Newly Designed HRTF Measuring System

Yunjae Lee,Youngjin Park,Youn-sik Park 제어로봇시스템학회 2009 제어로봇시스템학회 국제학술대회 논문집 Vol.2009 No.8

Because people expect better sound reproduction that offers more realistic experience, 3D sound technologies are ceaselessly being improved. When we render 3D sound image using headphones or speakers, the main key of this technology is the Head-related transfer function (HRTF) database. Even though there are various HRTF databases they have some drawbacks such as detrimental effects caused by imperfect measuring environment and insufficient measurement points. In addition to those problems, there is no database aimed at Korean even if the HRTFs vary from person to person. Therefore we are planning to develop the HRTF database for Korean. As a first step to do it, the new HRTF measuring system without aforementioned drawbacks is designed. In this paper, the newly designed HRTF measuring system is introduced and the overall effects are analyzed caused by the diffraction of the apparatus, especially the headrest and backrest of the chair.

Fabrication of Electro-active Polymer Actuator Based on Transparent Graphene Electrode

Yunjae Park,Hyonkwang Choi,Kihong Im,Seonpil Kim,Minhyon Jeon 한국진공학회 2014 한국진공학회 학술발표회초록집 Vol.2014 No.2

The Work of Sherwood Hall and the Haiju Tuberculosis Sanatorium in Colonial Korea

PARK Yunjae 대한의사학회 2013 의사학(醫史學) Vol.22 No.3

Development of a novel testis-on-a-chip that demonstrates reciprocal crosstalk between Sertoli and Leydig cells in testicular tissue

Park Se-Ra,Kook Myung Geun,Kim Soo-Rim,Lee Choon-Mi,Lee Jin Woo,Park Jung-Kyu,Park Chan Hum,Oh Byung-Chul,Jung YunJae,Hong In-Sun 생화학분자생물학회 2024 Experimental and molecular medicine Vol.56 No.-

The reciprocal crosstalk between testicular Sertoli and Leydig cells plays a vital role in supporting germ cell development and maintaining testicular characteristics and spermatogenesis. Conventional 2D and the recent 3D assay systems fail to accurately replicate the dynamic interactions between these essential endocrine cells. Furthermore, most in vitro testicular tissue models lack the ability to capture the complex multicellular nature of the testis. To address these limitations, we developed a 3D multicellular testis-on-a-chip platform that effectively demonstrates the reciprocal crosstalk between Sertoli cells and the adjacent Leydig cells while incorporating various human testicular tissue constituent cells and various natural polymers infused with blood coagulation factors. Additionally, we identified SERPINB2 as a biomarker of male reproductive toxicity that is activated in both Sertoli and Leydig cells upon exposure to various toxicants. Leveraging this finding, we designed a fluorescent reporter-conjugated toxic biomarker detection system that enables both an intuitive and quantitative assessment of material toxicity by measuring the converted fluorescence intensity. By integrating this fluorescent reporter system into the Sertoli and Leydig cells within our 3D multicellular chip platform, we successfully developed a testis-on-chip model that can be utilized to evaluate the male reproductive toxicity of potential drug candidates. This innovative approach holds promise for advancing toxicity screening and reproductive research.

Vulvar Reconstruction Using Keystone Flaps Based on the Perforators of Three Arteries

Yunjae Lee,Sanghun Lee,Dongkyu Lee,Hyeonjung Yeo,Hannara Park,Hyochun Park 대한성형외과학회 2022 Archives of Plastic Surgery Vol.49 No.6

Various flaps are used to reconstruct skin and soft tissue defects of the vulva following resection of malignancies. Whenever possible, reconstruction using local flaps is the standard treatment. Here, we describe vulvar defect reconstruction using keystone flaps. Standard keystone flaps are based on randomly located vascular perforators. However, we designed a keystone flap that includes perforators of three named arteries (the anterior labial artery of the external pudendal artery, cutaneous branches of the obturator artery, and posterior labial artery of the internal pudendal artery) and the pudendal nerve, which accompanies the internal pudendal artery. Four patients with squamous cell carcinoma and extramammary Paget’s disease of the vulva underwent radical vulvectomy and keystone flaps including perforators of three arteries. Depending on the morphology of the defects, keystone flaps were used with different designs. For elliptical and unilateral vulvar defects, a standard keystone flap was designed, and for defects on both sides of the vulva, a double opposing keystone flap was used. For oval defects, the omega variant keystone flap was designed, and when the morphology of the defect needed rotation of the flap, a rotational keystone flap was designed. All the patients showed good function and sensation, with an acceptable cosmetic appearance.

