• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.12
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• pp.938-943
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• 2018

Thin nano-sized fibres were prepared by an electrospinning method. The spinning appratus consisted of pump for polymer injection, nozzle and nozzle rotus, and an aluminum plate collected the polymer fibers. Its surface was chemically modified for selective improved adsorption of carbon monoxide at indoor level. The chemical activation enabled to form the fibres 250-350 nm in thickness with pore sizes distributed between 0.6 and 0.7 nm and an average specific surface area of $569m^2/g$. The adsorption capacities of pure (100%) and indoor (0.3%) $CO_2$, of which level frequently appears, at the ambient condition were improved from 1.08 and 0.013 to 2.2 and 0.144 mmol/g, respectively. It was found that the adsorption amount of $CO_2$ adsorbed by the chemically activated carbon nanofiber prepared through chemical activation would vary depending on the ratio of specific surface area and micropores. In particular, chemical interaction between adsorbent surface and gas molecules could enhance the selective capture of weak acidic $CO_2$.

• Journal of Korea Foundry Society
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• v.41 no.6
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• pp.550-557
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• 2021

With the advent of the fourth industrial revolution, the interest in the internet of things (IoT) in manufacturing is growing, even at foundries. There are several types of process data that can be automatically collected at a foundry, but considerable amounts of process data are still managed based on handwriting for reasons such as the limited functions of outdated production facilities and process design based on operator know-how. In particular, despite recognizing the importance of converting process data into big data, many companies have difficulty adopting these steps willingly due to the burden of system construction costs. In this study, the field applicability of IoT-based devices was examined by manufacturing devices and applying them directly to the site of a centrifugal foundry. For the centrifugal casting process, the temperature and humidity of the working site, the molten metal temperature, and mold rotation speed were selected as process parameters to be collected. The sensors were selected in consideration of the detailed product specifications and cost required for each process parameter, and the circuit was configured using a NodeMCU board capable of wireless communication for IoT-based devices. After designing the circuit, PCB boards were prepared for each parameter, and each device was installed on site considering the working environment. After the on-site installation process, it was confirmed that the level of satisfaction with the safety of the workers and the efficiency of process management increased. Also, it is expected that it will be possible to link process data and quality data in the future, if process parameters are continuously collected. The IoT-based device designed in this study has adequate reliability at a low cast, meaning that the application of this technique can be considered as a cornerstone of data collecting at foundries.

• The Journal of the Convergence on Culture Technology
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• v.8 no.2
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• pp.367-372
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• 2022

With the recent advent of the New Normal era, realistic technologies and non-contact technologies are receiving social attention. However, the hair styling field focuses on the direction of the hair itself, individual movements, and modeling, focusing on hair simulation. In order to create an improved practice environment and demand of the times, this study proposed a non-contact hair styling VR system. In the theoretical review, we studied the existing cases of hair cut research. Existing haircut-related research tend to be mainly focused on force-based feedback. Research on the interactive haircut work in the virtual environment as addressed in this paper has not been done yet. VR controllers capable of finger tracking the movements necessary for beauty enable selection, cutting, and rotation of beauty tools, and built a non-contact collaboration environment. As a result, we conducted two experiments for interactive hair cutting in VR. First, it is a haircut operation for synchronization using finger tracking and holding hook animation. We made position correction for accurate motion. Second, it is a real-time interactive cutting operation in a multi-user virtual collaboration environment. This made it possible for instructors and learners to communicate with each other through VR HMD built-in microphones and Photon Voice in non-contact situations.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.26 no.2
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• pp.63-81
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• 2021

In this study, we investigated the tide-induced flow patterns near the ocean outfall of the Jeju and Bomok Wastewater Treatment Plants (WTP) in Jeju Island by using measurements of Acoustic Doppler Current Meter (ADCP) and a numerical experiment with inserting passive tracer into a regional ocean model. In late spring of 2018, the ADCP measurements showed that tidal currents dominate the flow patterns as compared to the non-tidal components in the outfall regions. According to harmonic analysis, the dominant type of tides is mixed of diurnal and semi-diurnal but predominantly semidiurnal, showing stronger oscillations in the Jeju WTP than those in the Bomok WTP. The tidal currents oscillate parallel to the isobath in both regions, but the rotating direction is different each other: an anti-clockwise direction in the Jeju WTP and a clockwise in the Bomok WTP. Of particular interest is the finding that the residual current mainly flows toward the coastline across the isobath, especially at the outfall of the Bomok WTP. Our model successfully captures the features of tidal currents observed near the outfall in both regions and indicates possibly high persistent pollutant accumulation along the coasts of Bomok.

