하여 LMXSC가 조직시민행동에 영향을 미치는 과정에서 자존감과 조직 동일시가 다중 직렬 매개 역할을 하는지 확인하고자 하였다. 연구 결과 첫째, LMXSC는 조직시민행동에 정적인 효과를 가지며, 자존감과 조직 동일시는 LMXSC와 조직시민행동 사이를 매개하였다. 둘째, 다중 직렬 매개 분석 결과 LMXSC와 조직시민행동 사이에 자존 감과 조직 동일시가 순차적으로 매개하는 것으로 나타났다. 본 연구는 LMXSC가 높은 직원은 자존감이 형성되고, 이는 조직 동일시를 거쳐 조직시민행동에 영향을 준다는 점을 밝힘으로써 창업자가 직원과 관 계를 맺을 때 고려해야 할 점과 인사 실무에서 직원 리더십 관리 및 개발, 정서 관리, 자발적 긍정 행동 증대에 필요한 인사이트를 제공한다.