Anti-Cholera Measures by the Japanese Colonial Government and the Reaction of Koreans in the Early 1920s

Park Yunjae The Academy of Korean Studies 2005 THE REVIEW OF KOREAN STUDIES Vol.8 No.4

Surgical refinement of the purse-string suture for skin and soft tissue defects of the head and neck

Park, Hyochun,Lee, Yunjae,Yeo, Hyeonjung,Park, Hannara Korean Cleft Palate-Craniofacial Association 2021 Archives of Craniofacial Surgery Vol.22 No.4

Background: The purse-string suture (PSS) is a simple and rapid wound closure method that results in minimal scarring. It has been used to treat circular or oval skin defects caused by tumor excision or trauma. However, due to obscurity, it is not widely used, especially for the head and neck. This study aimed to modify the PSS to obtain predictable and acceptable results. Methods: A total of 45 sites in 39 patients with various types of skin and soft tissue defects in the head and neck were treated with PSS. We used PDS II (2-0 to 5-0), which is an absorbable suture. Minimal dissection of the subcutaneous layer was performed. The suture knot was hidden by placing it in the dissection layer. Depending on the characteristics of the skin and soft tissue defects, additional surgical interventions such as side-to-side advancement sutures, double PSS, or split-thickness skin graft were applied. Results: All wounds healed completely without any serious complications. Large defects up to 45 mm in diameter were successfully reconstructed using only PSS. Postoperative radiating folds were almost flattened after approximately 1-2 months. Conclusion: PSS is simple, rapid, and relatively free from surgical design. Owing to the circumferential advancement of the surrounding tissue, PSS always results in a smaller scar than the initial lesion and less distortion of the body structures around the wound in the completely healed defect. If the operator can predict the process of healing and immediate radiating folds, PSS could be a favorable option for round skin defects in the head and neck.

Sanitizing Korea: Anti-Cholera Activities of the Police in Early Colonial Korea

( Park Yunjae ) 서울대학교 규장각한국학연구원 2010 Seoul journal of Korean studies Vol.23 No.2

The Gabo Reform cabinet in 1894 instituted the sanitary police system. With no cure or vaccine for epidemics available and few Western-trained doctors, the task of implementing disinfection and quarantine had to be taken up by the police. However, the sanitary police active in late Joseon Korea worked under civilian supervision. After the Protectorate Treaty of 1905, Japan changed the sanitary police system in Korea, reinforcing the role and the responsibility of the police. Unlike the Korean government, the colonial authority saw police enforcement as the mainstay of administrative implementation. The police-centered sanitizing system was fully established in 1911 when the full responsibility for sanitation work was transferred to the police. Whenever cholera raged through Korea, one of the first measures the Japanese colonial government took was to inspect sea vessels and trains. It was the police who were sent to examine the vessels and crews and also to see to the implementation of quarantine. Vaccination was regarded as the most effective preventive measure and the police controlled all aspects of vaccination campaigns. The most critical mission the police were assigned to carry out was house inspection. The police-centered anti-cholera activities seemed to work. With the exception of the years 1919, 1920 and 1926, colonial Korea did not see as many casualties from cholera as Japan did during the same period. However, the anti-cholera activities carried out by the police often encountered a hostile response from the people. Some expressed doubts about the police-centered anti-epidemic activities, arguing that the colonial government should provide sanitation education, not forced sanitation. But the key aspects of the police-centered sanitary system did not change. The successive budget cuts, together with the colonial government’s desire to control its subjects, prevented the rise of an adequate sanitary infrastructure, and led to the colonizers’ continued reliance on the sanitary police system.

Fabrication and Characterization of Graphene-Based Electrochemical Sensors for Glucose Measurement

Park, Minjeong,Choi, Hyonkwang,Park, Yunjae,Lee, Wookyoung,Lee, Jewon,Jeon, Minhyon American Scientific Publishers 2015 Journal of Nanoscience and Nanotechnology Vol.15 No.10

방역에서 강제와 협조의 조화? - 식민지 시기를 중심으로

박윤재(Park Yunjae) 역사비평사 2020 역사비평 Vol.- No.131

During the colonial period, damage from infectious disease was substantial. Infectious disease was an obstacle to stable ruling of the colony. Police force was at the center of prevention against infectious disease, and as such, it was violent and oppressive. Since disease prevention required forceful measures, a certain extent of coercion was unavoidable, and even effective. A good example is preventive efforts against the plague that took place in the Manchuria in 1910 through 1911. Despite the absence of vaccine or treatment against the plague, not a single person was infected. Problem was that coercion alone was insufficient for efficient prevention of disease. In the 1920s, Korean people resisted preventive measures taken by the colonial government against the cholera, and they sought alternative measures. Specifically, they attempted to establish a Korean hospital that is run by Korean people and applies Korean-style treatment. At the place, both western and Korean traditional medicine could be dispensed depending on a patient’s condition or request. In prevention of infectious disease, Korean traditional medicine was useful in seeking cooperation from the Korean. Choosing either coercion or autonomy is undesirable in making efforts for disease prevention. What is important is to identify an adequate approach depending on specific circumstances. However, it is hard to find a perfect measure that takes into account all factors, and thus, the second-best measure needs to be sought. And one of the ways to do so is to obtain understanding of the society.