• Journal of the Korean Society of Marine Environment & Safety
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• v.28 no.6
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• pp.1054-1062
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• 2022

The population of Korea's solar salt-producing regions is rapidly aging, resulting in a decrease in the number of productive workers. In solar salt production, salt collection is the most labor-intensive operation because existing salt collection vehicles require human operators. Therefore, we intend to develop an unmanned solar salt collection vehicle to reduce manpower requirements. The unmanned solar salt collection vehicle is designed to identify the salt collection status and location in the salt plate via color detection, the color detection performance is a crucial consideration. Therefore, an image processing algorithm was developed to improve color detection performance. The algorithm generates an around-view image by using resizing, rotation, and perspective transformation of the input image, set the RoI to transform only the corresponding area to the HSV color model, and detects the color area through an AND operation. The detected color area was expanded and noise removed using morphological operations, and the area of the detection region was calculated using contour and image moment. The calculated area is compared with the set area to determine the location case of the collection vehicle within the salt plate. The performance was evaluated by comparing the calculated area of the final detected color to which the algorithm was applied and the area of the detected color in each step of the algorithm. It was confirmed that the color detection performance is improved by at least 25-99% for salt detection, at least 44-68% for red color, and an average of 7% for blue and an average of 15% for green. The proposed approach is well-suited to the operation of unmanned solar salt collection vehicles.

• Journal of the Korean Arthroscopy Society
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• v.9 no.2
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• pp.222-231
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• 2005

Purpose: This article describes a double-bundle ACL reconstruction technique using a five-strand hamstring tendon autograft with conventional anteromedial bundle reconstruction and additional posterolateral bundle reconstruction. Operative technique: For the tibial tunnel, the conventional single tunnel technique is performed and for the femoral tunnel, the double tunnel technique is performed with the anteromedial and posterolateral bundle. After minimal notchplasty, the anteromedial femoral tunnel is prepared with leaving one milimeter of posterior femoral cortex within the over-the-top, which if positioned at the 11-o'clock orientation for the right knee or at the 1-o'clock position for the left knee. The posterolateral femoral tunnel that is located 5 to 7 mm superior to the inner margin of the lateral meniscus anterior horn at $90^{\circ}$ of flexion is prepared with tile outside-in technique using a 4.5 cannulated reamer. The graft material for the double bundle reconstruction is made of the conventional four-strand hamstring autograft in the anteromedial bundle and of a single-strand semitendinosus tendon in the posterolateral bundle. The anteromedial bundle is fixed with using a rigid fix system on the femoral side and the posterolateral bundle is fixed to tie with the miniplate from the outside femur. Then, with the knee in $10^{\circ}\;to\;20^{\circ}$ of flexion, a bioabsorbable screw is simultaneously applied to achieve tibial fixation with tensioning of both bundles. Conclusion: A double bundle reconstruction with five-strand hamstring autograft, which is designed with a favorable conventional anteromedial bundle and an additional posterolateral bundle to restore rotation stability, seems to be a very effective method for the treatment for ACL instabilities.

• Proceedings of the Korea Association of Crystal Growth Conference
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• 1996.06b
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• pp.219-222
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• 1996

수열법은 밀폐용기중에서 10$0^{\circ}C$이상의 가열, 가압된 수용액이 반응에 관여하는 것으로써, 수정, CaCO3, AlPO4, GaPO4 등과 같은 단결정의 육성 뿐만 아니라 균일분산계로부터 균일한 결정성의 미립자 합성에도 폭넓게 이용되고 있다. 세라믹분말의 합성에 있어서, 이 방법은 특히 형상, 입자크기의 제어가 용이할 뿐만 아니라 고상법, 졸-겔법, 공침법에서와 같은 열처리, 분쇄과정이 필요없기 때문에 고순도의 초미립자를 얻을 수 있는 장점이 있다. 근년 미국, 일본에서는 수열법을 이용한 유전, 압전체 등 세라믹분말의 일부가 공업적인 규모로 대량 생산되고 있다. 그러나 이에 대한 국내 기술은 아직 초기단계에 이르고 있는 실정이다. 따라서 본 연구실에서는 수열법에 의한 단결정 육성 (예; 자수정, CaCO3, AlPO4, GaPO4, KTP, Emerald 등), 박막제조 (예; GaP, PbTiO3, BaTiO3 등), 정제 (고령토, 장석, 도석 등), 원석처리 (진주, 인공 emerald, 비취 등) 그리고 각종 세라믹분말의 합성 등과 같은 다양한 기반기술의 축적과 동시에 공업화에 대응한 수열장치를 위하여 반응용기의 대형화, 엄밀한 밀폐방식, 실용적인 수열조건 등을 개발해 오고 있다. 본 발표에서는 현재까지의 연구개발 내용 중에서 결정성 미립자에 관련한 세라믹분말의 합성에 대한 일부의 결과들을 보고한다. 일반적으로 수열장치는 전기로, 반응용기, 온도 및 압력제어계 등을 기본으로 하고 있으며 시판용의 대부분이 교반기가 부착된 수직형 (vertical type)이다. 이와 같은 방식에 있어서는 엄밀한 밀폐가 곤란, 반응온도의 한계성 (25$0^{\circ}C$ 이하), 증진율의 한계성 (소량생산) 등과 같은 점이 있기 때문에 본 연구실에서는 개폐식 전기로내에 엄밀한 밀폐가 가능한 수평식(horizontal type)의 반응용기를 채택한 뒤 이를 회전 또는 시이소(seesaw)식으로 움직일 수 있도록 하여 연속공정화, 온도구배의 자율조절 그리고 보다 저온에서도 인위적인 이온의 확산을 효율적으로 유도할 수 있도록 하였다. 이와 같은 방식은 기존의 방식과 비교하여 반응용기 내에 응집현상과 미반응물이 존재하지 않으며 또한 단분산으로 결정성 미립자를 대량적으로 얻을 수 있는 장점이 있었다. 다음은 이상과 같이 본 연구실에서 자체 개발한 수열장치를 이용하여 PbTiO3, (Pb,La)TiO3Mn, BaTiO3, ZnSiO4:Mn, CaWO4 등과 같은 세라믹분말에 대한 합성 실험의 결과이다. 압전성, 초전성이 우수한 PbTiO3 및 (Pb,La)TiO3:Mn 분말의 수열합성은 PbO, TiO2, La2O3 등의 분말을 출발원료로 하여 합성도도 25$0^{\circ}C$부근의 알카리성 용액중에서 결정성 PbTiO3 및 (Pb,La)TiO3:Mn 미립자를 단상으로 얻었으며 입자의 형상 및 크기는 합성온도와 수열용매의 종류에 의존하였다. 유전체로서 폭넓게 응용되고 있는 BaTiO3 분말은 Ba(OH)2.8H2O, TiO2와 같은 최적의 출발원료를 선택함으로써 15$0^{\circ}C$ 부근의 저온영역에서도 용이하게 합성할 수 있었다. 특히 본 연구에서는 수용성인 Ba(OH)2.8H2O를 사용함으로써 host-guest적인 반응을 유도시키는데 있어 물의 가장 실용적이고 효과적인 수열용매임도 알았다. ZnSiO4:Mn, CaWO4, MgWO4와 같은 형광체 분말은 공업적으로 고상반응 또는 습식법에 의해 얻어지고 있으나 이들 방법에 있어서는 분쇄공정으로 인한 형광특성의 저하와 같은 문제점이 있다. 따라서 본 연구에서는 수열법을 이용하여 이들 화합물의 합성을 시도하였으며 그 결과 합성온도 30$0^{\circ}C$ 부근의 알칼리성 용액중에서 수열적으로 얻어짐을 알았다. 여기서의 합성분말을 이용하여 실제 조명램프로 제조한 결과 녹색, 청색 발광용 형광체로서 우수한 형광특성을 나타내었다. 천연에서 소량 산출되고 있는 고가의 (Li,Al)MnO2(OH)2:Co 분말은 도자기의 전사지용 청색안료로써 이용되고 있다. 본 연구실에서는 LiOH.H2O, Al(OH)3, MnO2 등의 분말을 출발원료로 하고 24$0^{\circ}C$ 온도 부근 그리고 물을 수열용매로 하여 천연산에 필적하는 (Li,Al)MnO2(OH)2:Co 분말을 인공적으로 합성하였다.

• The korean journal of orthodontics
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• v.30 no.5 s.82
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• pp.509-519
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• 2000

Enlow's counterpart analysis explains the complex with anatomic and developmental characteristics where craniofacial aspect of individuals has been developed. The analysis does not compare individual measurement with the normal value from the average of majority but analyzes by comparison of values that each individual has. This study was to clarify the Korean craniofacial skeletal pattern using Enlow's counterpart analysis considering the fact that the craniofacial skeletal pattern has racial and regional variations. This research will be helpful in the future for growth research and research of the orthognathic surgery. For this study, the samples were consisted of 100 Korean adult subjects(50 males and 50 females) who had normal occlusion and pleasing face. Measurement points and lines were established using Enlow's counterpart analysis and they were statistically evaluated. The results indicated that : 1. The average angle between PCF and PMV was $38.54^{\circ}$ in males and $38.43^{\circ}$ in females, and the average Wits' appraisal was -2.51 in males and -2.3 in females. The ramus alignment(R4) was 1.89 in males and 2.36 in females. 2. It shows that females have a longer ramus than the PCF compared to the males, because there was a significant difference in Ramus/PCF horizontal dimensions (Skeletal A3-B3) between female and male subjects 3. It shows that males have a longer mandibular corpus than the maxilla compared to the females, because there was a significant difference in Maxillary/Mandibular arches(Skeletal A4-B4) between male and female subjects 4. In cranial floor+maxilla/ramus+corpus at A and B points(Al-Bl), which represents difference in total horizontal length between the maxilla and mandible, there was no significant difference between males and females. In conclusions, compared to Caucasian, Korean have more depressed midface, prognathic mandible, and ramus that rotates inferioposterior. Also, we observe that Korean women have target ramus posterior cranial base, as compared with Korean men. Consequently, the total length of maxilla and mandible does not show any difference, because man's mandible is longer than maxilla in comparison with woman's one.

• Asian Journal of Turfgrass Science
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• v.23 no.1
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• pp.151-162
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• 2009

When viewing that since the 1990s local governments have tried to build golf courses as a plan to revitalize the attraction of home and abroad tourists and to increase their tax incomes and that big companies are interested in leisure business including golf courses as a future promising business in the 21st century, golf courses seem to continuously increase in the future. On the contrary, noticing that golf courses are not only the main culprit behind the damage of natural environment and environmental pollution but also a target of real estate speculation and that golf makes a sense of incongruity between the classes of a society as a luxury sports, environment activists and local residents raise criticism to golf. Golf in our country shows a special sports phenomenon of which the pros and cons appear continuously. So, it is judged that policy for golf development direction should be set up based on verified scientific data. Thus, the research aims at deriving the location types of golf courses by looking at laws from the period of formation of the initial domestic golf courses to the recent period, grasping their distribution status according to time series and regions, conducting a questionnaire survey regarding location factors for golfers and the workers of golf courses, and dividing golf courses into several types. It is expected that the research will be a fundamental material when a golf course is built later on, contributing to the research of golf courses.

• Korean Journal of Psychosomatic Medicine
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• v.27 no.2
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• pp.77-84
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• 2019

Objectives : The Illness Intrusiveness Rating Scale (IIRS) is a well-validated self-report instrument for assessing negative impact of chronic illness and/or adverse effects of its treatment on everyday life domains. Although extensive literature probed its psychometric properties in medical illness, little attention was paid for its validity for psychiatric population. This study aimed to test factorial structure of the Korean Version of the IIRS (IIRS-K) in a consecutive sample of psychiatric outpatients. Methods : Data set of 307 first-visit patients of psychiatric clinic at Guri Hanyang univ. Hospital were used. Exploratory and confirmatory factor analysis, internal consistency were tested in IIRS-K. We also checked Spearman's correlation analysis between IIRS-K, Zung's self-report anxiety scale and Zung's self-report depression scale. Results : 76.9% of the patients were with anxiety disorder and depressive disorder. The principal component factor analysis of the IIRS-K extracted three-factor structure accounted for 63.2% of total variance that was contextually similar to the original English version. This three-factor solution showed the best fit when tested confirmatory factor analysis compared to the original IIRS, two-factor model of IIRS-K suggested from medical outpatients, and one-factor solution. The IIRS-K also showed good internal consistency (Cronbach's α=0.90) and good convergent validity with anxiety and depression scales. Conclusions : The IIRS-K showed the three-factor structure that was similar but not identical to original version. Overall, this study proved factorial validity of the IIRS-K and it can be used for Korean clinical population.